Add nullability annotations to Java generated clients (#19617)

* issue-1960: Add nullability annotations to Java generated clients

Motivations:
Have generated clients properly annotated for nullability to be able to check code using them with tools like NullAway

Modifications:
* Add nullable_var_annotations template to handle nullability annotation on vars
* Add pojo templates to use the nullability template
* Adapt tests

* issue-1960: Add nullability annotations to Java generated clients

Modifications:
* Run export_docs_generator.sh script to update samples

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java

@@ -55,40 +55,48 @@ import org.openapitools.client.JSON;
 public class AdditionalPropertiesClass {
   public static final String SERIALIZED_NAME_MAP_PROPERTY = "map_property";
   @SerializedName(SERIALIZED_NAME_MAP_PROPERTY)
+  @javax.annotation.Nullable
   private Map<String, String> mapProperty = new HashMap<>();
 
   public static final String SERIALIZED_NAME_MAP_OF_MAP_PROPERTY = "map_of_map_property";
   @SerializedName(SERIALIZED_NAME_MAP_OF_MAP_PROPERTY)
+  @javax.annotation.Nullable
   private Map<String, Map<String, String>> mapOfMapProperty = new HashMap<>();
 
   public static final String SERIALIZED_NAME_ANYTYPE1 = "anytype_1";
   @SerializedName(SERIALIZED_NAME_ANYTYPE1)
+  @javax.annotation.Nullable
   private Object anytype1 = null;
 
   public static final String SERIALIZED_NAME_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE1 = "map_with_undeclared_properties_anytype_1";
   @SerializedName(SERIALIZED_NAME_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE1)
+  @javax.annotation.Nullable
   private Object mapWithUndeclaredPropertiesAnytype1;
 
   public static final String SERIALIZED_NAME_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE2 = "map_with_undeclared_properties_anytype_2";
   @SerializedName(SERIALIZED_NAME_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE2)
+  @javax.annotation.Nullable
   private Object mapWithUndeclaredPropertiesAnytype2;
 
   public static final String SERIALIZED_NAME_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE3 = "map_with_undeclared_properties_anytype_3";
   @SerializedName(SERIALIZED_NAME_MAP_WITH_UNDECLARED_PROPERTIES_ANYTYPE3)
+  @javax.annotation.Nullable
   private Map<String, Object> mapWithUndeclaredPropertiesAnytype3 = new HashMap<>();
 
   public static final String SERIALIZED_NAME_EMPTY_MAP = "empty_map";
   @SerializedName(SERIALIZED_NAME_EMPTY_MAP)
+  @javax.annotation.Nullable
   private Object emptyMap;
 
   public static final String SERIALIZED_NAME_MAP_WITH_UNDECLARED_PROPERTIES_STRING = "map_with_undeclared_properties_string";
   @SerializedName(SERIALIZED_NAME_MAP_WITH_UNDECLARED_PROPERTIES_STRING)
+  @javax.annotation.Nullable
   private Map<String, String> mapWithUndeclaredPropertiesString = new HashMap<>();
 
   public AdditionalPropertiesClass() {
   }
 
-  public AdditionalPropertiesClass mapProperty(Map<String, String> mapProperty) {
+  public AdditionalPropertiesClass mapProperty(@javax.annotation.Nullable Map<String, String> mapProperty) {
     this.mapProperty = mapProperty;
     return this;
   }
@@ -110,12 +118,12 @@ public class AdditionalPropertiesClass {
     return mapProperty;
   }
 
-  public void setMapProperty(Map<String, String> mapProperty) {
+  public void setMapProperty(@javax.annotation.Nullable Map<String, String> mapProperty) {
     this.mapProperty = mapProperty;
   }
 
 
-  public AdditionalPropertiesClass mapOfMapProperty(Map<String, Map<String, String>> mapOfMapProperty) {
+  public AdditionalPropertiesClass mapOfMapProperty(@javax.annotation.Nullable Map<String, Map<String, String>> mapOfMapProperty) {
     this.mapOfMapProperty = mapOfMapProperty;
     return this;
   }
@@ -137,12 +145,12 @@ public class AdditionalPropertiesClass {
     return mapOfMapProperty;
   }
 
-  public void setMapOfMapProperty(Map<String, Map<String, String>> mapOfMapProperty) {
+  public void setMapOfMapProperty(@javax.annotation.Nullable Map<String, Map<String, String>> mapOfMapProperty) {
     this.mapOfMapProperty = mapOfMapProperty;
   }
 
 
-  public AdditionalPropertiesClass anytype1(Object anytype1) {
+  public AdditionalPropertiesClass anytype1(@javax.annotation.Nullable Object anytype1) {
     this.anytype1 = anytype1;
     return this;
   }
@@ -156,12 +164,12 @@ public class AdditionalPropertiesClass {
     return anytype1;
   }
 
-  public void setAnytype1(Object anytype1) {
+  public void setAnytype1(@javax.annotation.Nullable Object anytype1) {
     this.anytype1 = anytype1;
   }
 
 
-  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype1(Object mapWithUndeclaredPropertiesAnytype1) {
+  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype1(@javax.annotation.Nullable Object mapWithUndeclaredPropertiesAnytype1) {
     this.mapWithUndeclaredPropertiesAnytype1 = mapWithUndeclaredPropertiesAnytype1;
     return this;
   }
@@ -175,12 +183,12 @@ public class AdditionalPropertiesClass {
     return mapWithUndeclaredPropertiesAnytype1;
   }
 
-  public void setMapWithUndeclaredPropertiesAnytype1(Object mapWithUndeclaredPropertiesAnytype1) {
+  public void setMapWithUndeclaredPropertiesAnytype1(@javax.annotation.Nullable Object mapWithUndeclaredPropertiesAnytype1) {
     this.mapWithUndeclaredPropertiesAnytype1 = mapWithUndeclaredPropertiesAnytype1;
   }
 
 
-  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype2(Object mapWithUndeclaredPropertiesAnytype2) {
+  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype2(@javax.annotation.Nullable Object mapWithUndeclaredPropertiesAnytype2) {
     this.mapWithUndeclaredPropertiesAnytype2 = mapWithUndeclaredPropertiesAnytype2;
     return this;
   }
@@ -194,12 +202,12 @@ public class AdditionalPropertiesClass {
     return mapWithUndeclaredPropertiesAnytype2;
   }
 
-  public void setMapWithUndeclaredPropertiesAnytype2(Object mapWithUndeclaredPropertiesAnytype2) {
+  public void setMapWithUndeclaredPropertiesAnytype2(@javax.annotation.Nullable Object mapWithUndeclaredPropertiesAnytype2) {
     this.mapWithUndeclaredPropertiesAnytype2 = mapWithUndeclaredPropertiesAnytype2;
   }
 
 
-  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype3(Map<String, Object> mapWithUndeclaredPropertiesAnytype3) {
+  public AdditionalPropertiesClass mapWithUndeclaredPropertiesAnytype3(@javax.annotation.Nullable Map<String, Object> mapWithUndeclaredPropertiesAnytype3) {
     this.mapWithUndeclaredPropertiesAnytype3 = mapWithUndeclaredPropertiesAnytype3;
     return this;
   }
@@ -221,12 +229,12 @@ public class AdditionalPropertiesClass {
     return mapWithUndeclaredPropertiesAnytype3;
   }
 
-  public void setMapWithUndeclaredPropertiesAnytype3(Map<String, Object> mapWithUndeclaredPropertiesAnytype3) {
+  public void setMapWithUndeclaredPropertiesAnytype3(@javax.annotation.Nullable Map<String, Object> mapWithUndeclaredPropertiesAnytype3) {
     this.mapWithUndeclaredPropertiesAnytype3 = mapWithUndeclaredPropertiesAnytype3;
   }
 
 
-  public AdditionalPropertiesClass emptyMap(Object emptyMap) {
+  public AdditionalPropertiesClass emptyMap(@javax.annotation.Nullable Object emptyMap) {
     this.emptyMap = emptyMap;
     return this;
   }
@@ -240,12 +248,12 @@ public class AdditionalPropertiesClass {
     return emptyMap;
   }
 
-  public void setEmptyMap(Object emptyMap) {
+  public void setEmptyMap(@javax.annotation.Nullable Object emptyMap) {
     this.emptyMap = emptyMap;
   }
 
 
-  public AdditionalPropertiesClass mapWithUndeclaredPropertiesString(Map<String, String> mapWithUndeclaredPropertiesString) {
+  public AdditionalPropertiesClass mapWithUndeclaredPropertiesString(@javax.annotation.Nullable Map<String, String> mapWithUndeclaredPropertiesString) {
     this.mapWithUndeclaredPropertiesString = mapWithUndeclaredPropertiesString;
     return this;
   }
@@ -267,7 +275,7 @@ public class AdditionalPropertiesClass {
     return mapWithUndeclaredPropertiesString;
   }
 
-  public void setMapWithUndeclaredPropertiesString(Map<String, String> mapWithUndeclaredPropertiesString) {
+  public void setMapWithUndeclaredPropertiesString(@javax.annotation.Nullable Map<String, String> mapWithUndeclaredPropertiesString) {
     this.mapWithUndeclaredPropertiesString = mapWithUndeclaredPropertiesString;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOf.java

@@ -54,24 +54,28 @@ import org.openapitools.client.JSON;
 public class AllOfModelArrayAnyOf {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name = "default-name";
 
   public static final String SERIALIZED_NAME_LINK_LIST_COLUMN1 = "linkListColumn1";
   @SerializedName(SERIALIZED_NAME_LINK_LIST_COLUMN1)
+  @javax.annotation.Nullable
   private AllOfModelArrayAnyOfAllOfLinkListColumn1 linkListColumn1;
 
   public static final String SERIALIZED_NAME_ATTRIBUTES = "attributes";
   @SerializedName(SERIALIZED_NAME_ATTRIBUTES)
+  @javax.annotation.Nullable
   private AllOfModelArrayAnyOfAllOfAttributes attributes;
 
   public AllOfModelArrayAnyOf() {
   }
 
-  public AllOfModelArrayAnyOf id(Long id) {
+  public AllOfModelArrayAnyOf id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -85,12 +89,12 @@ public class AllOfModelArrayAnyOf {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public AllOfModelArrayAnyOf name(String name) {
+  public AllOfModelArrayAnyOf name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -104,12 +108,12 @@ public class AllOfModelArrayAnyOf {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public AllOfModelArrayAnyOf linkListColumn1(AllOfModelArrayAnyOfAllOfLinkListColumn1 linkListColumn1) {
+  public AllOfModelArrayAnyOf linkListColumn1(@javax.annotation.Nullable AllOfModelArrayAnyOfAllOfLinkListColumn1 linkListColumn1) {
     this.linkListColumn1 = linkListColumn1;
     return this;
   }
@@ -123,12 +127,12 @@ public class AllOfModelArrayAnyOf {
     return linkListColumn1;
   }
 
-  public void setLinkListColumn1(AllOfModelArrayAnyOfAllOfLinkListColumn1 linkListColumn1) {
+  public void setLinkListColumn1(@javax.annotation.Nullable AllOfModelArrayAnyOfAllOfLinkListColumn1 linkListColumn1) {
     this.linkListColumn1 = linkListColumn1;
   }
 
 
-  public AllOfModelArrayAnyOf attributes(AllOfModelArrayAnyOfAllOfAttributes attributes) {
+  public AllOfModelArrayAnyOf attributes(@javax.annotation.Nullable AllOfModelArrayAnyOfAllOfAttributes attributes) {
     this.attributes = attributes;
     return this;
   }
@@ -142,7 +146,7 @@ public class AllOfModelArrayAnyOf {
     return attributes;
   }
 
-  public void setAttributes(AllOfModelArrayAnyOfAllOfAttributes attributes) {
+  public void setAttributes(@javax.annotation.Nullable AllOfModelArrayAnyOfAllOfAttributes attributes) {
     this.attributes = attributes;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfAttributes.java

@@ -53,12 +53,13 @@ import org.openapitools.client.JSON;
 public class AllOfModelArrayAnyOfAllOfAttributes {
   public static final String SERIALIZED_NAME_C = "C";
   @SerializedName(SERIALIZED_NAME_C)
+  @javax.annotation.Nullable
   private AllOfModelArrayAnyOfAllOfAttributesC C;
 
   public AllOfModelArrayAnyOfAllOfAttributes() {
   }
 
-  public AllOfModelArrayAnyOfAllOfAttributes C(AllOfModelArrayAnyOfAllOfAttributesC C) {
+  public AllOfModelArrayAnyOfAllOfAttributes C(@javax.annotation.Nullable AllOfModelArrayAnyOfAllOfAttributesC C) {
     this.C = C;
     return this;
   }
@@ -72,7 +73,7 @@ public class AllOfModelArrayAnyOfAllOfAttributes {
     return C;
   }
 
-  public void setC(AllOfModelArrayAnyOfAllOfAttributesC C) {
+  public void setC(@javax.annotation.Nullable AllOfModelArrayAnyOfAllOfAttributesC C) {
     this.C = C;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AllOfModelArrayAnyOfAllOfLinkListColumn1.java

@@ -55,12 +55,13 @@ import org.openapitools.client.JSON;
 public class AllOfModelArrayAnyOfAllOfLinkListColumn1 {
   public static final String SERIALIZED_NAME_VALUE = "value";
   @SerializedName(SERIALIZED_NAME_VALUE)
+  @javax.annotation.Nonnull
   private List<AllOfModelArrayAnyOfAllOfLinkListColumn1Value> value = new ArrayList<>();
 
   public AllOfModelArrayAnyOfAllOfLinkListColumn1() {
   }
 
-  public AllOfModelArrayAnyOfAllOfLinkListColumn1 value(List<AllOfModelArrayAnyOfAllOfLinkListColumn1Value> value) {
+  public AllOfModelArrayAnyOfAllOfLinkListColumn1 value(@javax.annotation.Nonnull List<AllOfModelArrayAnyOfAllOfLinkListColumn1Value> value) {
     this.value = value;
     return this;
   }
@@ -82,7 +83,7 @@ public class AllOfModelArrayAnyOfAllOfLinkListColumn1 {
     return value;
   }
 
-  public void setValue(List<AllOfModelArrayAnyOfAllOfLinkListColumn1Value> value) {
+  public void setValue(@javax.annotation.Nonnull List<AllOfModelArrayAnyOfAllOfLinkListColumn1Value> value) {
     this.value = value;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Animal.java

@@ -52,17 +52,19 @@ import org.openapitools.client.JSON;
 public class Animal {
   public static final String SERIALIZED_NAME_CLASS_NAME = "className";
   @SerializedName(SERIALIZED_NAME_CLASS_NAME)
+  @javax.annotation.Nonnull
   protected String className;
 
   public static final String SERIALIZED_NAME_COLOR = "color";
   @SerializedName(SERIALIZED_NAME_COLOR)
+  @javax.annotation.Nullable
   private String color = "red";
 
   public Animal() {
     this.className = this.getClass().getSimpleName();
   }
 
-  public Animal className(String className) {
+  public Animal className(@javax.annotation.Nonnull String className) {
     this.className = className;
     return this;
   }
@@ -76,12 +78,12 @@ public class Animal {
     return className;
   }
 
-  public void setClassName(String className) {
+  public void setClassName(@javax.annotation.Nonnull String className) {
     this.className = className;
   }
 
 
-  public Animal color(String color) {
+  public Animal color(@javax.annotation.Nullable String color) {
     this.color = color;
     return this;
   }
@@ -95,7 +97,7 @@ public class Animal {
     return color;
   }
 
-  public void setColor(String color) {
+  public void setColor(@javax.annotation.Nullable String color) {
     this.color = color;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Apple.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class Apple {
   public static final String SERIALIZED_NAME_CULTIVAR = "cultivar";
   @SerializedName(SERIALIZED_NAME_CULTIVAR)
+  @javax.annotation.Nullable
   private String cultivar;
 
   public static final String SERIALIZED_NAME_ORIGIN = "origin";
   @SerializedName(SERIALIZED_NAME_ORIGIN)
+  @javax.annotation.Nullable
   private String origin;
 
   public Apple() {
   }
 
-  public Apple cultivar(String cultivar) {
+  public Apple cultivar(@javax.annotation.Nullable String cultivar) {
     this.cultivar = cultivar;
     return this;
   }
@@ -75,12 +77,12 @@ public class Apple {
     return cultivar;
   }
 
-  public void setCultivar(String cultivar) {
+  public void setCultivar(@javax.annotation.Nullable String cultivar) {
     this.cultivar = cultivar;
   }
 
 
-  public Apple origin(String origin) {
+  public Apple origin(@javax.annotation.Nullable String origin) {
     this.origin = origin;
     return this;
   }
@@ -94,7 +96,7 @@ public class Apple {
     return origin;
   }
 
-  public void setOrigin(String origin) {
+  public void setOrigin(@javax.annotation.Nullable String origin) {
     this.origin = origin;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/AppleReq.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class AppleReq {
   public static final String SERIALIZED_NAME_CULTIVAR = "cultivar";
   @SerializedName(SERIALIZED_NAME_CULTIVAR)
+  @javax.annotation.Nonnull
   private String cultivar;
 
   public static final String SERIALIZED_NAME_MEALY = "mealy";
   @SerializedName(SERIALIZED_NAME_MEALY)
+  @javax.annotation.Nullable
   private Boolean mealy;
 
   public AppleReq() {
   }
 
-  public AppleReq cultivar(String cultivar) {
+  public AppleReq cultivar(@javax.annotation.Nonnull String cultivar) {
     this.cultivar = cultivar;
     return this;
   }
@@ -75,12 +77,12 @@ public class AppleReq {
     return cultivar;
   }
 
-  public void setCultivar(String cultivar) {
+  public void setCultivar(@javax.annotation.Nonnull String cultivar) {
     this.cultivar = cultivar;
   }
 
 
-  public AppleReq mealy(Boolean mealy) {
+  public AppleReq mealy(@javax.annotation.Nullable Boolean mealy) {
     this.mealy = mealy;
     return this;
   }
@@ -94,7 +96,7 @@ public class AppleReq {
     return mealy;
   }
 
-  public void setMealy(Boolean mealy) {
+  public void setMealy(@javax.annotation.Nullable Boolean mealy) {
     this.mealy = mealy;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayDefault.java

@@ -54,16 +54,18 @@ import org.openapitools.client.JSON;
 public class ArrayDefault {
   public static final String SERIALIZED_NAME_WITH_DEFAULT_EMPTY_BRACKET = "WithDefaultEmptyBracket";
   @SerializedName(SERIALIZED_NAME_WITH_DEFAULT_EMPTY_BRACKET)
+  @javax.annotation.Nullable
   private List<String> withDefaultEmptyBracket = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_WITHOUT_DEFAULT = "WithoutDefault";
   @SerializedName(SERIALIZED_NAME_WITHOUT_DEFAULT)
+  @javax.annotation.Nullable
   private List<String> withoutDefault = new ArrayList<>();
 
   public ArrayDefault() {
   }
 
-  public ArrayDefault withDefaultEmptyBracket(List<String> withDefaultEmptyBracket) {
+  public ArrayDefault withDefaultEmptyBracket(@javax.annotation.Nullable List<String> withDefaultEmptyBracket) {
     this.withDefaultEmptyBracket = withDefaultEmptyBracket;
     return this;
   }
@@ -85,12 +87,12 @@ public class ArrayDefault {
     return withDefaultEmptyBracket;
   }
 
-  public void setWithDefaultEmptyBracket(List<String> withDefaultEmptyBracket) {
+  public void setWithDefaultEmptyBracket(@javax.annotation.Nullable List<String> withDefaultEmptyBracket) {
     this.withDefaultEmptyBracket = withDefaultEmptyBracket;
   }
 
