Add Java Optional for POJOs in JavaSpring templates (#17202)

* Add optional parameter for request body

* Adapt Test

* Add test

* Format code

* Remove extra method

* Add optional for pojos

* Add optional for pojos

* Add bean validation for Optional

* Add default values + test

* Rename test

modules/openapi-generator/src/main/resources/JavaSpring/beanValidation.mustache

@@ -1 +1 @@
-{{#required}}{{^isReadOnly}}@NotNull {{/isReadOnly}}{{/required}}{{#isContainer}}{{^isPrimitiveType}}{{^isEnum}}@Valid {{/isEnum}}{{/isPrimitiveType}}{{/isContainer}}{{^isContainer}}{{^isPrimitiveType}}@Valid {{/isPrimitiveType}}{{/isContainer}}{{>beanValidationCore}}
+{{#required}}{{^isReadOnly}}@NotNull {{/isReadOnly}}{{/required}}{{#isContainer}}{{^isPrimitiveType}}{{^isEnum}}@Valid {{/isEnum}}{{/isPrimitiveType}}{{/isContainer}}{{^isContainer}}{{^isPrimitiveType}}@Valid {{/isPrimitiveType}}{{/isContainer}}{{^openApiNullable}}{{>beanValidationCore}}{{/openApiNullable}}{{#openApiNullable}}{{^useOptional}}{{>beanValidationCore}}{{/useOptional}}{{/openApiNullable}}{{#useOptional}}{{#openApiNullable}}{{#isContainer}}{{^required}}{{>beanValidationCore}}{{/required}}{{/isContainer}}{{/openApiNullable}}{{#openApiNullable}}{{#required}}{{>beanValidationCore}}{{/required}}{{/openApiNullable}}{{/useOptional}}

modules/openapi-generator/src/main/resources/JavaSpring/beanValidationCore.mustache

@@ -12,9 +12,9 @@ minLength not set, maxLength set
 @Size: minItems not set && maxItems set
 }}{{^minItems}}{{#maxItems}}@Size(max = {{.}}) {{/maxItems}}{{/minItems}}{{!
 @Email: useBeanValidation
-}}{{#isEmail}}{{#useBeanValidation}}@{{javaxPackage}}.validation.constraints.Email{{/useBeanValidation}}{{!
+}}{{#isEmail}}{{#useBeanValidation}}@{{javaxPackage}}.validation.constraints.Email {{/useBeanValidation}}{{!
 @Email: performBeanValidation exclusive
-}}{{^useBeanValidation}}{{#performBeanValidation}}@org.hibernate.validator.constraints.Email{{/performBeanValidation}}{{/useBeanValidation}}{{/isEmail}}{{!
+}}{{^useBeanValidation}}{{#performBeanValidation}}@org.hibernate.validator.constraints.Email {{/performBeanValidation}}{{/useBeanValidation}}{{/isEmail}}{{!
 check for integer or long / all others=decimal type with @Decimal*
 isInteger set
 }}{{#isInteger}}{{#minimum}}@Min({{.}}) {{/minimum}}{{#maximum}}@Max({{.}}) {{/maximum}}{{/isInteger}}{{!

modules/openapi-generator/src/main/resources/JavaSpring/nullableDataType.mustache

@@ -1 +1 @@
-{{#openApiNullable}}{{#isNullable}}JsonNullable<{{{datatypeWithEnum}}}>{{/isNullable}}{{^isNullable}}{{{datatypeWithEnum}}}{{/isNullable}}{{/openApiNullable}}{{^openApiNullable}}{{{datatypeWithEnum}}}{{/openApiNullable}}
+{{#openApiNullable}}{{#isNullable}}JsonNullable<{{/isNullable}}{{#useOptional}}{{^required}}{{^isNullable}}{{^isContainer}}Optional<{{/isContainer}}{{/isNullable}}{{/required}}{{/useOptional}}{{/openApiNullable}}{{{datatypeWithEnum}}}{{#openApiNullable}}{{#isNullable}}>{{/isNullable}}{{#useOptional}}{{^required}}{{^isNullable}}{{^isContainer}}>{{/isContainer}}{{/isNullable}}{{/required}}{{/useOptional}}{{/openApiNullable}}

modules/openapi-generator/src/main/resources/JavaSpring/nullableDataTypeBeanValidation.mustache

@@ -0,0 +1 @@
+{{#openApiNullable}}{{#isNullable}}{{^isContainer}}JsonNullable<{{#useBeanValidation}}{{>beanValidationCore}}{{/useBeanValidation}}{{/isContainer}}{{#isContainer}}JsonNullable<{{/isContainer}}{{/isNullable}}{{#useOptional}}{{^required}}{{^isNullable}}{{^isContainer}}Optional<{{#useBeanValidation}}{{>beanValidationCore}}{{/useBeanValidation}}{{/isContainer}}{{/isNullable}}{{/required}}{{/useOptional}}{{/openApiNullable}}{{{datatypeWithEnum}}}{{#openApiNullable}}{{#isNullable}}>{{/isNullable}}{{#useOptional}}{{^required}}{{^isNullable}}{{^isContainer}}>{{/isContainer}}{{/isNullable}}{{/required}}{{/useOptional}}{{/openApiNullable}}

modules/openapi-generator/src/main/resources/JavaSpring/pojo.mustache

@@ -65,7 +65,7 @@ public class {{classname}}{{#parent}} extends {{{parent}}}{{/parent}}{{^parent}}
   {{#isContainer}}
   {{#useBeanValidation}}@Valid{{/useBeanValidation}}
   {{#openApiNullable}}
-  private {{>nullableDataType}} {{name}}{{#isNullable}} = JsonNullable.<{{{datatypeWithEnum}}}>undefined(){{/isNullable}}{{^isNullable}}{{#defaultValue}} = {{{.}}}{{/defaultValue}}{{/isNullable}};
+  private {{#isNullable}}{{>nullableDataTypeBeanValidation}} {{name}} = JsonNullable.<{{{datatypeWithEnum}}}>undefined();{{/isNullable}}{{^required}}{{^isNullable}}{{>nullableDataTypeBeanValidation}} {{name}}{{#defaultValue}} = {{{.}}}{{/defaultValue}};{{/isNullable}}{{/required}}{{#required}}{{^isNullable}}{{>nullableDataTypeBeanValidation}} {{name}}{{#defaultValue}} = {{{.}}}{{/defaultValue}};{{/isNullable}}{{/required}}
   {{/openApiNullable}}
   {{^openApiNullable}}
   private {{>nullableDataType}} {{name}}{{#defaultValue}} = {{{.}}}{{/defaultValue}};
@@ -79,7 +79,7 @@ public class {{classname}}{{#parent}} extends {{{parent}}}{{/parent}}{{^parent}}