 
-  public ArrayDefault withoutDefault(List<String> withoutDefault) {
+  public ArrayDefault withoutDefault(@javax.annotation.Nullable List<String> withoutDefault) {
     this.withoutDefault = withoutDefault;
     return this;
   }
@@ -112,7 +114,7 @@ public class ArrayDefault {
     return withoutDefault;
   }
 
-  public void setWithoutDefault(List<String> withoutDefault) {
+  public void setWithoutDefault(@javax.annotation.Nullable List<String> withoutDefault) {
     this.withoutDefault = withoutDefault;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java

@@ -55,12 +55,13 @@ import org.openapitools.client.JSON;
 public class ArrayOfArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_NUMBER = "ArrayArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_NUMBER)
+  @javax.annotation.Nullable
   private List<List<BigDecimal>> arrayArrayNumber = new ArrayList<>();
 
   public ArrayOfArrayOfNumberOnly() {
   }
 
-  public ArrayOfArrayOfNumberOnly arrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
+  public ArrayOfArrayOfNumberOnly arrayArrayNumber(@javax.annotation.Nullable List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
     return this;
   }
@@ -82,7 +83,7 @@ public class ArrayOfArrayOfNumberOnly {
     return arrayArrayNumber;
   }
 
-  public void setArrayArrayNumber(List<List<BigDecimal>> arrayArrayNumber) {
+  public void setArrayArrayNumber(@javax.annotation.Nullable List<List<BigDecimal>> arrayArrayNumber) {
     this.arrayArrayNumber = arrayArrayNumber;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOf.java

@@ -55,20 +55,23 @@ import org.openapitools.client.JSON;
 public class ArrayOfInlineAllOf {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name;
 
   public static final String SERIALIZED_NAME_ARRAY_ALLOF_DOG_PROPERTY = "array_allof_dog_property";
   @SerializedName(SERIALIZED_NAME_ARRAY_ALLOF_DOG_PROPERTY)
+  @javax.annotation.Nullable
   private List<ArrayOfInlineAllOfArrayAllofDogPropertyInner> arrayAllofDogProperty = new ArrayList<>();
 
   public ArrayOfInlineAllOf() {
   }
 
-  public ArrayOfInlineAllOf id(Long id) {
+  public ArrayOfInlineAllOf id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -82,12 +85,12 @@ public class ArrayOfInlineAllOf {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public ArrayOfInlineAllOf name(String name) {
+  public ArrayOfInlineAllOf name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -101,12 +104,12 @@ public class ArrayOfInlineAllOf {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public ArrayOfInlineAllOf arrayAllofDogProperty(List<ArrayOfInlineAllOfArrayAllofDogPropertyInner> arrayAllofDogProperty) {
+  public ArrayOfInlineAllOf arrayAllofDogProperty(@javax.annotation.Nullable List<ArrayOfInlineAllOfArrayAllofDogPropertyInner> arrayAllofDogProperty) {
     this.arrayAllofDogProperty = arrayAllofDogProperty;
     return this;
   }
@@ -128,7 +131,7 @@ public class ArrayOfInlineAllOf {
     return arrayAllofDogProperty;
   }
 
-  public void setArrayAllofDogProperty(List<ArrayOfInlineAllOfArrayAllofDogPropertyInner> arrayAllofDogProperty) {
+  public void setArrayAllofDogProperty(@javax.annotation.Nullable List<ArrayOfInlineAllOfArrayAllofDogPropertyInner> arrayAllofDogProperty) {
     this.arrayAllofDogProperty = arrayAllofDogProperty;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfInlineAllOfArrayAllofDogPropertyInner.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class ArrayOfInlineAllOfArrayAllofDogPropertyInner {
   public static final String SERIALIZED_NAME_BREED = "breed";
   @SerializedName(SERIALIZED_NAME_BREED)
+  @javax.annotation.Nullable
   private String breed;
 
   public static final String SERIALIZED_NAME_COLOR = "color";
   @SerializedName(SERIALIZED_NAME_COLOR)
+  @javax.annotation.Nullable
   private String color;
 
   public ArrayOfInlineAllOfArrayAllofDogPropertyInner() {
   }
 
-  public ArrayOfInlineAllOfArrayAllofDogPropertyInner breed(String breed) {
+  public ArrayOfInlineAllOfArrayAllofDogPropertyInner breed(@javax.annotation.Nullable String breed) {
     this.breed = breed;
     return this;
   }
@@ -75,12 +77,12 @@ public class ArrayOfInlineAllOfArrayAllofDogPropertyInner {
     return breed;
   }
 
-  public void setBreed(String breed) {
+  public void setBreed(@javax.annotation.Nullable String breed) {
     this.breed = breed;
   }
 
 
-  public ArrayOfInlineAllOfArrayAllofDogPropertyInner color(String color) {
+  public ArrayOfInlineAllOfArrayAllofDogPropertyInner color(@javax.annotation.Nullable String color) {
     this.color = color;
     return this;
   }
@@ -94,7 +96,7 @@ public class ArrayOfInlineAllOfArrayAllofDogPropertyInner {
     return color;
   }
 
-  public void setColor(String color) {
+  public void setColor(@javax.annotation.Nullable String color) {
     this.color = color;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java

@@ -55,12 +55,13 @@ import org.openapitools.client.JSON;
 public class ArrayOfNumberOnly {
   public static final String SERIALIZED_NAME_ARRAY_NUMBER = "ArrayNumber";
   @SerializedName(SERIALIZED_NAME_ARRAY_NUMBER)
+  @javax.annotation.Nullable
   private List<BigDecimal> arrayNumber = new ArrayList<>();
 
   public ArrayOfNumberOnly() {
   }
 
-  public ArrayOfNumberOnly arrayNumber(List<BigDecimal> arrayNumber) {
+  public ArrayOfNumberOnly arrayNumber(@javax.annotation.Nullable List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
     return this;
   }
@@ -82,7 +83,7 @@ public class ArrayOfNumberOnly {
     return arrayNumber;
   }
 
-  public void setArrayNumber(List<BigDecimal> arrayNumber) {
+  public void setArrayNumber(@javax.annotation.Nullable List<BigDecimal> arrayNumber) {
     this.arrayNumber = arrayNumber;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ArrayTest.java

@@ -55,20 +55,23 @@ import org.openapitools.client.JSON;
 public class ArrayTest {
   public static final String SERIALIZED_NAME_ARRAY_OF_STRING = "array_of_string";
   @SerializedName(SERIALIZED_NAME_ARRAY_OF_STRING)
+  @javax.annotation.Nullable
   private List<String> arrayOfString = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER = "array_array_of_integer";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_INTEGER)
+  @javax.annotation.Nullable
   private List<List<Long>> arrayArrayOfInteger = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL = "array_array_of_model";
   @SerializedName(SERIALIZED_NAME_ARRAY_ARRAY_OF_MODEL)
+  @javax.annotation.Nullable
   private List<List<ReadOnlyFirst>> arrayArrayOfModel = new ArrayList<>();
 
   public ArrayTest() {
   }
 
-  public ArrayTest arrayOfString(List<String> arrayOfString) {
+  public ArrayTest arrayOfString(@javax.annotation.Nullable List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
     return this;
   }
@@ -90,12 +93,12 @@ public class ArrayTest {
     return arrayOfString;
   }
 
-  public void setArrayOfString(List<String> arrayOfString) {
+  public void setArrayOfString(@javax.annotation.Nullable List<String> arrayOfString) {
     this.arrayOfString = arrayOfString;
   }
 
 
-  public ArrayTest arrayArrayOfInteger(List<List<Long>> arrayArrayOfInteger) {
+  public ArrayTest arrayArrayOfInteger(@javax.annotation.Nullable List<List<Long>> arrayArrayOfInteger) {
     this.arrayArrayOfInteger = arrayArrayOfInteger;
     return this;
   }
@@ -117,12 +120,12 @@ public class ArrayTest {
     return arrayArrayOfInteger;
   }
 
-  public void setArrayArrayOfInteger(List<List<Long>> arrayArrayOfInteger) {
+  public void setArrayArrayOfInteger(@javax.annotation.Nullable List<List<Long>> arrayArrayOfInteger) {
     this.arrayArrayOfInteger = arrayArrayOfInteger;
   }
 
 
-  public ArrayTest arrayArrayOfModel(List<List<ReadOnlyFirst>> arrayArrayOfModel) {
+  public ArrayTest arrayArrayOfModel(@javax.annotation.Nullable List<List<ReadOnlyFirst>> arrayArrayOfModel) {
     this.arrayArrayOfModel = arrayArrayOfModel;
     return this;
   }
@@ -144,7 +147,7 @@ public class ArrayTest {
     return arrayArrayOfModel;
   }
 
-  public void setArrayArrayOfModel(List<List<ReadOnlyFirst>> arrayArrayOfModel) {
+  public void setArrayArrayOfModel(@javax.annotation.Nullable List<List<ReadOnlyFirst>> arrayArrayOfModel) {
     this.arrayArrayOfModel = arrayArrayOfModel;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Banana.java

@@ -53,12 +53,13 @@ import org.openapitools.client.JSON;
 public class Banana {
   public static final String SERIALIZED_NAME_LENGTH_CM = "lengthCm";
   @SerializedName(SERIALIZED_NAME_LENGTH_CM)
+  @javax.annotation.Nullable
   private BigDecimal lengthCm;
 
   public Banana() {
   }
 
-  public Banana lengthCm(BigDecimal lengthCm) {
+  public Banana lengthCm(@javax.annotation.Nullable BigDecimal lengthCm) {
     this.lengthCm = lengthCm;
     return this;
   }
@@ -72,7 +73,7 @@ public class Banana {
     return lengthCm;
   }
 
-  public void setLengthCm(BigDecimal lengthCm) {
+  public void setLengthCm(@javax.annotation.Nullable BigDecimal lengthCm) {
     this.lengthCm = lengthCm;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BananaReq.java

@@ -53,16 +53,18 @@ import org.openapitools.client.JSON;
 public class BananaReq {
   public static final String SERIALIZED_NAME_LENGTH_CM = "lengthCm";
   @SerializedName(SERIALIZED_NAME_LENGTH_CM)
+  @javax.annotation.Nonnull
   private BigDecimal lengthCm;
 
   public static final String SERIALIZED_NAME_SWEET = "sweet";
   @SerializedName(SERIALIZED_NAME_SWEET)
+  @javax.annotation.Nullable
   private Boolean sweet;
 
   public BananaReq() {
   }
 
-  public BananaReq lengthCm(BigDecimal lengthCm) {
+  public BananaReq lengthCm(@javax.annotation.Nonnull BigDecimal lengthCm) {
     this.lengthCm = lengthCm;
     return this;
   }
@@ -76,12 +78,12 @@ public class BananaReq {
     return lengthCm;
   }
 
-  public void setLengthCm(BigDecimal lengthCm) {
+  public void setLengthCm(@javax.annotation.Nonnull BigDecimal lengthCm) {
     this.lengthCm = lengthCm;
   }
 
 
-  public BananaReq sweet(Boolean sweet) {
+  public BananaReq sweet(@javax.annotation.Nullable Boolean sweet) {
     this.sweet = sweet;
     return this;
   }
@@ -95,7 +97,7 @@ public class BananaReq {
     return sweet;
   }
 
-  public void setSweet(Boolean sweet) {
+  public void setSweet(@javax.annotation.Nullable Boolean sweet) {
     this.sweet = sweet;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/BasquePig.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class BasquePig {
   public static final String SERIALIZED_NAME_CLASS_NAME = "className";
   @SerializedName(SERIALIZED_NAME_CLASS_NAME)
+  @javax.annotation.Nonnull
   private String className;
 
   public BasquePig() {
   }
 
-  public BasquePig className(String className) {
+  public BasquePig className(@javax.annotation.Nonnull String className) {
     this.className = className;
     return this;
   }
@@ -71,7 +72,7 @@ public class BasquePig {
     return className;
   }
 
-  public void setClassName(String className) {
+  public void setClassName(@javax.annotation.Nonnull String className) {
     this.className = className;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Capitalization.java

@@ -52,32 +52,38 @@ import org.openapitools.client.JSON;
 public class Capitalization {
   public static final String SERIALIZED_NAME_SMALL_CAMEL = "smallCamel";
   @SerializedName(SERIALIZED_NAME_SMALL_CAMEL)
+  @javax.annotation.Nullable
   private String smallCamel;
 
   public static final String SERIALIZED_NAME_CAPITAL_CAMEL = "CapitalCamel";
   @SerializedName(SERIALIZED_NAME_CAPITAL_CAMEL)
+  @javax.annotation.Nullable
   private String capitalCamel;
 
   public static final String SERIALIZED_NAME_SMALL_SNAKE = "small_Snake";
   @SerializedName(SERIALIZED_NAME_SMALL_SNAKE)
+  @javax.annotation.Nullable
   private String smallSnake;
 
   public static final String SERIALIZED_NAME_CAPITAL_SNAKE = "Capital_Snake";
   @SerializedName(SERIALIZED_NAME_CAPITAL_SNAKE)
+  @javax.annotation.Nullable
   private String capitalSnake;
 
   public static final String SERIALIZED_NAME_SC_A_E_T_H_FLOW_POINTS = "SCA_ETH_Flow_Points";
   @SerializedName(SERIALIZED_NAME_SC_A_E_T_H_FLOW_POINTS)
+  @javax.annotation.Nullable
   private String scAETHFlowPoints;
 
   public static final String SERIALIZED_NAME_A_T_T_N_A_M_E = "ATT_NAME";
   @SerializedName(SERIALIZED_NAME_A_T_T_N_A_M_E)
+  @javax.annotation.Nullable
   private String ATT_NAME;
 
   public Capitalization() {
   }
 
-  public Capitalization smallCamel(String smallCamel) {
+  public Capitalization smallCamel(@javax.annotation.Nullable String smallCamel) {
     this.smallCamel = smallCamel;
     return this;
   }
@@ -91,12 +97,12 @@ public class Capitalization {
     return smallCamel;
   }
 
-  public void setSmallCamel(String smallCamel) {
+  public void setSmallCamel(@javax.annotation.Nullable String smallCamel) {
     this.smallCamel = smallCamel;
   }
 
 
-  public Capitalization capitalCamel(String capitalCamel) {
+  public Capitalization capitalCamel(@javax.annotation.Nullable String capitalCamel) {
     this.capitalCamel = capitalCamel;
     return this;
   }
@@ -110,12 +116,12 @@ public class Capitalization {
     return capitalCamel;
   }
 
-  public void setCapitalCamel(String capitalCamel) {
+  public void setCapitalCamel(@javax.annotation.Nullable String capitalCamel) {
     this.capitalCamel = capitalCamel;
   }
 
 
-  public Capitalization smallSnake(String smallSnake) {
+  public Capitalization smallSnake(@javax.annotation.Nullable String smallSnake) {
     this.smallSnake = smallSnake;
     return this;
   }
@@ -129,12 +135,12 @@ public class Capitalization {
     return smallSnake;
   }
 
-  public void setSmallSnake(String smallSnake) {
+  public void setSmallSnake(@javax.annotation.Nullable String smallSnake) {
     this.smallSnake = smallSnake;
   }
 
 
-  public Capitalization capitalSnake(String capitalSnake) {
+  public Capitalization capitalSnake(@javax.annotation.Nullable String capitalSnake) {
     this.capitalSnake = capitalSnake;
     return this;
   }
@@ -148,12 +154,12 @@ public class Capitalization {
     return capitalSnake;
   }
 
-  public void setCapitalSnake(String capitalSnake) {
+  public void setCapitalSnake(@javax.annotation.Nullable String capitalSnake) {
     this.capitalSnake = capitalSnake;
   }
 
 
-  public Capitalization scAETHFlowPoints(String scAETHFlowPoints) {
+  public Capitalization scAETHFlowPoints(@javax.annotation.Nullable String scAETHFlowPoints) {
     this.scAETHFlowPoints = scAETHFlowPoints;
     return this;
   }
@@ -167,12 +173,12 @@ public class Capitalization {
     return scAETHFlowPoints;
   }
 
-  public void setScAETHFlowPoints(String scAETHFlowPoints) {
+  public void setScAETHFlowPoints(@javax.annotation.Nullable String scAETHFlowPoints) {
     this.scAETHFlowPoints = scAETHFlowPoints;
   }
 
 
-  public Capitalization ATT_NAME(String ATT_NAME) {
+  public Capitalization ATT_NAME(@javax.annotation.Nullable String ATT_NAME) {
     this.ATT_NAME = ATT_NAME;
     return this;
   }
@@ -186,7 +192,7 @@ public class Capitalization {
     return ATT_NAME;
   }
 
-  public void setATTNAME(String ATT_NAME) {
+  public void setATTNAME(@javax.annotation.Nullable String ATT_NAME) {
     this.ATT_NAME = ATT_NAME;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Cat.java

@@ -54,13 +54,14 @@ import org.openapitools.client.JSON;
 public class Cat extends Animal {
   public static final String SERIALIZED_NAME_DECLAWED = "declawed";
   @SerializedName(SERIALIZED_NAME_DECLAWED)
+  @javax.annotation.Nullable
   private Boolean declawed;
 
   public Cat() {
     this.className = this.getClass().getSimpleName();
   }
 
-  public Cat declawed(Boolean declawed) {
+  public Cat declawed(@javax.annotation.Nullable Boolean declawed) {
     this.declawed = declawed;
     return this;
   }
@@ -74,7 +75,7 @@ public class Cat extends Animal {
     return declawed;
   }
 
-  public void setDeclawed(Boolean declawed) {
+  public void setDeclawed(@javax.annotation.Nullable Boolean declawed) {
     this.declawed = declawed;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Category.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class Category {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name = "default-name";
 
   public Category() {
   }
 
-  public Category id(Long id) {
+  public Category id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -75,12 +77,12 @@ public class Category {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public Category name(String name) {
+  public Category name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -94,7 +96,7 @@ public class Category {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ClassModel.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class ClassModel {
   public static final String SERIALIZED_NAME_PROPERTY_CLASS = "_class";
   @SerializedName(SERIALIZED_NAME_PROPERTY_CLASS)
+  @javax.annotation.Nullable
   private String propertyClass;
 
   public ClassModel() {
   }
 
-  public ClassModel propertyClass(String propertyClass) {
+  public ClassModel propertyClass(@javax.annotation.Nullable String propertyClass) {
     this.propertyClass = propertyClass;
     return this;
   }
@@ -71,7 +72,7 @@ public class ClassModel {
     return propertyClass;
   }
 
-  public void setPropertyClass(String propertyClass) {
+  public void setPropertyClass(@javax.annotation.Nullable String propertyClass) {
     this.propertyClass = propertyClass;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Client.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class Client {
   public static final String SERIALIZED_NAME_CLIENT = "client";
   @SerializedName(SERIALIZED_NAME_CLIENT)
+  @javax.annotation.Nullable
   private String client;
 
   public Client() {
   }
 
-  public Client client(String client) {
+  public Client client(@javax.annotation.Nullable String client) {
     this.client = client;
     return this;
   }
@@ -71,7 +72,7 @@ public class Client {
     return client;
   }
 
-  public void setClient(String client) {
+  public void setClient(@javax.annotation.Nullable String client) {
     this.client = client;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ComplexQuadrilateral.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class ComplexQuadrilateral {
   public static final String SERIALIZED_NAME_SHAPE_TYPE = "shapeType";
   @SerializedName(SERIALIZED_NAME_SHAPE_TYPE)
+  @javax.annotation.Nonnull
   private String shapeType;
 
   public static final String SERIALIZED_NAME_QUADRILATERAL_TYPE = "quadrilateralType";
   @SerializedName(SERIALIZED_NAME_QUADRILATERAL_TYPE)
+  @javax.annotation.Nonnull
   private String quadrilateralType;
 
   public ComplexQuadrilateral() {
   }
 
-  public ComplexQuadrilateral shapeType(String shapeType) {
+  public ComplexQuadrilateral shapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
     return this;
   }
@@ -75,12 +77,12 @@ public class ComplexQuadrilateral {
     return shapeType;
   }
 
-  public void setShapeType(String shapeType) {
+  public void setShapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
   }
 
 
-  public ComplexQuadrilateral quadrilateralType(String quadrilateralType) {
+  public ComplexQuadrilateral quadrilateralType(@javax.annotation.Nonnull String quadrilateralType) {
     this.quadrilateralType = quadrilateralType;
     return this;
   }
@@ -94,7 +96,7 @@ public class ComplexQuadrilateral {
     return quadrilateralType;
   }
 
-  public void setQuadrilateralType(String quadrilateralType) {
+  public void setQuadrilateralType(@javax.annotation.Nonnull String quadrilateralType) {
     this.quadrilateralType = quadrilateralType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DanishPig.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class DanishPig {
   public static final String SERIALIZED_NAME_CLASS_NAME = "className";
   @SerializedName(SERIALIZED_NAME_CLASS_NAME)
+  @javax.annotation.Nonnull
   private String className;
 
   public DanishPig() {
   }
 
-  public DanishPig className(String className) {
+  public DanishPig className(@javax.annotation.Nonnull String className) {
     this.className = className;
     return this;
   }
@@ -71,7 +72,7 @@ public class DanishPig {
     return className;
   }
 
-  public void setClassName(String className) {
+  public void setClassName(@javax.annotation.Nonnull String className) {
     this.className = className;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/DeprecatedObject.java

@@ -54,12 +54,13 @@ import org.openapitools.client.JSON;
 public class DeprecatedObject {
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nullable
   private String name;
 
   public DeprecatedObject() {
   }
 
-  public DeprecatedObject name(String name) {
+  public DeprecatedObject name(@javax.annotation.Nullable String name) {
     this.name = name;
     return this;
   }
@@ -73,7 +74,7 @@ public class DeprecatedObject {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nullable String name) {
     this.name = name;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Dog.java

@@ -53,13 +53,14 @@ import org.openapitools.client.JSON;
 public class Dog extends Animal {
   public static final String SERIALIZED_NAME_BREED = "breed";
   @SerializedName(SERIALIZED_NAME_BREED)
+  @javax.annotation.Nullable
   private String breed;
 
   public Dog() {
     this.className = this.getClass().getSimpleName();
   }
 
-  public Dog breed(String breed) {
+  public Dog breed(@javax.annotation.Nullable String breed) {
     this.breed = breed;
     return this;
   }
@@ -73,7 +74,7 @@ public class Dog extends Animal {
     return breed;
   }
 
-  public void setBreed(String breed) {
+  public void setBreed(@javax.annotation.Nullable String breed) {
     this.breed = breed;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Drawing.java

@@ -59,24 +59,28 @@ import org.openapitools.client.JSON;
 public class Drawing {
   public static final String SERIALIZED_NAME_MAIN_SHAPE = "mainShape";
   @SerializedName(SERIALIZED_NAME_MAIN_SHAPE)
+  @javax.annotation.Nullable
   private Shape mainShape;
 
   public static final String SERIALIZED_NAME_SHAPE_OR_NULL = "shapeOrNull";
   @SerializedName(SERIALIZED_NAME_SHAPE_OR_NULL)
+  @javax.annotation.Nullable
   private ShapeOrNull shapeOrNull;
 
   public static final String SERIALIZED_NAME_NULLABLE_SHAPE = "nullableShape";
   @SerializedName(SERIALIZED_NAME_NULLABLE_SHAPE)
+  @javax.annotation.Nullable
   private NullableShape nullableShape;
 
   public static final String SERIALIZED_NAME_SHAPES = "shapes";
   @SerializedName(SERIALIZED_NAME_SHAPES)
+  @javax.annotation.Nullable
   private List<Shape> shapes = new ArrayList<>();
 
   public Drawing() {
   }
 
-  public Drawing mainShape(Shape mainShape) {
+  public Drawing mainShape(@javax.annotation.Nullable Shape mainShape) {
     this.mainShape = mainShape;
     return this;
   }
@@ -90,12 +94,12 @@ public class Drawing {
     return mainShape;
   }
 
-  public void setMainShape(Shape mainShape) {
+  public void setMainShape(@javax.annotation.Nullable Shape mainShape) {
     this.mainShape = mainShape;
   }
 
 
-  public Drawing shapeOrNull(ShapeOrNull shapeOrNull) {
+  public Drawing shapeOrNull(@javax.annotation.Nullable ShapeOrNull shapeOrNull) {
     this.shapeOrNull = shapeOrNull;
     return this;
   }
@@ -109,12 +113,12 @@ public class Drawing {
     return shapeOrNull;
   }
 
-  public void setShapeOrNull(ShapeOrNull shapeOrNull) {
+  public void setShapeOrNull(@javax.annotation.Nullable ShapeOrNull shapeOrNull) {
     this.shapeOrNull = shapeOrNull;
   }
 
 
-  public Drawing nullableShape(NullableShape nullableShape) {
+  public Drawing nullableShape(@javax.annotation.Nullable NullableShape nullableShape) {
     this.nullableShape = nullableShape;
     return this;
   }
@@ -128,12 +132,12 @@ public class Drawing {
     return nullableShape;
   }
 
-  public void setNullableShape(NullableShape nullableShape) {
+  public void setNullableShape(@javax.annotation.Nullable NullableShape nullableShape) {
     this.nullableShape = nullableShape;
   }
 
 
-  public Drawing shapes(List<Shape> shapes) {
+  public Drawing shapes(@javax.annotation.Nullable List<Shape> shapes) {
     this.shapes = shapes;
     return this;
   }
@@ -155,7 +159,7 @@ public class Drawing {
     return shapes;
   }
 
-  public void setShapes(List<Shape> shapes) {
+  public void setShapes(@javax.annotation.Nullable List<Shape> shapes) {
     this.shapes = shapes;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumArrays.java

@@ -106,6 +106,7 @@ public class EnumArrays {
 
   public static final String SERIALIZED_NAME_JUST_SYMBOL = "just_symbol";
   @SerializedName(SERIALIZED_NAME_JUST_SYMBOL)
+  @javax.annotation.Nullable
   private JustSymbolEnum justSymbol;
 
   /**
@@ -162,12 +163,13 @@ public class EnumArrays {
 
   public static final String SERIALIZED_NAME_ARRAY_ENUM = "array_enum";
   @SerializedName(SERIALIZED_NAME_ARRAY_ENUM)
+  @javax.annotation.Nullable
   private List<ArrayEnumEnum> arrayEnum = new ArrayList<>();
 
   public EnumArrays() {
   }
 
-  public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
+  public EnumArrays justSymbol(@javax.annotation.Nullable JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
     return this;
   }
@@ -181,12 +183,12 @@ public class EnumArrays {
     return justSymbol;
   }
 
-  public void setJustSymbol(JustSymbolEnum justSymbol) {
+  public void setJustSymbol(@javax.annotation.Nullable JustSymbolEnum justSymbol) {
     this.justSymbol = justSymbol;
   }
 
 
-  public EnumArrays arrayEnum(List<ArrayEnumEnum> arrayEnum) {
+  public EnumArrays arrayEnum(@javax.annotation.Nullable List<ArrayEnumEnum> arrayEnum) {
     this.arrayEnum = arrayEnum;
     return this;
   }
@@ -208,7 +210,7 @@ public class EnumArrays {
     return arrayEnum;
   }
 
-  public void setArrayEnum(List<ArrayEnumEnum> arrayEnum) {
+  public void setArrayEnum(@javax.annotation.Nullable List<ArrayEnumEnum> arrayEnum) {
     this.arrayEnum = arrayEnum;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumStringDiscriminator.java

@@ -104,12 +104,13 @@ public class EnumStringDiscriminator {
 
   public static final String SERIALIZED_NAME_ENUM_STR_TYPE = "enum_str_type";
   @SerializedName(SERIALIZED_NAME_ENUM_STR_TYPE)
+  @javax.annotation.Nonnull
   protected EnumStrTypeEnum enumStrType;
 
   public EnumStringDiscriminator() {
   }
 
-  public EnumStringDiscriminator enumStrType(EnumStrTypeEnum enumStrType) {
+  public EnumStringDiscriminator enumStrType(@javax.annotation.Nonnull EnumStrTypeEnum enumStrType) {
     this.enumStrType = enumStrType;
     return this;
   }
@@ -123,7 +124,7 @@ public class EnumStringDiscriminator {
     return enumStrType;
   }
 
-  public void setEnumStrType(EnumStrTypeEnum enumStrType) {
+  public void setEnumStrType(@javax.annotation.Nonnull EnumStrTypeEnum enumStrType) {
     this.enumStrType = enumStrType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EnumTest.java

@@ -111,6 +111,7 @@ public class EnumTest {
 
   public static final String SERIALIZED_NAME_ENUM_STRING = "enum_string";
   @SerializedName(SERIALIZED_NAME_ENUM_STRING)
+  @javax.annotation.Nullable
   private EnumStringEnum enumString;
 
   /**
@@ -169,6 +170,7 @@ public class EnumTest {
 
   public static final String SERIALIZED_NAME_ENUM_STRING_REQUIRED = "enum_string_required";
   @SerializedName(SERIALIZED_NAME_ENUM_STRING_REQUIRED)
+  @javax.annotation.Nonnull
   private EnumStringRequiredEnum enumStringRequired;
 
   /**
@@ -225,6 +227,7 @@ public class EnumTest {
 
   public static final String SERIALIZED_NAME_ENUM_INTEGER = "enum_integer";
   @SerializedName(SERIALIZED_NAME_ENUM_INTEGER)
+  @javax.annotation.Nullable
   private EnumIntegerEnum enumInteger;
 
   /**
@@ -281,6 +284,7 @@ public class EnumTest {
 
   public static final String SERIALIZED_NAME_ENUM_INTEGER_ONLY = "enum_integer_only";
   @SerializedName(SERIALIZED_NAME_ENUM_INTEGER_ONLY)
+  @javax.annotation.Nullable
   private EnumIntegerOnlyEnum enumIntegerOnly;
 
   /**
@@ -337,28 +341,33 @@ public class EnumTest {
 
   public static final String SERIALIZED_NAME_ENUM_NUMBER = "enum_number";
   @SerializedName(SERIALIZED_NAME_ENUM_NUMBER)
+  @javax.annotation.Nullable
   private EnumNumberEnum enumNumber;
 
   public static final String SERIALIZED_NAME_OUTER_ENUM = "outerEnum";
   @SerializedName(SERIALIZED_NAME_OUTER_ENUM)
+  @javax.annotation.Nullable
   private OuterEnum outerEnum;
 
   public static final String SERIALIZED_NAME_OUTER_ENUM_INTEGER = "outerEnumInteger";
   @SerializedName(SERIALIZED_NAME_OUTER_ENUM_INTEGER)
+  @javax.annotation.Nullable
   private OuterEnumInteger outerEnumInteger;
 
   public static final String SERIALIZED_NAME_OUTER_ENUM_DEFAULT_VALUE = "outerEnumDefaultValue";
   @SerializedName(SERIALIZED_NAME_OUTER_ENUM_DEFAULT_VALUE)
+  @javax.annotation.Nullable
   private OuterEnumDefaultValue outerEnumDefaultValue = OuterEnumDefaultValue.PLACED;
 
   public static final String SERIALIZED_NAME_OUTER_ENUM_INTEGER_DEFAULT_VALUE = "outerEnumIntegerDefaultValue";
   @SerializedName(SERIALIZED_NAME_OUTER_ENUM_INTEGER_DEFAULT_VALUE)
+  @javax.annotation.Nullable
   private OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue = OuterEnumIntegerDefaultValue.NUMBER_0;
 
   public EnumTest() {
   }
 
-  public EnumTest enumString(EnumStringEnum enumString) {
+  public EnumTest enumString(@javax.annotation.Nullable EnumStringEnum enumString) {
     this.enumString = enumString;
     return this;
   }
@@ -372,12 +381,12 @@ public class EnumTest {
     return enumString;
   }
 
-  public void setEnumString(EnumStringEnum enumString) {
+  public void setEnumString(@javax.annotation.Nullable EnumStringEnum enumString) {
     this.enumString = enumString;
   }
 
 
-  public EnumTest enumStringRequired(EnumStringRequiredEnum enumStringRequired) {
+  public EnumTest enumStringRequired(@javax.annotation.Nonnull EnumStringRequiredEnum enumStringRequired) {
     this.enumStringRequired = enumStringRequired;
     return this;
   }
@@ -391,12 +400,12 @@ public class EnumTest {
     return enumStringRequired;
   }
 
-  public void setEnumStringRequired(EnumStringRequiredEnum enumStringRequired) {
+  public void setEnumStringRequired(@javax.annotation.Nonnull EnumStringRequiredEnum enumStringRequired) {
     this.enumStringRequired = enumStringRequired;
   }
 
 
-  public EnumTest enumInteger(EnumIntegerEnum enumInteger) {
+  public EnumTest enumInteger(@javax.annotation.Nullable EnumIntegerEnum enumInteger) {
     this.enumInteger = enumInteger;
     return this;
   }
@@ -410,12 +419,12 @@ public class EnumTest {
     return enumInteger;
   }
 
-  public void setEnumInteger(EnumIntegerEnum enumInteger) {
+  public void setEnumInteger(@javax.annotation.Nullable EnumIntegerEnum enumInteger) {
     this.enumInteger = enumInteger;
   }
 
 
-  public EnumTest enumIntegerOnly(EnumIntegerOnlyEnum enumIntegerOnly) {
+  public EnumTest enumIntegerOnly(@javax.annotation.Nullable EnumIntegerOnlyEnum enumIntegerOnly) {
     this.enumIntegerOnly = enumIntegerOnly;
     return this;
   }
@@ -429,12 +438,12 @@ public class EnumTest {
     return enumIntegerOnly;
   }
 
-  public void setEnumIntegerOnly(EnumIntegerOnlyEnum enumIntegerOnly) {
+  public void setEnumIntegerOnly(@javax.annotation.Nullable EnumIntegerOnlyEnum enumIntegerOnly) {
     this.enumIntegerOnly = enumIntegerOnly;
   }
 
 
-  public EnumTest enumNumber(EnumNumberEnum enumNumber) {
+  public EnumTest enumNumber(@javax.annotation.Nullable EnumNumberEnum enumNumber) {
     this.enumNumber = enumNumber;
     return this;
   }
@@ -448,12 +457,12 @@ public class EnumTest {
     return enumNumber;
   }
 
-  public void setEnumNumber(EnumNumberEnum enumNumber) {
+  public void setEnumNumber(@javax.annotation.Nullable EnumNumberEnum enumNumber) {
     this.enumNumber = enumNumber;
   }
 
 
-  public EnumTest outerEnum(OuterEnum outerEnum) {
+  public EnumTest outerEnum(@javax.annotation.Nullable OuterEnum outerEnum) {
     this.outerEnum = outerEnum;
     return this;
   }
@@ -467,12 +476,12 @@ public class EnumTest {
     return outerEnum;
   }
 
-  public void setOuterEnum(OuterEnum outerEnum) {
+  public void setOuterEnum(@javax.annotation.Nullable OuterEnum outerEnum) {
     this.outerEnum = outerEnum;
   }
 
 
-  public EnumTest outerEnumInteger(OuterEnumInteger outerEnumInteger) {
+  public EnumTest outerEnumInteger(@javax.annotation.Nullable OuterEnumInteger outerEnumInteger) {
     this.outerEnumInteger = outerEnumInteger;
     return this;
   }
@@ -486,12 +495,12 @@ public class EnumTest {
     return outerEnumInteger;
   }
 
-  public void setOuterEnumInteger(OuterEnumInteger outerEnumInteger) {
+  public void setOuterEnumInteger(@javax.annotation.Nullable OuterEnumInteger outerEnumInteger) {
     this.outerEnumInteger = outerEnumInteger;
   }
 
 
-  public EnumTest outerEnumDefaultValue(OuterEnumDefaultValue outerEnumDefaultValue) {
+  public EnumTest outerEnumDefaultValue(@javax.annotation.Nullable OuterEnumDefaultValue outerEnumDefaultValue) {
     this.outerEnumDefaultValue = outerEnumDefaultValue;
     return this;
   }
@@ -505,12 +514,12 @@ public class EnumTest {
     return outerEnumDefaultValue;
   }
 
-  public void setOuterEnumDefaultValue(OuterEnumDefaultValue outerEnumDefaultValue) {
+  public void setOuterEnumDefaultValue(@javax.annotation.Nullable OuterEnumDefaultValue outerEnumDefaultValue) {
     this.outerEnumDefaultValue = outerEnumDefaultValue;
   }
 
 
-  public EnumTest outerEnumIntegerDefaultValue(OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue) {
+  public EnumTest outerEnumIntegerDefaultValue(@javax.annotation.Nullable OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue) {
     this.outerEnumIntegerDefaultValue = outerEnumIntegerDefaultValue;
     return this;
   }
@@ -524,7 +533,7 @@ public class EnumTest {
     return outerEnumIntegerDefaultValue;
   }
 
-  public void setOuterEnumIntegerDefaultValue(OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue) {
+  public void setOuterEnumIntegerDefaultValue(@javax.annotation.Nullable OuterEnumIntegerDefaultValue outerEnumIntegerDefaultValue) {
     this.outerEnumIntegerDefaultValue = outerEnumIntegerDefaultValue;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/EquilateralTriangle.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class EquilateralTriangle {
   public static final String SERIALIZED_NAME_SHAPE_TYPE = "shapeType";
   @SerializedName(SERIALIZED_NAME_SHAPE_TYPE)
+  @javax.annotation.Nonnull
   private String shapeType;
 
   public static final String SERIALIZED_NAME_TRIANGLE_TYPE = "triangleType";
   @SerializedName(SERIALIZED_NAME_TRIANGLE_TYPE)
+  @javax.annotation.Nonnull
   private String triangleType;
 
   public EquilateralTriangle() {
   }
 
-  public EquilateralTriangle shapeType(String shapeType) {
+  public EquilateralTriangle shapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
     return this;
   }
@@ -75,12 +77,12 @@ public class EquilateralTriangle {
     return shapeType;
   }
 
-  public void setShapeType(String shapeType) {
+  public void setShapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
   }
 
 
-  public EquilateralTriangle triangleType(String triangleType) {
+  public EquilateralTriangle triangleType(@javax.annotation.Nonnull String triangleType) {
     this.triangleType = triangleType;
     return this;
   }
@@ -94,7 +96,7 @@ public class EquilateralTriangle {
     return triangleType;
   }
 
-  public void setTriangleType(String triangleType) {
+  public void setTriangleType(@javax.annotation.Nonnull String triangleType) {
     this.triangleType = triangleType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java

@@ -55,16 +55,18 @@ import org.openapitools.client.JSON;
 public class FileSchemaTestClass {
   public static final String SERIALIZED_NAME_FILE = "file";
   @SerializedName(SERIALIZED_NAME_FILE)
+  @javax.annotation.Nullable
   private ModelFile _file;
 
   public static final String SERIALIZED_NAME_FILES = "files";
   @SerializedName(SERIALIZED_NAME_FILES)
+  @javax.annotation.Nullable
   private List<ModelFile> files = new ArrayList<>();
 
   public FileSchemaTestClass() {
   }
 
-  public FileSchemaTestClass _file(ModelFile _file) {
+  public FileSchemaTestClass _file(@javax.annotation.Nullable ModelFile _file) {
     this._file = _file;
     return this;
   }
@@ -78,12 +80,12 @@ public class FileSchemaTestClass {
     return _file;
   }
 
-  public void setFile(ModelFile _file) {
+  public void setFile(@javax.annotation.Nullable ModelFile _file) {
     this._file = _file;
   }
 
 
-  public FileSchemaTestClass files(List<ModelFile> files) {
+  public FileSchemaTestClass files(@javax.annotation.Nullable List<ModelFile> files) {
     this.files = files;
     return this;
   }
@@ -105,7 +107,7 @@ public class FileSchemaTestClass {
     return files;
   }
 
-  public void setFiles(List<ModelFile> files) {
+  public void setFiles(@javax.annotation.Nullable List<ModelFile> files) {
     this.files = files;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Foo.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class Foo {
   public static final String SERIALIZED_NAME_BAR = "bar";
   @SerializedName(SERIALIZED_NAME_BAR)
+  @javax.annotation.Nullable
   private String bar = "bar";
 
   public Foo() {
   }
 
-  public Foo bar(String bar) {
+  public Foo bar(@javax.annotation.Nullable String bar) {
     this.bar = bar;
     return this;
   }
@@ -71,7 +72,7 @@ public class Foo {
     return bar;
   }
 
-  public void setBar(String bar) {
+  public void setBar(@javax.annotation.Nullable String bar) {
     this.bar = bar;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FooGetDefaultResponse.java

@@ -53,12 +53,13 @@ import org.openapitools.client.JSON;
 public class FooGetDefaultResponse {
   public static final String SERIALIZED_NAME_STRING = "string";
   @SerializedName(SERIALIZED_NAME_STRING)
+  @javax.annotation.Nullable
   private Foo string;
 
   public FooGetDefaultResponse() {
   }
 
-  public FooGetDefaultResponse string(Foo string) {
+  public FooGetDefaultResponse string(@javax.annotation.Nullable Foo string) {
     this.string = string;
     return this;
   }
@@ -72,7 +73,7 @@ public class FooGetDefaultResponse {
     return string;
   }
 
-  public void setString(Foo string) {
+  public void setString(@javax.annotation.Nullable Foo string) {
     this.string = string;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FormatTest.java

@@ -57,76 +57,93 @@ import org.openapitools.client.JSON;
 public class FormatTest {
   public static final String SERIALIZED_NAME_INTEGER = "integer";
   @SerializedName(SERIALIZED_NAME_INTEGER)
+  @javax.annotation.Nullable
   private Integer integer;
 
   public static final String SERIALIZED_NAME_INT32 = "int32";
   @SerializedName(SERIALIZED_NAME_INT32)
+  @javax.annotation.Nullable
   private Integer int32;
 
   public static final String SERIALIZED_NAME_INT64 = "int64";
   @SerializedName(SERIALIZED_NAME_INT64)
+  @javax.annotation.Nullable
   private Long int64;
 
   public static final String SERIALIZED_NAME_NUMBER = "number";
   @SerializedName(SERIALIZED_NAME_NUMBER)
+  @javax.annotation.Nonnull
   private BigDecimal number;
 
   public static final String SERIALIZED_NAME_FLOAT = "float";
   @SerializedName(SERIALIZED_NAME_FLOAT)
+  @javax.annotation.Nullable
   private Float _float;
 
   public static final String SERIALIZED_NAME_DOUBLE = "double";
   @SerializedName(SERIALIZED_NAME_DOUBLE)
+  @javax.annotation.Nullable
   private Double _double;
 
   public static final String SERIALIZED_NAME_DECIMAL = "decimal";
   @SerializedName(SERIALIZED_NAME_DECIMAL)
+  @javax.annotation.Nullable
   private BigDecimal decimal;
 
   public static final String SERIALIZED_NAME_STRING = "string";
   @SerializedName(SERIALIZED_NAME_STRING)
+  @javax.annotation.Nullable
   private String string;
 
   public static final String SERIALIZED_NAME_BYTE = "byte";
   @SerializedName(SERIALIZED_NAME_BYTE)
+  @javax.annotation.Nonnull
   private byte[] _byte;
 
   public static final String SERIALIZED_NAME_BINARY = "binary";
   @SerializedName(SERIALIZED_NAME_BINARY)
+  @javax.annotation.Nullable
   private File binary;
 
   public static final String SERIALIZED_NAME_DATE = "date";
   @SerializedName(SERIALIZED_NAME_DATE)
+  @javax.annotation.Nonnull
   private LocalDate date;
 
   public static final String SERIALIZED_NAME_DATE_TIME = "dateTime";
   @SerializedName(SERIALIZED_NAME_DATE_TIME)
+  @javax.annotation.Nullable
   private OffsetDateTime dateTime;
 
   public static final String SERIALIZED_NAME_UUID = "uuid";
   @SerializedName(SERIALIZED_NAME_UUID)
+  @javax.annotation.Nullable
   private UUID uuid;
 
   public static final String SERIALIZED_NAME_UUID_WITH_DEFAULT = "uuid_with_default";
   @SerializedName(SERIALIZED_NAME_UUID_WITH_DEFAULT)
+  @javax.annotation.Nullable
   private UUID uuidWithDefault = UUID.fromString("11111111-206d-4f12-9f12-3d1e525a8e84");
 
   public static final String SERIALIZED_NAME_PASSWORD = "password";
   @SerializedName(SERIALIZED_NAME_PASSWORD)
+  @javax.annotation.Nonnull
   private String password;
 
   public static final String SERIALIZED_NAME_PATTERN_WITH_DIGITS = "pattern_with_digits";
   @SerializedName(SERIALIZED_NAME_PATTERN_WITH_DIGITS)
+  @javax.annotation.Nullable
   private String patternWithDigits;
 
   public static final String SERIALIZED_NAME_PATTERN_WITH_DIGITS_AND_DELIMITER = "pattern_with_digits_and_delimiter";
   @SerializedName(SERIALIZED_NAME_PATTERN_WITH_DIGITS_AND_DELIMITER)
+  @javax.annotation.Nullable
   private String patternWithDigitsAndDelimiter;
 
   public FormatTest() {
   }
 
-  public FormatTest integer(Integer integer) {
+  public FormatTest integer(@javax.annotation.Nullable Integer integer) {
     this.integer = integer;
     return this;
   }
@@ -142,12 +159,12 @@ public class FormatTest {
     return integer;
   }
 
-  public void setInteger(Integer integer) {
+  public void setInteger(@javax.annotation.Nullable Integer integer) {
     this.integer = integer;
   }
 
 
-  public FormatTest int32(Integer int32) {
+  public FormatTest int32(@javax.annotation.Nullable Integer int32) {
     this.int32 = int32;
     return this;
   }
@@ -163,12 +180,12 @@ public class FormatTest {
     return int32;
   }
 
-  public void setInt32(Integer int32) {
+  public void setInt32(@javax.annotation.Nullable Integer int32) {
     this.int32 = int32;
   }
 
 
-  public FormatTest int64(Long int64) {
+  public FormatTest int64(@javax.annotation.Nullable Long int64) {
     this.int64 = int64;
     return this;
   }
@@ -182,12 +199,12 @@ public class FormatTest {
     return int64;
   }
 
-  public void setInt64(Long int64) {
+  public void setInt64(@javax.annotation.Nullable Long int64) {
     this.int64 = int64;
   }
 
 
-  public FormatTest number(BigDecimal number) {
+  public FormatTest number(@javax.annotation.Nonnull BigDecimal number) {
     this.number = number;
     return this;
   }
@@ -203,12 +220,12 @@ public class FormatTest {
     return number;
   }
 
-  public void setNumber(BigDecimal number) {
+  public void setNumber(@javax.annotation.Nonnull BigDecimal number) {
     this.number = number;
   }
 
 
-  public FormatTest _float(Float _float) {
+  public FormatTest _float(@javax.annotation.Nullable Float _float) {
     this._float = _float;
     return this;
   }
@@ -224,12 +241,12 @@ public class FormatTest {
     return _float;
   }
 
-  public void setFloat(Float _float) {
+  public void setFloat(@javax.annotation.Nullable Float _float) {
     this._float = _float;
   }
 
 
-  public FormatTest _double(Double _double) {
+  public FormatTest _double(@javax.annotation.Nullable Double _double) {
     this._double = _double;
     return this;
   }
@@ -245,12 +262,12 @@ public class FormatTest {
     return _double;
   }
 
-  public void setDouble(Double _double) {
+  public void setDouble(@javax.annotation.Nullable Double _double) {
     this._double = _double;
   }
 
 
-  public FormatTest decimal(BigDecimal decimal) {
+  public FormatTest decimal(@javax.annotation.Nullable BigDecimal decimal) {
     this.decimal = decimal;
     return this;
   }
@@ -264,12 +281,12 @@ public class FormatTest {
     return decimal;
   }
 
-  public void setDecimal(BigDecimal decimal) {
+  public void setDecimal(@javax.annotation.Nullable BigDecimal decimal) {
     this.decimal = decimal;
   }
 
 
-  public FormatTest string(String string) {
+  public FormatTest string(@javax.annotation.Nullable String string) {
     this.string = string;
     return this;
   }
@@ -283,12 +300,12 @@ public class FormatTest {
     return string;
   }
 
-  public void setString(String string) {
+  public void setString(@javax.annotation.Nullable String string) {
     this.string = string;
   }
 
 
-  public FormatTest _byte(byte[] _byte) {
+  public FormatTest _byte(@javax.annotation.Nonnull byte[] _byte) {
     this._byte = _byte;
     return this;
   }
@@ -302,12 +319,12 @@ public class FormatTest {
     return _byte;
   }
 
-  public void setByte(byte[] _byte) {
+  public void setByte(@javax.annotation.Nonnull byte[] _byte) {
     this._byte = _byte;
   }
 
 
-  public FormatTest binary(File binary) {
+  public FormatTest binary(@javax.annotation.Nullable File binary) {
     this.binary = binary;
     return this;
   }
@@ -321,12 +338,12 @@ public class FormatTest {
     return binary;
   }
 
-  public void setBinary(File binary) {
+  public void setBinary(@javax.annotation.Nullable File binary) {
     this.binary = binary;
   }
 
 
-  public FormatTest date(LocalDate date) {
+  public FormatTest date(@javax.annotation.Nonnull LocalDate date) {
     this.date = date;
     return this;
   }
@@ -340,12 +357,12 @@ public class FormatTest {
     return date;
   }
 
-  public void setDate(LocalDate date) {
+  public void setDate(@javax.annotation.Nonnull LocalDate date) {
     this.date = date;
   }
 
 
-  public FormatTest dateTime(OffsetDateTime dateTime) {
+  public FormatTest dateTime(@javax.annotation.Nullable OffsetDateTime dateTime) {
     this.dateTime = dateTime;
     return this;
   }
@@ -359,12 +376,12 @@ public class FormatTest {
     return dateTime;
   }
 
-  public void setDateTime(OffsetDateTime dateTime) {
+  public void setDateTime(@javax.annotation.Nullable OffsetDateTime dateTime) {
     this.dateTime = dateTime;
   }
 
 
-  public FormatTest uuid(UUID uuid) {
+  public FormatTest uuid(@javax.annotation.Nullable UUID uuid) {
     this.uuid = uuid;
     return this;
   }
@@ -378,12 +395,12 @@ public class FormatTest {
     return uuid;
   }
 
-  public void setUuid(UUID uuid) {
+  public void setUuid(@javax.annotation.Nullable UUID uuid) {
     this.uuid = uuid;
   }
 
 
-  public FormatTest uuidWithDefault(UUID uuidWithDefault) {
+  public FormatTest uuidWithDefault(@javax.annotation.Nullable UUID uuidWithDefault) {
     this.uuidWithDefault = uuidWithDefault;
     return this;
   }
@@ -397,12 +414,12 @@ public class FormatTest {
     return uuidWithDefault;
   }
 
-  public void setUuidWithDefault(UUID uuidWithDefault) {
+  public void setUuidWithDefault(@javax.annotation.Nullable UUID uuidWithDefault) {
     this.uuidWithDefault = uuidWithDefault;
   }
 
 
-  public FormatTest password(String password) {
+  public FormatTest password(@javax.annotation.Nonnull String password) {
     this.password = password;
     return this;
   }
@@ -416,12 +433,12 @@ public class FormatTest {
     return password;
   }
 
-  public void setPassword(String password) {
+  public void setPassword(@javax.annotation.Nonnull String password) {
     this.password = password;
   }
 
 
-  public FormatTest patternWithDigits(String patternWithDigits) {
+  public FormatTest patternWithDigits(@javax.annotation.Nullable String patternWithDigits) {
     this.patternWithDigits = patternWithDigits;
     return this;
   }
@@ -435,12 +452,12 @@ public class FormatTest {
     return patternWithDigits;
   }
 
-  public void setPatternWithDigits(String patternWithDigits) {
+  public void setPatternWithDigits(@javax.annotation.Nullable String patternWithDigits) {
     this.patternWithDigits = patternWithDigits;
   }
 
 
-  public FormatTest patternWithDigitsAndDelimiter(String patternWithDigitsAndDelimiter) {
+  public FormatTest patternWithDigitsAndDelimiter(@javax.annotation.Nullable String patternWithDigitsAndDelimiter) {
     this.patternWithDigitsAndDelimiter = patternWithDigitsAndDelimiter;
     return this;
   }
@@ -454,7 +471,7 @@ public class FormatTest {
     return patternWithDigitsAndDelimiter;
   }
 
-  public void setPatternWithDigitsAndDelimiter(String patternWithDigitsAndDelimiter) {
+  public void setPatternWithDigitsAndDelimiter(@javax.annotation.Nullable String patternWithDigitsAndDelimiter) {
     this.patternWithDigitsAndDelimiter = patternWithDigitsAndDelimiter;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/FreeFormObjectTestClass.java

@@ -53,16 +53,18 @@ import org.openapitools.client.JSON;
 public class FreeFormObjectTestClass {
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nullable
   private String name;
 
   public static final String SERIALIZED_NAME_PROPERTIES = "properties";
   @SerializedName(SERIALIZED_NAME_PROPERTIES)
+  @javax.annotation.Nullable
   private FreeFormObjectTestClassProperties properties;
 
   public FreeFormObjectTestClass() {
   }
 
-  public FreeFormObjectTestClass name(String name) {
+  public FreeFormObjectTestClass name(@javax.annotation.Nullable String name) {
     this.name = name;
     return this;
   }
@@ -76,12 +78,12 @@ public class FreeFormObjectTestClass {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nullable String name) {
     this.name = name;
   }
 
 
-  public FreeFormObjectTestClass properties(FreeFormObjectTestClassProperties properties) {
+  public FreeFormObjectTestClass properties(@javax.annotation.Nullable FreeFormObjectTestClassProperties properties) {
     this.properties = properties;
     return this;
   }
@@ -95,7 +97,7 @@ public class FreeFormObjectTestClass {
     return properties;
   }
 
-  public void setProperties(FreeFormObjectTestClassProperties properties) {
+  public void setProperties(@javax.annotation.Nullable FreeFormObjectTestClassProperties properties) {
     this.properties = properties;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/GrandparentAnimal.java

@@ -52,13 +52,14 @@ import org.openapitools.client.JSON;
 public class GrandparentAnimal {
   public static final String SERIALIZED_NAME_PET_TYPE = "pet_type";
   @SerializedName(SERIALIZED_NAME_PET_TYPE)
+  @javax.annotation.Nonnull
   protected String petType;
 
   public GrandparentAnimal() {
     this.petType = this.getClass().getSimpleName();
   }
 
-  public GrandparentAnimal petType(String petType) {
+  public GrandparentAnimal petType(@javax.annotation.Nonnull String petType) {
     this.petType = petType;
     return this;
   }
@@ -72,7 +73,7 @@ public class GrandparentAnimal {
     return petType;
   }
 
-  public void setPetType(String petType) {
+  public void setPetType(@javax.annotation.Nonnull String petType) {
     this.petType = petType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java

@@ -52,10 +52,12 @@ import org.openapitools.client.JSON;
 public class HasOnlyReadOnly {
   public static final String SERIALIZED_NAME_BAR = "bar";
   @SerializedName(SERIALIZED_NAME_BAR)
+  @javax.annotation.Nullable
   private String bar;
 
   public static final String SERIALIZED_NAME_FOO = "foo";
   @SerializedName(SERIALIZED_NAME_FOO)
+  @javax.annotation.Nullable
   private String foo;
 
   public HasOnlyReadOnly() {

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/HealthCheckResult.java

@@ -53,12 +53,13 @@ import org.openapitools.client.JSON;
 public class HealthCheckResult {
   public static final String SERIALIZED_NAME_NULLABLE_MESSAGE = "NullableMessage";
   @SerializedName(SERIALIZED_NAME_NULLABLE_MESSAGE)
+  @javax.annotation.Nullable
   private String nullableMessage;
 
   public HealthCheckResult() {
   }
 
-  public HealthCheckResult nullableMessage(String nullableMessage) {
+  public HealthCheckResult nullableMessage(@javax.annotation.Nullable String nullableMessage) {
     this.nullableMessage = nullableMessage;
     return this;
   }
@@ -72,7 +73,7 @@ public class HealthCheckResult {
     return nullableMessage;
   }
 
-  public void setNullableMessage(String nullableMessage) {
+  public void setNullableMessage(@javax.annotation.Nullable String nullableMessage) {
     this.nullableMessage = nullableMessage;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/IsoscelesTriangle.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class IsoscelesTriangle {
   public static final String SERIALIZED_NAME_SHAPE_TYPE = "shapeType";
   @SerializedName(SERIALIZED_NAME_SHAPE_TYPE)
+  @javax.annotation.Nonnull
   private String shapeType;
 
   public static final String SERIALIZED_NAME_TRIANGLE_TYPE = "triangleType";
   @SerializedName(SERIALIZED_NAME_TRIANGLE_TYPE)
+  @javax.annotation.Nonnull
   private String triangleType;
 
   public IsoscelesTriangle() {
   }
 
-  public IsoscelesTriangle shapeType(String shapeType) {
+  public IsoscelesTriangle shapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
     return this;
   }
@@ -75,12 +77,12 @@ public class IsoscelesTriangle {
     return shapeType;
   }
 
-  public void setShapeType(String shapeType) {
+  public void setShapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
   }
 
 
-  public IsoscelesTriangle triangleType(String triangleType) {
+  public IsoscelesTriangle triangleType(@javax.annotation.Nonnull String triangleType) {
     this.triangleType = triangleType;
     return this;
   }
@@ -94,7 +96,7 @@ public class IsoscelesTriangle {
     return triangleType;
   }
 
-  public void setTriangleType(String triangleType) {
+  public void setTriangleType(@javax.annotation.Nonnull String triangleType) {
     this.triangleType = triangleType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MapTest.java

@@ -54,6 +54,7 @@ import org.openapitools.client.JSON;
 public class MapTest {
   public static final String SERIALIZED_NAME_MAP_MAP_OF_STRING = "map_map_of_string";
   @SerializedName(SERIALIZED_NAME_MAP_MAP_OF_STRING)
+  @javax.annotation.Nullable
   private Map<String, Map<String, String>> mapMapOfString = new HashMap<>();
 
   /**
@@ -110,20 +111,23 @@ public class MapTest {
 
   public static final String SERIALIZED_NAME_MAP_OF_ENUM_STRING = "map_of_enum_string";
   @SerializedName(SERIALIZED_NAME_MAP_OF_ENUM_STRING)
+  @javax.annotation.Nullable
   private Map<String, InnerEnum> mapOfEnumString = new HashMap<>();
 
   public static final String SERIALIZED_NAME_DIRECT_MAP = "direct_map";
   @SerializedName(SERIALIZED_NAME_DIRECT_MAP)
+  @javax.annotation.Nullable
   private Map<String, Boolean> directMap = new HashMap<>();
 
   public static final String SERIALIZED_NAME_INDIRECT_MAP = "indirect_map";
   @SerializedName(SERIALIZED_NAME_INDIRECT_MAP)
+  @javax.annotation.Nullable
   private Map<String, Boolean> indirectMap = new HashMap<>();
 
   public MapTest() {
   }
 
-  public MapTest mapMapOfString(Map<String, Map<String, String>> mapMapOfString) {
+  public MapTest mapMapOfString(@javax.annotation.Nullable Map<String, Map<String, String>> mapMapOfString) {
     this.mapMapOfString = mapMapOfString;
     return this;
   }
@@ -145,12 +149,12 @@ public class MapTest {
     return mapMapOfString;
   }
 
-  public void setMapMapOfString(Map<String, Map<String, String>> mapMapOfString) {
+  public void setMapMapOfString(@javax.annotation.Nullable Map<String, Map<String, String>> mapMapOfString) {
     this.mapMapOfString = mapMapOfString;
   }
 
 
-  public MapTest mapOfEnumString(Map<String, InnerEnum> mapOfEnumString) {
+  public MapTest mapOfEnumString(@javax.annotation.Nullable Map<String, InnerEnum> mapOfEnumString) {
     this.mapOfEnumString = mapOfEnumString;
     return this;
   }
@@ -172,12 +176,12 @@ public class MapTest {
     return mapOfEnumString;
   }
 
-  public void setMapOfEnumString(Map<String, InnerEnum> mapOfEnumString) {
+  public void setMapOfEnumString(@javax.annotation.Nullable Map<String, InnerEnum> mapOfEnumString) {
     this.mapOfEnumString = mapOfEnumString;
   }
 
 
-  public MapTest directMap(Map<String, Boolean> directMap) {
+  public MapTest directMap(@javax.annotation.Nullable Map<String, Boolean> directMap) {
     this.directMap = directMap;
     return this;
   }
@@ -199,12 +203,12 @@ public class MapTest {
     return directMap;
   }
 
-  public void setDirectMap(Map<String, Boolean> directMap) {
+  public void setDirectMap(@javax.annotation.Nullable Map<String, Boolean> directMap) {
     this.directMap = directMap;
   }
 
 
-  public MapTest indirectMap(Map<String, Boolean> indirectMap) {
+  public MapTest indirectMap(@javax.annotation.Nullable Map<String, Boolean> indirectMap) {
     this.indirectMap = indirectMap;
     return this;
   }
@@ -226,7 +230,7 @@ public class MapTest {
     return indirectMap;
   }
 
-  public void setIndirectMap(Map<String, Boolean> indirectMap) {
+  public void setIndirectMap(@javax.annotation.Nullable Map<String, Boolean> indirectMap) {
     this.indirectMap = indirectMap;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java

@@ -57,20 +57,23 @@ import org.openapitools.client.JSON;
 public class MixedPropertiesAndAdditionalPropertiesClass {
   public static final String SERIALIZED_NAME_UUID = "uuid";
   @SerializedName(SERIALIZED_NAME_UUID)
+  @javax.annotation.Nullable
   private UUID uuid;
 
   public static final String SERIALIZED_NAME_DATE_TIME = "dateTime";
   @SerializedName(SERIALIZED_NAME_DATE_TIME)
+  @javax.annotation.Nullable
   private OffsetDateTime dateTime;
 
   public static final String SERIALIZED_NAME_MAP = "map";
   @SerializedName(SERIALIZED_NAME_MAP)
+  @javax.annotation.Nullable
   private Map<String, Animal> map = new HashMap<>();
 
   public MixedPropertiesAndAdditionalPropertiesClass() {
   }
 
-  public MixedPropertiesAndAdditionalPropertiesClass uuid(UUID uuid) {
+  public MixedPropertiesAndAdditionalPropertiesClass uuid(@javax.annotation.Nullable UUID uuid) {
     this.uuid = uuid;
     return this;
   }
@@ -84,12 +87,12 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
     return uuid;
   }
 
-  public void setUuid(UUID uuid) {
+  public void setUuid(@javax.annotation.Nullable UUID uuid) {
     this.uuid = uuid;
   }
 
 
-  public MixedPropertiesAndAdditionalPropertiesClass dateTime(OffsetDateTime dateTime) {
+  public MixedPropertiesAndAdditionalPropertiesClass dateTime(@javax.annotation.Nullable OffsetDateTime dateTime) {
     this.dateTime = dateTime;
     return this;
   }
@@ -103,12 +106,12 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
     return dateTime;
   }
 
-  public void setDateTime(OffsetDateTime dateTime) {
+  public void setDateTime(@javax.annotation.Nullable OffsetDateTime dateTime) {
     this.dateTime = dateTime;
   }
 
 
-  public MixedPropertiesAndAdditionalPropertiesClass map(Map<String, Animal> map) {
+  public MixedPropertiesAndAdditionalPropertiesClass map(@javax.annotation.Nullable Map<String, Animal> map) {
     this.map = map;
     return this;
   }
@@ -130,7 +133,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
     return map;
   }
 
-  public void setMap(Map<String, Animal> map) {
+  public void setMap(@javax.annotation.Nullable Map<String, Animal> map) {
     this.map = map;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Model200Response.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class Model200Response {
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nullable
   private Integer name;
 
   public static final String SERIALIZED_NAME_PROPERTY_CLASS = "class";
   @SerializedName(SERIALIZED_NAME_PROPERTY_CLASS)
+  @javax.annotation.Nullable
   private String propertyClass;
 
   public Model200Response() {
   }
 
-  public Model200Response name(Integer name) {
+  public Model200Response name(@javax.annotation.Nullable Integer name) {
     this.name = name;
     return this;
   }
@@ -75,12 +77,12 @@ public class Model200Response {
     return name;
   }
 
-  public void setName(Integer name) {
+  public void setName(@javax.annotation.Nullable Integer name) {
     this.name = name;
   }
 
 
-  public Model200Response propertyClass(String propertyClass) {
+  public Model200Response propertyClass(@javax.annotation.Nullable String propertyClass) {
     this.propertyClass = propertyClass;
     return this;
   }
@@ -94,7 +96,7 @@ public class Model200Response {
     return propertyClass;
   }
 
-  public void setPropertyClass(String propertyClass) {
+  public void setPropertyClass(@javax.annotation.Nullable String propertyClass) {
     this.propertyClass = propertyClass;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelApiResponse.java

@@ -52,20 +52,23 @@ import org.openapitools.client.JSON;
 public class ModelApiResponse {
   public static final String SERIALIZED_NAME_CODE = "code";
   @SerializedName(SERIALIZED_NAME_CODE)
+  @javax.annotation.Nullable
   private Integer code;
 
   public static final String SERIALIZED_NAME_TYPE = "type";
   @SerializedName(SERIALIZED_NAME_TYPE)
+  @javax.annotation.Nullable
   private String type;
 
   public static final String SERIALIZED_NAME_MESSAGE = "message";
   @SerializedName(SERIALIZED_NAME_MESSAGE)
+  @javax.annotation.Nullable
   private String message;
 
   public ModelApiResponse() {
   }
 
-  public ModelApiResponse code(Integer code) {
+  public ModelApiResponse code(@javax.annotation.Nullable Integer code) {
     this.code = code;
     return this;
   }
@@ -79,12 +82,12 @@ public class ModelApiResponse {
     return code;
   }
 
-  public void setCode(Integer code) {
+  public void setCode(@javax.annotation.Nullable Integer code) {
     this.code = code;
   }
 
 
-  public ModelApiResponse type(String type) {
+  public ModelApiResponse type(@javax.annotation.Nullable String type) {
     this.type = type;
     return this;
   }
@@ -98,12 +101,12 @@ public class ModelApiResponse {
     return type;
   }
 
-  public void setType(String type) {
+  public void setType(@javax.annotation.Nullable String type) {
     this.type = type;
   }
 
 
-  public ModelApiResponse message(String message) {
+  public ModelApiResponse message(@javax.annotation.Nullable String message) {
     this.message = message;
     return this;
   }
@@ -117,7 +120,7 @@ public class ModelApiResponse {
     return message;
   }
 
-  public void setMessage(String message) {
+  public void setMessage(@javax.annotation.Nullable String message) {
     this.message = message;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelFile.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class ModelFile {
   public static final String SERIALIZED_NAME_SOURCE_U_R_I = "sourceURI";
   @SerializedName(SERIALIZED_NAME_SOURCE_U_R_I)
+  @javax.annotation.Nullable
   private String sourceURI;
 
   public ModelFile() {
   }
 
-  public ModelFile sourceURI(String sourceURI) {
+  public ModelFile sourceURI(@javax.annotation.Nullable String sourceURI) {
     this.sourceURI = sourceURI;
     return this;
   }
@@ -71,7 +72,7 @@ public class ModelFile {
     return sourceURI;
   }
 
-  public void setSourceURI(String sourceURI) {
+  public void setSourceURI(@javax.annotation.Nullable String sourceURI) {
     this.sourceURI = sourceURI;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelList.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class ModelList {
   public static final String SERIALIZED_NAME_123LIST = "123-list";
   @SerializedName(SERIALIZED_NAME_123LIST)
+  @javax.annotation.Nullable
   private String _123list;
 
   public ModelList() {
   }
 
-  public ModelList _123list(String _123list) {
+  public ModelList _123list(@javax.annotation.Nullable String _123list) {
     this._123list = _123list;
     return this;
   }
@@ -71,7 +72,7 @@ public class ModelList {
     return _123list;
   }
 
-  public void set123list(String _123list) {
+  public void set123list(@javax.annotation.Nullable String _123list) {
     this._123list = _123list;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelReturn.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class ModelReturn {
   public static final String SERIALIZED_NAME_RETURN = "return";
   @SerializedName(SERIALIZED_NAME_RETURN)
+  @javax.annotation.Nullable
   private Integer _return;
 
   public ModelReturn() {
   }
 
-  public ModelReturn _return(Integer _return) {
+  public ModelReturn _return(@javax.annotation.Nullable Integer _return) {
     this._return = _return;
     return this;
   }
@@ -71,7 +72,7 @@ public class ModelReturn {
     return _return;
   }
 
-  public void setReturn(Integer _return) {
+  public void setReturn(@javax.annotation.Nullable Integer _return) {
     this._return = _return;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ModelWithOneOfAnyOfProperties.java

@@ -54,16 +54,18 @@ import org.openapitools.client.JSON;
 public class ModelWithOneOfAnyOfProperties {
   public static final String SERIALIZED_NAME_ONEOF_PROP = "oneof_prop";
   @SerializedName(SERIALIZED_NAME_ONEOF_PROP)
+  @javax.annotation.Nullable
   private ArrayOneOf oneofProp;
 
   public static final String SERIALIZED_NAME_ANYOF_PROP = "anyof_prop";
   @SerializedName(SERIALIZED_NAME_ANYOF_PROP)
+  @javax.annotation.Nullable
   private ArrayAnyOf anyofProp;
 
   public ModelWithOneOfAnyOfProperties() {
   }
 
-  public ModelWithOneOfAnyOfProperties oneofProp(ArrayOneOf oneofProp) {
+  public ModelWithOneOfAnyOfProperties oneofProp(@javax.annotation.Nullable ArrayOneOf oneofProp) {
     this.oneofProp = oneofProp;
     return this;
   }
@@ -77,12 +79,12 @@ public class ModelWithOneOfAnyOfProperties {
     return oneofProp;
   }
 
-  public void setOneofProp(ArrayOneOf oneofProp) {
+  public void setOneofProp(@javax.annotation.Nullable ArrayOneOf oneofProp) {
     this.oneofProp = oneofProp;
   }
 
 
-  public ModelWithOneOfAnyOfProperties anyofProp(ArrayAnyOf anyofProp) {
+  public ModelWithOneOfAnyOfProperties anyofProp(@javax.annotation.Nullable ArrayAnyOf anyofProp) {
     this.anyofProp = anyofProp;
     return this;
   }
@@ -96,7 +98,7 @@ public class ModelWithOneOfAnyOfProperties {
     return anyofProp;
   }
 
-  public void setAnyofProp(ArrayAnyOf anyofProp) {
+  public void setAnyofProp(@javax.annotation.Nullable ArrayAnyOf anyofProp) {
     this.anyofProp = anyofProp;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Name.java

@@ -52,18 +52,22 @@ import org.openapitools.client.JSON;
 public class Name {
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private Integer name;
 
   public static final String SERIALIZED_NAME_SNAKE_CASE = "snake_case";
   @SerializedName(SERIALIZED_NAME_SNAKE_CASE)
+  @javax.annotation.Nullable
   private Integer snakeCase;
 
   public static final String SERIALIZED_NAME_PROPERTY = "property";
   @SerializedName(SERIALIZED_NAME_PROPERTY)
+  @javax.annotation.Nullable
   private String property;
 
   public static final String SERIALIZED_NAME_123NUMBER = "123Number";
   @SerializedName(SERIALIZED_NAME_123NUMBER)
+  @javax.annotation.Nullable
   private Integer _123number;
 
   public Name() {
@@ -78,7 +82,7 @@ public class Name {
     this._123number = _123number;
   }
 
-  public Name name(Integer name) {
+  public Name name(@javax.annotation.Nonnull Integer name) {
     this.name = name;
     return this;
   }
@@ -92,7 +96,7 @@ public class Name {
     return name;
   }
 
-  public void setName(Integer name) {
+  public void setName(@javax.annotation.Nonnull Integer name) {
     this.name = name;
   }
 
@@ -108,7 +112,7 @@ public class Name {
 
 
 
-  public Name property(String property) {
+  public Name property(@javax.annotation.Nullable String property) {
     this.property = property;
     return this;
   }
@@ -122,7 +126,7 @@ public class Name {
     return property;
   }
 
-  public void setProperty(String property) {
+  public void setProperty(@javax.annotation.Nullable String property) {
     this.property = property;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPet.java

@@ -57,34 +57,42 @@ import org.openapitools.client.JSON;
 public class NewPet {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_CATEGORY_INLINE_ALLOF = "category_inline_allof";
   @SerializedName(SERIALIZED_NAME_CATEGORY_INLINE_ALLOF)
+  @javax.annotation.Nullable
   private NewPetCategoryInlineAllof categoryInlineAllof;
 
   public static final String SERIALIZED_NAME_CATEGORY_ALL_OF_REF = "category_allOf_ref";
   @SerializedName(SERIALIZED_NAME_CATEGORY_ALL_OF_REF)
+  @javax.annotation.Nullable
   private Category categoryAllOfRef;
 
   public static final String SERIALIZED_NAME_CATEGORY_ALL_OF_REF_DESCRIPTION = "category_allOf_ref_description";
   @SerializedName(SERIALIZED_NAME_CATEGORY_ALL_OF_REF_DESCRIPTION)
+  @javax.annotation.Nullable
   private Category categoryAllOfRefDescription;
 
   public static final String SERIALIZED_NAME_CATEGORY_ALL_OF_REF_DESCRIPTION_READONLY = "category_allOf_ref_description_readonly";
   @SerializedName(SERIALIZED_NAME_CATEGORY_ALL_OF_REF_DESCRIPTION_READONLY)
+  @javax.annotation.Nullable
   private Category categoryAllOfRefDescriptionReadonly;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name;
 
   public static final String SERIALIZED_NAME_PHOTO_URLS = "photoUrls";
   @SerializedName(SERIALIZED_NAME_PHOTO_URLS)
+  @javax.annotation.Nonnull
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
+  @javax.annotation.Nullable
   private List<Tag> tags = new ArrayList<>();
 
   /**
@@ -143,6 +151,7 @@ public class NewPet {
 
   public static final String SERIALIZED_NAME_STATUS = "status";
   @SerializedName(SERIALIZED_NAME_STATUS)
+  @javax.annotation.Nullable
   private StatusEnum status;
 
   public NewPet() {
@@ -155,7 +164,7 @@ public class NewPet {
     this.categoryAllOfRefDescriptionReadonly = categoryAllOfRefDescriptionReadonly;
   }
 
-  public NewPet id(Long id) {
+  public NewPet id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -169,12 +178,12 @@ public class NewPet {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public NewPet categoryInlineAllof(NewPetCategoryInlineAllof categoryInlineAllof) {
+  public NewPet categoryInlineAllof(@javax.annotation.Nullable NewPetCategoryInlineAllof categoryInlineAllof) {
     this.categoryInlineAllof = categoryInlineAllof;
     return this;
   }
@@ -188,12 +197,12 @@ public class NewPet {
     return categoryInlineAllof;
   }
 
-  public void setCategoryInlineAllof(NewPetCategoryInlineAllof categoryInlineAllof) {
+  public void setCategoryInlineAllof(@javax.annotation.Nullable NewPetCategoryInlineAllof categoryInlineAllof) {
     this.categoryInlineAllof = categoryInlineAllof;
   }
 
 
-  public NewPet categoryAllOfRef(Category categoryAllOfRef) {
+  public NewPet categoryAllOfRef(@javax.annotation.Nullable Category categoryAllOfRef) {
     this.categoryAllOfRef = categoryAllOfRef;
     return this;
   }
@@ -207,12 +216,12 @@ public class NewPet {
     return categoryAllOfRef;
   }
 
-  public void setCategoryAllOfRef(Category categoryAllOfRef) {
+  public void setCategoryAllOfRef(@javax.annotation.Nullable Category categoryAllOfRef) {
     this.categoryAllOfRef = categoryAllOfRef;
   }
 
 
-  public NewPet categoryAllOfRefDescription(Category categoryAllOfRefDescription) {
+  public NewPet categoryAllOfRefDescription(@javax.annotation.Nullable Category categoryAllOfRefDescription) {
     this.categoryAllOfRefDescription = categoryAllOfRefDescription;
     return this;
   }
@@ -226,7 +235,7 @@ public class NewPet {
     return categoryAllOfRefDescription;
   }
 
-  public void setCategoryAllOfRefDescription(Category categoryAllOfRefDescription) {
+  public void setCategoryAllOfRefDescription(@javax.annotation.Nullable Category categoryAllOfRefDescription) {
     this.categoryAllOfRefDescription = categoryAllOfRefDescription;
   }
 
@@ -242,7 +251,7 @@ public class NewPet {
 
 
 
-  public NewPet name(String name) {
+  public NewPet name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -256,12 +265,12 @@ public class NewPet {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public NewPet photoUrls(List<String> photoUrls) {
+  public NewPet photoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
     return this;
   }
@@ -283,12 +292,12 @@ public class NewPet {
     return photoUrls;
   }
 
-  public void setPhotoUrls(List<String> photoUrls) {
+  public void setPhotoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
   }
 
 
-  public NewPet tags(List<Tag> tags) {
+  public NewPet tags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
     return this;
   }
@@ -310,12 +319,12 @@ public class NewPet {
     return tags;
   }
 
-  public void setTags(List<Tag> tags) {
+  public void setTags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
   }
 
 
-  public NewPet status(StatusEnum status) {
+  public NewPet status(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
     return this;
   }
@@ -329,7 +338,7 @@ public class NewPet {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllof.java

@@ -53,20 +53,23 @@ import org.openapitools.client.JSON;
 public class NewPetCategoryInlineAllof {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name = "default-name";
 
   public static final String SERIALIZED_NAME_CATEGORY_TAG = "category_tag";
   @SerializedName(SERIALIZED_NAME_CATEGORY_TAG)
+  @javax.annotation.Nullable
   private NewPetCategoryInlineAllofAllOfCategoryTag categoryTag;
 
   public NewPetCategoryInlineAllof() {
   }
 
-  public NewPetCategoryInlineAllof id(Long id) {
+  public NewPetCategoryInlineAllof id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -80,12 +83,12 @@ public class NewPetCategoryInlineAllof {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public NewPetCategoryInlineAllof name(String name) {
+  public NewPetCategoryInlineAllof name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -99,12 +102,12 @@ public class NewPetCategoryInlineAllof {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public NewPetCategoryInlineAllof categoryTag(NewPetCategoryInlineAllofAllOfCategoryTag categoryTag) {
+  public NewPetCategoryInlineAllof categoryTag(@javax.annotation.Nullable NewPetCategoryInlineAllofAllOfCategoryTag categoryTag) {
     this.categoryTag = categoryTag;
     return this;
   }
@@ -118,7 +121,7 @@ public class NewPetCategoryInlineAllof {
     return categoryTag;
   }
 
-  public void setCategoryTag(NewPetCategoryInlineAllofAllOfCategoryTag categoryTag) {
+  public void setCategoryTag(@javax.annotation.Nullable NewPetCategoryInlineAllofAllOfCategoryTag categoryTag) {
     this.categoryTag = categoryTag;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NewPetCategoryInlineAllofAllOfCategoryTag.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class NewPetCategoryInlineAllofAllOfCategoryTag {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nullable
   private String name;
 
   public NewPetCategoryInlineAllofAllOfCategoryTag() {
   }
 
-  public NewPetCategoryInlineAllofAllOfCategoryTag id(Long id) {
+  public NewPetCategoryInlineAllofAllOfCategoryTag id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -75,12 +77,12 @@ public class NewPetCategoryInlineAllofAllOfCategoryTag {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public NewPetCategoryInlineAllofAllOfCategoryTag name(String name) {
+  public NewPetCategoryInlineAllofAllOfCategoryTag name(@javax.annotation.Nullable String name) {
     this.name = name;
     return this;
   }
@@ -94,7 +96,7 @@ public class NewPetCategoryInlineAllofAllOfCategoryTag {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nullable String name) {
     this.name = name;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NullableClass.java

@@ -60,56 +60,68 @@ import org.openapitools.client.JSON;
 public class NullableClass {
   public static final String SERIALIZED_NAME_INTEGER_PROP = "integer_prop";
   @SerializedName(SERIALIZED_NAME_INTEGER_PROP)
+  @javax.annotation.Nullable
   private Integer integerProp;
 
   public static final String SERIALIZED_NAME_NUMBER_PROP = "number_prop";
   @SerializedName(SERIALIZED_NAME_NUMBER_PROP)
+  @javax.annotation.Nullable
   private BigDecimal numberProp;
 
   public static final String SERIALIZED_NAME_BOOLEAN_PROP = "boolean_prop";
   @SerializedName(SERIALIZED_NAME_BOOLEAN_PROP)
+  @javax.annotation.Nullable
   private Boolean booleanProp;
 
   public static final String SERIALIZED_NAME_STRING_PROP = "string_prop";
   @SerializedName(SERIALIZED_NAME_STRING_PROP)
+  @javax.annotation.Nullable
   private String stringProp;
 
   public static final String SERIALIZED_NAME_DATE_PROP = "date_prop";
   @SerializedName(SERIALIZED_NAME_DATE_PROP)
+  @javax.annotation.Nullable
   private LocalDate dateProp;
 
   public static final String SERIALIZED_NAME_DATETIME_PROP = "datetime_prop";
   @SerializedName(SERIALIZED_NAME_DATETIME_PROP)
+  @javax.annotation.Nullable
   private OffsetDateTime datetimeProp;
 
   public static final String SERIALIZED_NAME_ARRAY_NULLABLE_PROP = "array_nullable_prop";
   @SerializedName(SERIALIZED_NAME_ARRAY_NULLABLE_PROP)
+  @javax.annotation.Nullable
   private List<Object> arrayNullableProp;
 
   public static final String SERIALIZED_NAME_ARRAY_AND_ITEMS_NULLABLE_PROP = "array_and_items_nullable_prop";
   @SerializedName(SERIALIZED_NAME_ARRAY_AND_ITEMS_NULLABLE_PROP)
+  @javax.annotation.Nullable
   private List<Object> arrayAndItemsNullableProp;
 
   public static final String SERIALIZED_NAME_ARRAY_ITEMS_NULLABLE = "array_items_nullable";
   @SerializedName(SERIALIZED_NAME_ARRAY_ITEMS_NULLABLE)
+  @javax.annotation.Nullable
   private List<Object> arrayItemsNullable = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_OBJECT_NULLABLE_PROP = "object_nullable_prop";
   @SerializedName(SERIALIZED_NAME_OBJECT_NULLABLE_PROP)
+  @javax.annotation.Nullable
   private Map<String, Object> objectNullableProp;
 
   public static final String SERIALIZED_NAME_OBJECT_AND_ITEMS_NULLABLE_PROP = "object_and_items_nullable_prop";
   @SerializedName(SERIALIZED_NAME_OBJECT_AND_ITEMS_NULLABLE_PROP)
+  @javax.annotation.Nullable
   private Map<String, Object> objectAndItemsNullableProp;
 
   public static final String SERIALIZED_NAME_OBJECT_ITEMS_NULLABLE = "object_items_nullable";
   @SerializedName(SERIALIZED_NAME_OBJECT_ITEMS_NULLABLE)
+  @javax.annotation.Nullable
   private Map<String, Object> objectItemsNullable = new HashMap<>();
 
   public NullableClass() {
   }
 
-  public NullableClass integerProp(Integer integerProp) {
+  public NullableClass integerProp(@javax.annotation.Nullable Integer integerProp) {
     this.integerProp = integerProp;
     return this;
   }
@@ -123,12 +135,12 @@ public class NullableClass {
     return integerProp;
   }
 
-  public void setIntegerProp(Integer integerProp) {
+  public void setIntegerProp(@javax.annotation.Nullable Integer integerProp) {
     this.integerProp = integerProp;
   }
 
 
-  public NullableClass numberProp(BigDecimal numberProp) {
+  public NullableClass numberProp(@javax.annotation.Nullable BigDecimal numberProp) {
     this.numberProp = numberProp;
     return this;
   }
@@ -142,12 +154,12 @@ public class NullableClass {
     return numberProp;
   }
 
-  public void setNumberProp(BigDecimal numberProp) {
+  public void setNumberProp(@javax.annotation.Nullable BigDecimal numberProp) {
     this.numberProp = numberProp;
   }
 
 
-  public NullableClass booleanProp(Boolean booleanProp) {
+  public NullableClass booleanProp(@javax.annotation.Nullable Boolean booleanProp) {
     this.booleanProp = booleanProp;
     return this;
   }
@@ -161,12 +173,12 @@ public class NullableClass {
     return booleanProp;
   }
 
-  public void setBooleanProp(Boolean booleanProp) {
+  public void setBooleanProp(@javax.annotation.Nullable Boolean booleanProp) {
     this.booleanProp = booleanProp;
   }
 
 
-  public NullableClass stringProp(String stringProp) {
+  public NullableClass stringProp(@javax.annotation.Nullable String stringProp) {
     this.stringProp = stringProp;
     return this;
   }
@@ -180,12 +192,12 @@ public class NullableClass {
     return stringProp;
   }
 
-  public void setStringProp(String stringProp) {
+  public void setStringProp(@javax.annotation.Nullable String stringProp) {
     this.stringProp = stringProp;
   }
 
 
-  public NullableClass dateProp(LocalDate dateProp) {
+  public NullableClass dateProp(@javax.annotation.Nullable LocalDate dateProp) {
     this.dateProp = dateProp;
     return this;
   }
@@ -199,12 +211,12 @@ public class NullableClass {
     return dateProp;
   }
 
-  public void setDateProp(LocalDate dateProp) {
+  public void setDateProp(@javax.annotation.Nullable LocalDate dateProp) {
     this.dateProp = dateProp;
   }
 
 
-  public NullableClass datetimeProp(OffsetDateTime datetimeProp) {
+  public NullableClass datetimeProp(@javax.annotation.Nullable OffsetDateTime datetimeProp) {
     this.datetimeProp = datetimeProp;
     return this;
   }
@@ -218,12 +230,12 @@ public class NullableClass {
     return datetimeProp;
   }
 
-  public void setDatetimeProp(OffsetDateTime datetimeProp) {
+  public void setDatetimeProp(@javax.annotation.Nullable OffsetDateTime datetimeProp) {
     this.datetimeProp = datetimeProp;
   }
 
 
-  public NullableClass arrayNullableProp(List<Object> arrayNullableProp) {
+  public NullableClass arrayNullableProp(@javax.annotation.Nullable List<Object> arrayNullableProp) {
     this.arrayNullableProp = arrayNullableProp;
     return this;
   }
@@ -245,12 +257,12 @@ public class NullableClass {
     return arrayNullableProp;
   }
 
-  public void setArrayNullableProp(List<Object> arrayNullableProp) {
+  public void setArrayNullableProp(@javax.annotation.Nullable List<Object> arrayNullableProp) {
     this.arrayNullableProp = arrayNullableProp;
   }
 
 
-  public NullableClass arrayAndItemsNullableProp(List<Object> arrayAndItemsNullableProp) {
+  public NullableClass arrayAndItemsNullableProp(@javax.annotation.Nullable List<Object> arrayAndItemsNullableProp) {
     this.arrayAndItemsNullableProp = arrayAndItemsNullableProp;
     return this;
   }
@@ -272,12 +284,12 @@ public class NullableClass {
     return arrayAndItemsNullableProp;
   }
 
-  public void setArrayAndItemsNullableProp(List<Object> arrayAndItemsNullableProp) {
+  public void setArrayAndItemsNullableProp(@javax.annotation.Nullable List<Object> arrayAndItemsNullableProp) {
     this.arrayAndItemsNullableProp = arrayAndItemsNullableProp;
   }
 
 
-  public NullableClass arrayItemsNullable(List<Object> arrayItemsNullable) {
+  public NullableClass arrayItemsNullable(@javax.annotation.Nullable List<Object> arrayItemsNullable) {
     this.arrayItemsNullable = arrayItemsNullable;
     return this;
   }
@@ -299,12 +311,12 @@ public class NullableClass {
     return arrayItemsNullable;
   }
 
-  public void setArrayItemsNullable(List<Object> arrayItemsNullable) {
+  public void setArrayItemsNullable(@javax.annotation.Nullable List<Object> arrayItemsNullable) {
     this.arrayItemsNullable = arrayItemsNullable;
   }
 
 
-  public NullableClass objectNullableProp(Map<String, Object> objectNullableProp) {
+  public NullableClass objectNullableProp(@javax.annotation.Nullable Map<String, Object> objectNullableProp) {
     this.objectNullableProp = objectNullableProp;
     return this;
   }
@@ -326,12 +338,12 @@ public class NullableClass {
     return objectNullableProp;
   }
 
-  public void setObjectNullableProp(Map<String, Object> objectNullableProp) {
+  public void setObjectNullableProp(@javax.annotation.Nullable Map<String, Object> objectNullableProp) {
     this.objectNullableProp = objectNullableProp;
   }
 
 
-  public NullableClass objectAndItemsNullableProp(Map<String, Object> objectAndItemsNullableProp) {
+  public NullableClass objectAndItemsNullableProp(@javax.annotation.Nullable Map<String, Object> objectAndItemsNullableProp) {
     this.objectAndItemsNullableProp = objectAndItemsNullableProp;
     return this;
   }
@@ -353,12 +365,12 @@ public class NullableClass {
     return objectAndItemsNullableProp;
   }
 
-  public void setObjectAndItemsNullableProp(Map<String, Object> objectAndItemsNullableProp) {
+  public void setObjectAndItemsNullableProp(@javax.annotation.Nullable Map<String, Object> objectAndItemsNullableProp) {
     this.objectAndItemsNullableProp = objectAndItemsNullableProp;
   }
 
 
-  public NullableClass objectItemsNullable(Map<String, Object> objectItemsNullable) {
+  public NullableClass objectItemsNullable(@javax.annotation.Nullable Map<String, Object> objectItemsNullable) {
     this.objectItemsNullable = objectItemsNullable;
     return this;
   }
@@ -380,7 +392,7 @@ public class NullableClass {
     return objectItemsNullable;
   }
 
-  public void setObjectItemsNullable(Map<String, Object> objectItemsNullable) {
+  public void setObjectItemsNullable(@javax.annotation.Nullable Map<String, Object> objectItemsNullable) {
     this.objectItemsNullable = objectItemsNullable;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/NumberOnly.java

@@ -53,12 +53,13 @@ import org.openapitools.client.JSON;
 public class NumberOnly {
   public static final String SERIALIZED_NAME_JUST_NUMBER = "JustNumber";
   @SerializedName(SERIALIZED_NAME_JUST_NUMBER)
+  @javax.annotation.Nullable
   private BigDecimal justNumber;
 
   public NumberOnly() {
   }
 
-  public NumberOnly justNumber(BigDecimal justNumber) {
+  public NumberOnly justNumber(@javax.annotation.Nullable BigDecimal justNumber) {
     this.justNumber = justNumber;
     return this;
   }
@@ -72,7 +73,7 @@ public class NumberOnly {
     return justNumber;
   }
 
-  public void setJustNumber(BigDecimal justNumber) {
+  public void setJustNumber(@javax.annotation.Nullable BigDecimal justNumber) {
     this.justNumber = justNumber;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ObjectWithDeprecatedFields.java

@@ -56,27 +56,31 @@ import org.openapitools.client.JSON;
 public class ObjectWithDeprecatedFields {
   public static final String SERIALIZED_NAME_UUID = "uuid";
   @SerializedName(SERIALIZED_NAME_UUID)
+  @javax.annotation.Nullable
   private String uuid;
 
   public static final String SERIALIZED_NAME_ID = "id";
   @Deprecated
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private BigDecimal id;
 
   public static final String SERIALIZED_NAME_DEPRECATED_REF = "deprecatedRef";
   @Deprecated
   @SerializedName(SERIALIZED_NAME_DEPRECATED_REF)
+  @javax.annotation.Nullable
   private DeprecatedObject deprecatedRef;
 
   public static final String SERIALIZED_NAME_BARS = "bars";
   @Deprecated
   @SerializedName(SERIALIZED_NAME_BARS)
+  @javax.annotation.Nullable
   private List<String> bars = new ArrayList<>();
 
   public ObjectWithDeprecatedFields() {
   }
 
-  public ObjectWithDeprecatedFields uuid(String uuid) {
+  public ObjectWithDeprecatedFields uuid(@javax.annotation.Nullable String uuid) {
     this.uuid = uuid;
     return this;
   }
@@ -90,13 +94,13 @@ public class ObjectWithDeprecatedFields {
     return uuid;
   }
 
-  public void setUuid(String uuid) {
+  public void setUuid(@javax.annotation.Nullable String uuid) {
     this.uuid = uuid;
   }
 
 
   @Deprecated
-  public ObjectWithDeprecatedFields id(BigDecimal id) {
+  public ObjectWithDeprecatedFields id(@javax.annotation.Nullable BigDecimal id) {
     this.id = id;
     return this;
   }
@@ -113,13 +117,13 @@ public class ObjectWithDeprecatedFields {
   }
 
   @Deprecated
-  public void setId(BigDecimal id) {
+  public void setId(@javax.annotation.Nullable BigDecimal id) {
     this.id = id;
   }
 
 
   @Deprecated
-  public ObjectWithDeprecatedFields deprecatedRef(DeprecatedObject deprecatedRef) {
+  public ObjectWithDeprecatedFields deprecatedRef(@javax.annotation.Nullable DeprecatedObject deprecatedRef) {
     this.deprecatedRef = deprecatedRef;
     return this;
   }
@@ -136,13 +140,13 @@ public class ObjectWithDeprecatedFields {
   }
 
   @Deprecated
-  public void setDeprecatedRef(DeprecatedObject deprecatedRef) {
+  public void setDeprecatedRef(@javax.annotation.Nullable DeprecatedObject deprecatedRef) {
     this.deprecatedRef = deprecatedRef;
   }
 
 
   @Deprecated
-  public ObjectWithDeprecatedFields bars(List<String> bars) {
+  public ObjectWithDeprecatedFields bars(@javax.annotation.Nullable List<String> bars) {
     this.bars = bars;
     return this;
   }
@@ -167,7 +171,7 @@ public class ObjectWithDeprecatedFields {
   }
 
   @Deprecated
-  public void setBars(List<String> bars) {
+  public void setBars(@javax.annotation.Nullable List<String> bars) {
     this.bars = bars;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Order.java

@@ -53,18 +53,22 @@ import org.openapitools.client.JSON;
 public class Order {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_PET_ID = "petId";
   @SerializedName(SERIALIZED_NAME_PET_ID)
+  @javax.annotation.Nullable
   private Long petId;
 
   public static final String SERIALIZED_NAME_QUANTITY = "quantity";
   @SerializedName(SERIALIZED_NAME_QUANTITY)
+  @javax.annotation.Nullable
   private Integer quantity;
 
   public static final String SERIALIZED_NAME_SHIP_DATE = "shipDate";
   @SerializedName(SERIALIZED_NAME_SHIP_DATE)
+  @javax.annotation.Nullable
   private OffsetDateTime shipDate;
 
   /**
@@ -123,16 +127,18 @@ public class Order {
 
   public static final String SERIALIZED_NAME_STATUS = "status";
   @SerializedName(SERIALIZED_NAME_STATUS)
+  @javax.annotation.Nullable
   private StatusEnum status;
 
   public static final String SERIALIZED_NAME_COMPLETE = "complete";
   @SerializedName(SERIALIZED_NAME_COMPLETE)
+  @javax.annotation.Nullable
   private Boolean complete = false;
 
   public Order() {
   }
 
-  public Order id(Long id) {
+  public Order id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -146,12 +152,12 @@ public class Order {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public Order petId(Long petId) {
+  public Order petId(@javax.annotation.Nullable Long petId) {
     this.petId = petId;
     return this;
   }
@@ -165,12 +171,12 @@ public class Order {
     return petId;
   }
 
-  public void setPetId(Long petId) {
+  public void setPetId(@javax.annotation.Nullable Long petId) {
     this.petId = petId;
   }
 
 
-  public Order quantity(Integer quantity) {
+  public Order quantity(@javax.annotation.Nullable Integer quantity) {
     this.quantity = quantity;
     return this;
   }
@@ -184,12 +190,12 @@ public class Order {
     return quantity;
   }
 
-  public void setQuantity(Integer quantity) {
+  public void setQuantity(@javax.annotation.Nullable Integer quantity) {
     this.quantity = quantity;
   }
 
 
-  public Order shipDate(OffsetDateTime shipDate) {
+  public Order shipDate(@javax.annotation.Nullable OffsetDateTime shipDate) {
     this.shipDate = shipDate;
     return this;
   }
@@ -203,12 +209,12 @@ public class Order {
     return shipDate;
   }
 
-  public void setShipDate(OffsetDateTime shipDate) {
+  public void setShipDate(@javax.annotation.Nullable OffsetDateTime shipDate) {
     this.shipDate = shipDate;
   }
 
 
-  public Order status(StatusEnum status) {
+  public Order status(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
     return this;
   }
@@ -222,12 +228,12 @@ public class Order {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
   }
 
 
-  public Order complete(Boolean complete) {
+  public Order complete(@javax.annotation.Nullable Boolean complete) {
     this.complete = complete;
     return this;
   }
@@ -241,7 +247,7 @@ public class Order {
     return complete;
   }
 
-  public void setComplete(Boolean complete) {
+  public void setComplete(@javax.annotation.Nullable Boolean complete) {
     this.complete = complete;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/OuterComposite.java

@@ -53,20 +53,23 @@ import org.openapitools.client.JSON;
 public class OuterComposite {
   public static final String SERIALIZED_NAME_MY_NUMBER = "my_number";
   @SerializedName(SERIALIZED_NAME_MY_NUMBER)
+  @javax.annotation.Nullable
   private BigDecimal myNumber;
 
   public static final String SERIALIZED_NAME_MY_STRING = "my_string";
   @SerializedName(SERIALIZED_NAME_MY_STRING)
+  @javax.annotation.Nullable
   private String myString;
 
   public static final String SERIALIZED_NAME_MY_BOOLEAN = "my_boolean";
   @SerializedName(SERIALIZED_NAME_MY_BOOLEAN)
+  @javax.annotation.Nullable
   private Boolean myBoolean;
 
   public OuterComposite() {
   }
 
-  public OuterComposite myNumber(BigDecimal myNumber) {
+  public OuterComposite myNumber(@javax.annotation.Nullable BigDecimal myNumber) {
     this.myNumber = myNumber;
     return this;
   }
@@ -80,12 +83,12 @@ public class OuterComposite {
     return myNumber;
   }
 
-  public void setMyNumber(BigDecimal myNumber) {
+  public void setMyNumber(@javax.annotation.Nullable BigDecimal myNumber) {
     this.myNumber = myNumber;
   }
 
 
-  public OuterComposite myString(String myString) {
+  public OuterComposite myString(@javax.annotation.Nullable String myString) {
     this.myString = myString;
     return this;
   }
@@ -99,12 +102,12 @@ public class OuterComposite {
     return myString;
   }
 
-  public void setMyString(String myString) {
+  public void setMyString(@javax.annotation.Nullable String myString) {
     this.myString = myString;
   }
 
 
-  public OuterComposite myBoolean(Boolean myBoolean) {
+  public OuterComposite myBoolean(@javax.annotation.Nullable Boolean myBoolean) {
     this.myBoolean = myBoolean;
     return this;
   }
@@ -118,7 +121,7 @@ public class OuterComposite {
     return myBoolean;
   }
 
-  public void setMyBoolean(Boolean myBoolean) {
+  public void setMyBoolean(@javax.annotation.Nullable Boolean myBoolean) {
     this.myBoolean = myBoolean;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Pet.java

@@ -56,22 +56,27 @@ import org.openapitools.client.JSON;
 public class Pet {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_CATEGORY = "category";
   @SerializedName(SERIALIZED_NAME_CATEGORY)
+  @javax.annotation.Nullable
   private Category category;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name;
 
   public static final String SERIALIZED_NAME_PHOTO_URLS = "photoUrls";
   @SerializedName(SERIALIZED_NAME_PHOTO_URLS)
+  @javax.annotation.Nonnull
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
+  @javax.annotation.Nullable
   private List<Tag> tags = new ArrayList<>();
 
   /**
@@ -130,12 +135,13 @@ public class Pet {
 
   public static final String SERIALIZED_NAME_STATUS = "status";
   @SerializedName(SERIALIZED_NAME_STATUS)
+  @javax.annotation.Nullable
   private StatusEnum status;
 
   public Pet() {
   }
 
-  public Pet id(Long id) {
+  public Pet id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -149,12 +155,12 @@ public class Pet {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public Pet category(Category category) {
+  public Pet category(@javax.annotation.Nullable Category category) {
     this.category = category;
     return this;
   }
@@ -168,12 +174,12 @@ public class Pet {
     return category;
   }
 
-  public void setCategory(Category category) {
+  public void setCategory(@javax.annotation.Nullable Category category) {
     this.category = category;
   }
 
 
-  public Pet name(String name) {
+  public Pet name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -187,12 +193,12 @@ public class Pet {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public Pet photoUrls(List<String> photoUrls) {
+  public Pet photoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
     return this;
   }
@@ -214,12 +220,12 @@ public class Pet {
     return photoUrls;
   }
 
-  public void setPhotoUrls(List<String> photoUrls) {
+  public void setPhotoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
   }
 
 
-  public Pet tags(List<Tag> tags) {
+  public Pet tags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
     return this;
   }
@@ -241,12 +247,12 @@ public class Pet {
     return tags;
   }
 
-  public void setTags(List<Tag> tags) {
+  public void setTags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
   }
 
 
-  public Pet status(StatusEnum status) {
+  public Pet status(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
     return this;
   }
@@ -260,7 +266,7 @@ public class Pet {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetComposition.java

@@ -56,22 +56,27 @@ import org.openapitools.client.JSON;
 public class PetComposition {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_CATEGORY = "category";
   @SerializedName(SERIALIZED_NAME_CATEGORY)
+  @javax.annotation.Nullable
   private Category category;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name;
 
   public static final String SERIALIZED_NAME_PHOTO_URLS = "photoUrls";
   @SerializedName(SERIALIZED_NAME_PHOTO_URLS)
+  @javax.annotation.Nonnull
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
+  @javax.annotation.Nullable
   private List<Tag> tags = new ArrayList<>();
 
   /**
@@ -130,12 +135,13 @@ public class PetComposition {
 
   public static final String SERIALIZED_NAME_STATUS = "status";
   @SerializedName(SERIALIZED_NAME_STATUS)
+  @javax.annotation.Nullable
   private StatusEnum status;
 
   public PetComposition() {
   }
 
-  public PetComposition id(Long id) {
+  public PetComposition id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -149,12 +155,12 @@ public class PetComposition {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public PetComposition category(Category category) {
+  public PetComposition category(@javax.annotation.Nullable Category category) {
     this.category = category;
     return this;
   }
@@ -168,12 +174,12 @@ public class PetComposition {
     return category;
   }
 
-  public void setCategory(Category category) {
+  public void setCategory(@javax.annotation.Nullable Category category) {
     this.category = category;
   }
 
 
-  public PetComposition name(String name) {
+  public PetComposition name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -187,12 +193,12 @@ public class PetComposition {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public PetComposition photoUrls(List<String> photoUrls) {
+  public PetComposition photoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
     return this;
   }
@@ -214,12 +220,12 @@ public class PetComposition {
     return photoUrls;
   }
 
-  public void setPhotoUrls(List<String> photoUrls) {
+  public void setPhotoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
   }
 
 
-  public PetComposition tags(List<Tag> tags) {
+  public PetComposition tags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
     return this;
   }
@@ -241,12 +247,12 @@ public class PetComposition {
     return tags;
   }
 
-  public void setTags(List<Tag> tags) {
+  public void setTags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
   }
 
 
-  public PetComposition status(StatusEnum status) {
+  public PetComposition status(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
     return this;
   }
@@ -260,7 +266,7 @@ public class PetComposition {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetRef.java

@@ -56,22 +56,27 @@ import org.openapitools.client.JSON;
 public class PetRef {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_CATEGORY = "category";
   @SerializedName(SERIALIZED_NAME_CATEGORY)
+  @javax.annotation.Nullable
   private Category category;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name;
 
   public static final String SERIALIZED_NAME_PHOTO_URLS = "photoUrls";
   @SerializedName(SERIALIZED_NAME_PHOTO_URLS)
+  @javax.annotation.Nonnull
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
+  @javax.annotation.Nullable
   private List<Tag> tags = new ArrayList<>();
 
   /**
@@ -130,12 +135,13 @@ public class PetRef {
 
   public static final String SERIALIZED_NAME_STATUS = "status";
   @SerializedName(SERIALIZED_NAME_STATUS)
+  @javax.annotation.Nullable
   private StatusEnum status;
 
   public PetRef() {
   }
 
-  public PetRef id(Long id) {
+  public PetRef id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -149,12 +155,12 @@ public class PetRef {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public PetRef category(Category category) {
+  public PetRef category(@javax.annotation.Nullable Category category) {
     this.category = category;
     return this;
   }
@@ -168,12 +174,12 @@ public class PetRef {
     return category;
   }
 
-  public void setCategory(Category category) {
+  public void setCategory(@javax.annotation.Nullable Category category) {
     this.category = category;
   }
 
 
-  public PetRef name(String name) {
+  public PetRef name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -187,12 +193,12 @@ public class PetRef {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public PetRef photoUrls(List<String> photoUrls) {
+  public PetRef photoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
     return this;
   }
@@ -214,12 +220,12 @@ public class PetRef {
     return photoUrls;
   }
 
-  public void setPhotoUrls(List<String> photoUrls) {
+  public void setPhotoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
   }
 
 
-  public PetRef tags(List<Tag> tags) {
+  public PetRef tags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
     return this;
   }
@@ -241,12 +247,12 @@ public class PetRef {
     return tags;
   }
 
-  public void setTags(List<Tag> tags) {
+  public void setTags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
   }
 
 
-  public PetRef status(StatusEnum status) {
+  public PetRef status(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
     return this;
   }
@@ -260,7 +266,7 @@ public class PetRef {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetUsingAllOf.java

@@ -56,22 +56,27 @@ import org.openapitools.client.JSON;
 public class PetUsingAllOf {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_CATEGORY = "category";
   @SerializedName(SERIALIZED_NAME_CATEGORY)
+  @javax.annotation.Nullable
   private Category category;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name;
 
   public static final String SERIALIZED_NAME_PHOTO_URLS = "photoUrls";
   @SerializedName(SERIALIZED_NAME_PHOTO_URLS)
+  @javax.annotation.Nonnull
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
+  @javax.annotation.Nullable
   private List<Tag> tags = new ArrayList<>();
 
   /**
@@ -130,12 +135,13 @@ public class PetUsingAllOf {
 
   public static final String SERIALIZED_NAME_STATUS = "status";
   @SerializedName(SERIALIZED_NAME_STATUS)
+  @javax.annotation.Nullable
   private StatusEnum status;
 
   public PetUsingAllOf() {
   }
 
-  public PetUsingAllOf id(Long id) {
+  public PetUsingAllOf id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -149,12 +155,12 @@ public class PetUsingAllOf {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public PetUsingAllOf category(Category category) {
+  public PetUsingAllOf category(@javax.annotation.Nullable Category category) {
     this.category = category;
     return this;
   }
@@ -168,12 +174,12 @@ public class PetUsingAllOf {
     return category;
   }
 
-  public void setCategory(Category category) {
+  public void setCategory(@javax.annotation.Nullable Category category) {
     this.category = category;
   }
 
 
-  public PetUsingAllOf name(String name) {
+  public PetUsingAllOf name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -187,12 +193,12 @@ public class PetUsingAllOf {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public PetUsingAllOf photoUrls(List<String> photoUrls) {
+  public PetUsingAllOf photoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
     return this;
   }
@@ -214,12 +220,12 @@ public class PetUsingAllOf {
     return photoUrls;
   }
 
-  public void setPhotoUrls(List<String> photoUrls) {
+  public void setPhotoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
   }
 
 
-  public PetUsingAllOf tags(List<Tag> tags) {
+  public PetUsingAllOf tags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
     return this;
   }
@@ -241,12 +247,12 @@ public class PetUsingAllOf {
     return tags;
   }
 
-  public void setTags(List<Tag> tags) {
+  public void setTags(@javax.annotation.Nullable List<Tag> tags) {
     this.tags = tags;
   }
 
 
-  public PetUsingAllOf status(StatusEnum status) {
+  public PetUsingAllOf status(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
     return this;
   }
@@ -260,7 +266,7 @@ public class PetUsingAllOf {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PetWithRequiredTags.java

@@ -56,22 +56,27 @@ import org.openapitools.client.JSON;
 public class PetWithRequiredTags {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_CATEGORY = "category";
   @SerializedName(SERIALIZED_NAME_CATEGORY)
+  @javax.annotation.Nullable
   private Category category;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name;
 
   public static final String SERIALIZED_NAME_PHOTO_URLS = "photoUrls";
   @SerializedName(SERIALIZED_NAME_PHOTO_URLS)
+  @javax.annotation.Nonnull
   private List<String> photoUrls = new ArrayList<>();
 
   public static final String SERIALIZED_NAME_TAGS = "tags";
   @SerializedName(SERIALIZED_NAME_TAGS)
+  @javax.annotation.Nonnull
   private List<Tag> tags = new ArrayList<>();
 
   /**
@@ -130,12 +135,13 @@ public class PetWithRequiredTags {
 
   public static final String SERIALIZED_NAME_STATUS = "status";
   @SerializedName(SERIALIZED_NAME_STATUS)
+  @javax.annotation.Nullable
   private StatusEnum status;
 
   public PetWithRequiredTags() {
   }
 
-  public PetWithRequiredTags id(Long id) {
+  public PetWithRequiredTags id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -149,12 +155,12 @@ public class PetWithRequiredTags {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public PetWithRequiredTags category(Category category) {
+  public PetWithRequiredTags category(@javax.annotation.Nullable Category category) {
     this.category = category;
     return this;
   }
@@ -168,12 +174,12 @@ public class PetWithRequiredTags {
     return category;
   }
 
-  public void setCategory(Category category) {
+  public void setCategory(@javax.annotation.Nullable Category category) {
     this.category = category;
   }
 
 
-  public PetWithRequiredTags name(String name) {
+  public PetWithRequiredTags name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -187,12 +193,12 @@ public class PetWithRequiredTags {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public PetWithRequiredTags photoUrls(List<String> photoUrls) {
+  public PetWithRequiredTags photoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
     return this;
   }
@@ -214,12 +220,12 @@ public class PetWithRequiredTags {
     return photoUrls;
   }
 
-  public void setPhotoUrls(List<String> photoUrls) {
+  public void setPhotoUrls(@javax.annotation.Nonnull List<String> photoUrls) {
     this.photoUrls = photoUrls;
   }
 
 
-  public PetWithRequiredTags tags(List<Tag> tags) {
+  public PetWithRequiredTags tags(@javax.annotation.Nonnull List<Tag> tags) {
     this.tags = tags;
     return this;
   }
@@ -241,12 +247,12 @@ public class PetWithRequiredTags {
     return tags;
   }
 
-  public void setTags(List<Tag> tags) {
+  public void setTags(@javax.annotation.Nonnull List<Tag> tags) {
     this.tags = tags;
   }
 
 
-  public PetWithRequiredTags status(StatusEnum status) {
+  public PetWithRequiredTags status(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
     return this;
   }
@@ -260,7 +266,7 @@ public class PetWithRequiredTags {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(@javax.annotation.Nullable StatusEnum status) {
     this.status = status;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/PropertyNameCollision.java

@@ -52,20 +52,23 @@ import org.openapitools.client.JSON;
 public class PropertyNameCollision {
   public static final String SERIALIZED_NAME_UNDERSCORE_TYPE = "_type";
   @SerializedName(SERIALIZED_NAME_UNDERSCORE_TYPE)
+  @javax.annotation.Nullable
   private String underscoreType;
 
   public static final String SERIALIZED_NAME_TYPE = "type";
   @SerializedName(SERIALIZED_NAME_TYPE)
+  @javax.annotation.Nullable
   private String type;
 
   public static final String SERIALIZED_NAME_TYPE_WITH_UNDERSCORE = "type_";
   @SerializedName(SERIALIZED_NAME_TYPE_WITH_UNDERSCORE)
+  @javax.annotation.Nullable
   private String typeWithUnderscore;
 
   public PropertyNameCollision() {
   }
 
-  public PropertyNameCollision underscoreType(String underscoreType) {
+  public PropertyNameCollision underscoreType(@javax.annotation.Nullable String underscoreType) {
     this.underscoreType = underscoreType;
     return this;
   }
@@ -79,12 +82,12 @@ public class PropertyNameCollision {
     return underscoreType;
   }
 
-  public void setUnderscoreType(String underscoreType) {
+  public void setUnderscoreType(@javax.annotation.Nullable String underscoreType) {
     this.underscoreType = underscoreType;
   }
 
 
-  public PropertyNameCollision type(String type) {
+  public PropertyNameCollision type(@javax.annotation.Nullable String type) {
     this.type = type;
     return this;
   }
@@ -98,12 +101,12 @@ public class PropertyNameCollision {
     return type;
   }
 
-  public void setType(String type) {
+  public void setType(@javax.annotation.Nullable String type) {
     this.type = type;
   }
 
 
-  public PropertyNameCollision typeWithUnderscore(String typeWithUnderscore) {
+  public PropertyNameCollision typeWithUnderscore(@javax.annotation.Nullable String typeWithUnderscore) {
     this.typeWithUnderscore = typeWithUnderscore;
     return this;
   }
@@ -117,7 +120,7 @@ public class PropertyNameCollision {
     return typeWithUnderscore;
   }
 
-  public void setTypeWithUnderscore(String typeWithUnderscore) {
+  public void setTypeWithUnderscore(@javax.annotation.Nullable String typeWithUnderscore) {
     this.typeWithUnderscore = typeWithUnderscore;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/QuadrilateralInterface.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class QuadrilateralInterface {
   public static final String SERIALIZED_NAME_QUADRILATERAL_TYPE = "quadrilateralType";
   @SerializedName(SERIALIZED_NAME_QUADRILATERAL_TYPE)
+  @javax.annotation.Nonnull
   private String quadrilateralType;
 
   public QuadrilateralInterface() {
   }
 
-  public QuadrilateralInterface quadrilateralType(String quadrilateralType) {
+  public QuadrilateralInterface quadrilateralType(@javax.annotation.Nonnull String quadrilateralType) {
     this.quadrilateralType = quadrilateralType;
     return this;
   }
@@ -71,7 +72,7 @@ public class QuadrilateralInterface {
     return quadrilateralType;
   }
 
-  public void setQuadrilateralType(String quadrilateralType) {
+  public void setQuadrilateralType(@javax.annotation.Nonnull String quadrilateralType) {
     this.quadrilateralType = quadrilateralType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java

@@ -52,10 +52,12 @@ import org.openapitools.client.JSON;
 public class ReadOnlyFirst {
   public static final String SERIALIZED_NAME_BAR = "bar";
   @SerializedName(SERIALIZED_NAME_BAR)
+  @javax.annotation.Nullable
   private String bar;
 
   public static final String SERIALIZED_NAME_BAZ = "baz";
   @SerializedName(SERIALIZED_NAME_BAZ)
+  @javax.annotation.Nullable
   private String baz;
 
   public ReadOnlyFirst() {
@@ -79,7 +81,7 @@ public class ReadOnlyFirst {
 
 
 
-  public ReadOnlyFirst baz(String baz) {
+  public ReadOnlyFirst baz(@javax.annotation.Nullable String baz) {
     this.baz = baz;
     return this;
   }
@@ -93,7 +95,7 @@ public class ReadOnlyFirst {
     return baz;
   }
 
-  public void setBaz(String baz) {
+  public void setBaz(@javax.annotation.Nullable String baz) {
     this.baz = baz;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ScaleneTriangle.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class ScaleneTriangle {
   public static final String SERIALIZED_NAME_SHAPE_TYPE = "shapeType";
   @SerializedName(SERIALIZED_NAME_SHAPE_TYPE)
+  @javax.annotation.Nonnull
   private String shapeType;
 
   public static final String SERIALIZED_NAME_TRIANGLE_TYPE = "triangleType";
   @SerializedName(SERIALIZED_NAME_TRIANGLE_TYPE)
+  @javax.annotation.Nonnull
   private String triangleType;
 
   public ScaleneTriangle() {
   }
 
-  public ScaleneTriangle shapeType(String shapeType) {
+  public ScaleneTriangle shapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
     return this;
   }
@@ -75,12 +77,12 @@ public class ScaleneTriangle {
     return shapeType;
   }
 
-  public void setShapeType(String shapeType) {
+  public void setShapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
   }
 
 
-  public ScaleneTriangle triangleType(String triangleType) {
+  public ScaleneTriangle triangleType(@javax.annotation.Nonnull String triangleType) {
     this.triangleType = triangleType;
     return this;
   }
@@ -94,7 +96,7 @@ public class ScaleneTriangle {
     return triangleType;
   }
 
-  public void setTriangleType(String triangleType) {
+  public void setTriangleType(@javax.annotation.Nonnull String triangleType) {
     this.triangleType = triangleType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/ShapeInterface.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class ShapeInterface {
   public static final String SERIALIZED_NAME_SHAPE_TYPE = "shapeType";
   @SerializedName(SERIALIZED_NAME_SHAPE_TYPE)
+  @javax.annotation.Nonnull
   private String shapeType;
 
   public ShapeInterface() {
   }
 
-  public ShapeInterface shapeType(String shapeType) {
+  public ShapeInterface shapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
     return this;
   }
@@ -71,7 +72,7 @@ public class ShapeInterface {
     return shapeType;
   }
 
-  public void setShapeType(String shapeType) {
+  public void setShapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SimpleQuadrilateral.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class SimpleQuadrilateral {
   public static final String SERIALIZED_NAME_SHAPE_TYPE = "shapeType";
   @SerializedName(SERIALIZED_NAME_SHAPE_TYPE)
+  @javax.annotation.Nonnull
   private String shapeType;
 
   public static final String SERIALIZED_NAME_QUADRILATERAL_TYPE = "quadrilateralType";
   @SerializedName(SERIALIZED_NAME_QUADRILATERAL_TYPE)
+  @javax.annotation.Nonnull
   private String quadrilateralType;
 
   public SimpleQuadrilateral() {
   }
 
-  public SimpleQuadrilateral shapeType(String shapeType) {
+  public SimpleQuadrilateral shapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
     return this;
   }
@@ -75,12 +77,12 @@ public class SimpleQuadrilateral {
     return shapeType;
   }
 
-  public void setShapeType(String shapeType) {
+  public void setShapeType(@javax.annotation.Nonnull String shapeType) {
     this.shapeType = shapeType;
   }
 
 
-  public SimpleQuadrilateral quadrilateralType(String quadrilateralType) {
+  public SimpleQuadrilateral quadrilateralType(@javax.annotation.Nonnull String quadrilateralType) {
     this.quadrilateralType = quadrilateralType;
     return this;
   }
@@ -94,7 +96,7 @@ public class SimpleQuadrilateral {
     return quadrilateralType;
   }
 
-  public void setQuadrilateralType(String quadrilateralType) {
+  public void setQuadrilateralType(@javax.annotation.Nonnull String quadrilateralType) {
     this.quadrilateralType = quadrilateralType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/SpecialModelName.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class SpecialModelName {
   public static final String SERIALIZED_NAME_$_SPECIAL_PROPERTY_NAME = "$special[property.name]";
   @SerializedName(SERIALIZED_NAME_$_SPECIAL_PROPERTY_NAME)
+  @javax.annotation.Nullable
   private Long $specialPropertyName;
 
   public static final String SERIALIZED_NAME_SPECIAL_MODEL_NAME = "_special_model.name_";
   @SerializedName(SERIALIZED_NAME_SPECIAL_MODEL_NAME)
+  @javax.annotation.Nullable
   private String specialModelName;
 
   public SpecialModelName() {
   }
 
-  public SpecialModelName $specialPropertyName(Long $specialPropertyName) {
+  public SpecialModelName $specialPropertyName(@javax.annotation.Nullable Long $specialPropertyName) {
     this.$specialPropertyName = $specialPropertyName;
     return this;
   }
@@ -75,12 +77,12 @@ public class SpecialModelName {
     return $specialPropertyName;
   }
 
-  public void set$SpecialPropertyName(Long $specialPropertyName) {
+  public void set$SpecialPropertyName(@javax.annotation.Nullable Long $specialPropertyName) {
     this.$specialPropertyName = $specialPropertyName;
   }
 
 
-  public SpecialModelName specialModelName(String specialModelName) {
+  public SpecialModelName specialModelName(@javax.annotation.Nullable String specialModelName) {
     this.specialModelName = specialModelName;
     return this;
   }
@@ -94,7 +96,7 @@ public class SpecialModelName {
     return specialModelName;
   }
 
-  public void setSpecialModelName(String specialModelName) {
+  public void setSpecialModelName(@javax.annotation.Nullable String specialModelName) {
     this.specialModelName = specialModelName;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Tag.java

@@ -52,16 +52,18 @@ import org.openapitools.client.JSON;
 public class Tag {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nullable
   private String name;
 
   public Tag() {
   }
 
-  public Tag id(Long id) {
+  public Tag id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -75,12 +77,12 @@ public class Tag {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public Tag name(String name) {
+  public Tag name(@javax.annotation.Nullable String name) {
     this.name = name;
     return this;
   }
@@ -94,7 +96,7 @@ public class Tag {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nullable String name) {
     this.name = name;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TestInlineFreeformAdditionalPropertiesRequest.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class TestInlineFreeformAdditionalPropertiesRequest {
   public static final String SERIALIZED_NAME_SOME_PROPERTY = "someProperty";
   @SerializedName(SERIALIZED_NAME_SOME_PROPERTY)
+  @javax.annotation.Nullable
   private String someProperty;
 
   public TestInlineFreeformAdditionalPropertiesRequest() {
   }
 
-  public TestInlineFreeformAdditionalPropertiesRequest someProperty(String someProperty) {
+  public TestInlineFreeformAdditionalPropertiesRequest someProperty(@javax.annotation.Nullable String someProperty) {
     this.someProperty = someProperty;
     return this;
   }
@@ -71,7 +72,7 @@ public class TestInlineFreeformAdditionalPropertiesRequest {
     return someProperty;
   }
 
-  public void setSomeProperty(String someProperty) {
+  public void setSomeProperty(@javax.annotation.Nullable String someProperty) {
     this.someProperty = someProperty;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/TriangleInterface.java

@@ -52,12 +52,13 @@ import org.openapitools.client.JSON;
 public class TriangleInterface {
   public static final String SERIALIZED_NAME_TRIANGLE_TYPE = "triangleType";
   @SerializedName(SERIALIZED_NAME_TRIANGLE_TYPE)
+  @javax.annotation.Nonnull
   private String triangleType;
 
   public TriangleInterface() {
   }
 
-  public TriangleInterface triangleType(String triangleType) {
+  public TriangleInterface triangleType(@javax.annotation.Nonnull String triangleType) {
     this.triangleType = triangleType;
     return this;
   }
@@ -71,7 +72,7 @@ public class TriangleInterface {
     return triangleType;
   }
 
-  public void setTriangleType(String triangleType) {
+  public void setTriangleType(@javax.annotation.Nonnull String triangleType) {
     this.triangleType = triangleType;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/User.java

@@ -53,56 +53,68 @@ import org.openapitools.client.JSON;
 public class User {
   public static final String SERIALIZED_NAME_ID = "id";
   @SerializedName(SERIALIZED_NAME_ID)
+  @javax.annotation.Nullable
   private Long id;
 
   public static final String SERIALIZED_NAME_USERNAME = "username";
   @SerializedName(SERIALIZED_NAME_USERNAME)
+  @javax.annotation.Nullable
   private String username;
 
   public static final String SERIALIZED_NAME_FIRST_NAME = "firstName";
   @SerializedName(SERIALIZED_NAME_FIRST_NAME)
+  @javax.annotation.Nullable
   private String firstName;
 
   public static final String SERIALIZED_NAME_LAST_NAME = "lastName";
   @SerializedName(SERIALIZED_NAME_LAST_NAME)
+  @javax.annotation.Nullable
   private String lastName;
 
   public static final String SERIALIZED_NAME_EMAIL = "email";
   @SerializedName(SERIALIZED_NAME_EMAIL)
+  @javax.annotation.Nullable
   private String email;
 
   public static final String SERIALIZED_NAME_PASSWORD = "password";
   @SerializedName(SERIALIZED_NAME_PASSWORD)
+  @javax.annotation.Nullable
   private String password;
 
   public static final String SERIALIZED_NAME_PHONE = "phone";
   @SerializedName(SERIALIZED_NAME_PHONE)
+  @javax.annotation.Nullable
   private String phone;
 
   public static final String SERIALIZED_NAME_USER_STATUS = "userStatus";
   @SerializedName(SERIALIZED_NAME_USER_STATUS)
+  @javax.annotation.Nullable
   private Integer userStatus;
 
   public static final String SERIALIZED_NAME_OBJECT_WITH_NO_DECLARED_PROPS = "objectWithNoDeclaredProps";
   @SerializedName(SERIALIZED_NAME_OBJECT_WITH_NO_DECLARED_PROPS)
+  @javax.annotation.Nullable
   private Object objectWithNoDeclaredProps;
 
   public static final String SERIALIZED_NAME_OBJECT_WITH_NO_DECLARED_PROPS_NULLABLE = "objectWithNoDeclaredPropsNullable";
   @SerializedName(SERIALIZED_NAME_OBJECT_WITH_NO_DECLARED_PROPS_NULLABLE)
+  @javax.annotation.Nullable
   private Object objectWithNoDeclaredPropsNullable;
 
   public static final String SERIALIZED_NAME_ANY_TYPE_PROP = "anyTypeProp";
   @SerializedName(SERIALIZED_NAME_ANY_TYPE_PROP)
+  @javax.annotation.Nullable
   private Object anyTypeProp = null;
 
   public static final String SERIALIZED_NAME_ANY_TYPE_PROP_NULLABLE = "anyTypePropNullable";
   @SerializedName(SERIALIZED_NAME_ANY_TYPE_PROP_NULLABLE)
+  @javax.annotation.Nullable
   private Object anyTypePropNullable = null;
 
   public User() {
   }
 
-  public User id(Long id) {
+  public User id(@javax.annotation.Nullable Long id) {
     this.id = id;
     return this;
   }
@@ -116,12 +128,12 @@ public class User {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(@javax.annotation.Nullable Long id) {
     this.id = id;
   }
 
 
-  public User username(String username) {
+  public User username(@javax.annotation.Nullable String username) {
     this.username = username;
     return this;
   }
@@ -135,12 +147,12 @@ public class User {
     return username;
   }
 
-  public void setUsername(String username) {
+  public void setUsername(@javax.annotation.Nullable String username) {
     this.username = username;
   }
 
 
-  public User firstName(String firstName) {
+  public User firstName(@javax.annotation.Nullable String firstName) {
     this.firstName = firstName;
     return this;
   }
@@ -154,12 +166,12 @@ public class User {
     return firstName;
   }
 
-  public void setFirstName(String firstName) {
+  public void setFirstName(@javax.annotation.Nullable String firstName) {
     this.firstName = firstName;
   }
 
 
-  public User lastName(String lastName) {
+  public User lastName(@javax.annotation.Nullable String lastName) {
     this.lastName = lastName;
     return this;
   }
@@ -173,12 +185,12 @@ public class User {
     return lastName;
   }
 
-  public void setLastName(String lastName) {
+  public void setLastName(@javax.annotation.Nullable String lastName) {
     this.lastName = lastName;
   }
 
 
-  public User email(String email) {
+  public User email(@javax.annotation.Nullable String email) {
     this.email = email;
     return this;
   }
@@ -192,12 +204,12 @@ public class User {
     return email;
   }
 
-  public void setEmail(String email) {
+  public void setEmail(@javax.annotation.Nullable String email) {
     this.email = email;
   }
 
 
-  public User password(String password) {
+  public User password(@javax.annotation.Nullable String password) {
     this.password = password;
     return this;
   }
@@ -211,12 +223,12 @@ public class User {
     return password;
   }
 
-  public void setPassword(String password) {
+  public void setPassword(@javax.annotation.Nullable String password) {
     this.password = password;
   }
 
 
-  public User phone(String phone) {
+  public User phone(@javax.annotation.Nullable String phone) {
     this.phone = phone;
     return this;
   }
@@ -230,12 +242,12 @@ public class User {
     return phone;
   }
 
-  public void setPhone(String phone) {
+  public void setPhone(@javax.annotation.Nullable String phone) {
     this.phone = phone;
   }
 
 
-  public User userStatus(Integer userStatus) {
+  public User userStatus(@javax.annotation.Nullable Integer userStatus) {
     this.userStatus = userStatus;
     return this;
   }
@@ -249,12 +261,12 @@ public class User {
     return userStatus;
   }
 
-  public void setUserStatus(Integer userStatus) {
+  public void setUserStatus(@javax.annotation.Nullable Integer userStatus) {
     this.userStatus = userStatus;
   }
 
 
-  public User objectWithNoDeclaredProps(Object objectWithNoDeclaredProps) {
+  public User objectWithNoDeclaredProps(@javax.annotation.Nullable Object objectWithNoDeclaredProps) {
     this.objectWithNoDeclaredProps = objectWithNoDeclaredProps;
     return this;
   }
@@ -268,12 +280,12 @@ public class User {
     return objectWithNoDeclaredProps;
   }
 
-  public void setObjectWithNoDeclaredProps(Object objectWithNoDeclaredProps) {
+  public void setObjectWithNoDeclaredProps(@javax.annotation.Nullable Object objectWithNoDeclaredProps) {
     this.objectWithNoDeclaredProps = objectWithNoDeclaredProps;
   }
 
 
-  public User objectWithNoDeclaredPropsNullable(Object objectWithNoDeclaredPropsNullable) {
+  public User objectWithNoDeclaredPropsNullable(@javax.annotation.Nullable Object objectWithNoDeclaredPropsNullable) {
     this.objectWithNoDeclaredPropsNullable = objectWithNoDeclaredPropsNullable;
     return this;
   }
@@ -287,12 +299,12 @@ public class User {
     return objectWithNoDeclaredPropsNullable;
   }
 
-  public void setObjectWithNoDeclaredPropsNullable(Object objectWithNoDeclaredPropsNullable) {
+  public void setObjectWithNoDeclaredPropsNullable(@javax.annotation.Nullable Object objectWithNoDeclaredPropsNullable) {
     this.objectWithNoDeclaredPropsNullable = objectWithNoDeclaredPropsNullable;
   }
 
 
-  public User anyTypeProp(Object anyTypeProp) {
+  public User anyTypeProp(@javax.annotation.Nullable Object anyTypeProp) {
     this.anyTypeProp = anyTypeProp;
     return this;
   }
@@ -306,12 +318,12 @@ public class User {
     return anyTypeProp;
   }
 
-  public void setAnyTypeProp(Object anyTypeProp) {
+  public void setAnyTypeProp(@javax.annotation.Nullable Object anyTypeProp) {
     this.anyTypeProp = anyTypeProp;
   }
 
 
-  public User anyTypePropNullable(Object anyTypePropNullable) {
+  public User anyTypePropNullable(@javax.annotation.Nullable Object anyTypePropNullable) {
     this.anyTypePropNullable = anyTypePropNullable;
     return this;
   }
@@ -325,7 +337,7 @@ public class User {
     return anyTypePropNullable;
   }
 
-  public void setAnyTypePropNullable(Object anyTypePropNullable) {
+  public void setAnyTypePropNullable(@javax.annotation.Nullable Object anyTypePropNullable) {
     this.anyTypePropNullable = anyTypePropNullable;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Variable.java

@@ -53,16 +53,18 @@ import org.openapitools.client.JSON;
 public class Variable {
   public static final String SERIALIZED_NAME_NAME = "name";
   @SerializedName(SERIALIZED_NAME_NAME)
+  @javax.annotation.Nonnull
   private String name;
 
   public static final String SERIALIZED_NAME_VALUE = "value";
   @SerializedName(SERIALIZED_NAME_VALUE)
+  @javax.annotation.Nonnull
   private Value value;
 
   public Variable() {
   }
 
-  public Variable name(String name) {
+  public Variable name(@javax.annotation.Nonnull String name) {
     this.name = name;
     return this;
   }
@@ -76,12 +78,12 @@ public class Variable {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(@javax.annotation.Nonnull String name) {
     this.name = name;
   }
 
 
-  public Variable value(Value value) {
+  public Variable value(@javax.annotation.Nonnull Value value) {
     this.value = value;
     return this;
   }
@@ -95,7 +97,7 @@ public class Variable {
     return value;
   }
 
-  public void setValue(Value value) {
+  public void setValue(@javax.annotation.Nonnull Value value) {
     this.value = value;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Whale.java

@@ -52,20 +52,23 @@ import org.openapitools.client.JSON;
 public class Whale {
   public static final String SERIALIZED_NAME_HAS_BALEEN = "hasBaleen";
   @SerializedName(SERIALIZED_NAME_HAS_BALEEN)
+  @javax.annotation.Nullable
   private Boolean hasBaleen;
 
   public static final String SERIALIZED_NAME_HAS_TEETH = "hasTeeth";
   @SerializedName(SERIALIZED_NAME_HAS_TEETH)
+  @javax.annotation.Nullable
   private Boolean hasTeeth;
 
   public static final String SERIALIZED_NAME_CLASS_NAME = "className";
   @SerializedName(SERIALIZED_NAME_CLASS_NAME)
+  @javax.annotation.Nonnull
   private String className;
 
   public Whale() {
   }
 
-  public Whale hasBaleen(Boolean hasBaleen) {
+  public Whale hasBaleen(@javax.annotation.Nullable Boolean hasBaleen) {
     this.hasBaleen = hasBaleen;
     return this;
   }
@@ -79,12 +82,12 @@ public class Whale {
     return hasBaleen;
   }
 
-  public void setHasBaleen(Boolean hasBaleen) {
+  public void setHasBaleen(@javax.annotation.Nullable Boolean hasBaleen) {
     this.hasBaleen = hasBaleen;
   }
 
 
-  public Whale hasTeeth(Boolean hasTeeth) {
+  public Whale hasTeeth(@javax.annotation.Nullable Boolean hasTeeth) {
     this.hasTeeth = hasTeeth;
     return this;
   }
@@ -98,12 +101,12 @@ public class Whale {
     return hasTeeth;
   }
 
-  public void setHasTeeth(Boolean hasTeeth) {
+  public void setHasTeeth(@javax.annotation.Nullable Boolean hasTeeth) {
     this.hasTeeth = hasTeeth;
   }
 
 
-  public Whale className(String className) {
+  public Whale className(@javax.annotation.Nonnull String className) {
     this.className = className;
     return this;
   }
@@ -117,7 +120,7 @@ public class Whale {
     return className;
   }
 
-  public void setClassName(String className) {
+  public void setClassName(@javax.annotation.Nonnull String className) {
     this.className = className;
   }
 

samples/client/petstore/java/okhttp-gson/src/main/java/org/openapitools/client/model/Zebra.java

@@ -106,16 +106,18 @@ public class Zebra {
 
   public static final String SERIALIZED_NAME_TYPE = "type";
   @SerializedName(SERIALIZED_NAME_TYPE)
+  @javax.annotation.Nullable
   private TypeEnum type;
 
   public static final String SERIALIZED_NAME_CLASS_NAME = "className";
   @SerializedName(SERIALIZED_NAME_CLASS_NAME)
+  @javax.annotation.Nonnull
   private String className;
 
   public Zebra() {
   }
 
-  public Zebra type(TypeEnum type) {
+  public Zebra type(@javax.annotation.Nullable TypeEnum type) {
     this.type = type;
     return this;
   }
@@ -129,12 +131,12 @@ public class Zebra {
     return type;
   }
 
-  public void setType(TypeEnum type) {
+  public void setType(@javax.annotation.Nullable TypeEnum type) {
     this.type = type;
   }
 
 
-  public Zebra className(String className) {
+  public Zebra className(@javax.annotation.Nonnull String className) {
     this.className = className;
     return this;
   }
@@ -148,7 +150,7 @@ public class Zebra {
     return className;
   }
 
-  public void setClassName(String className) {
+  public void setClassName(@javax.annotation.Nonnull String className) {
     this.className = className;
   }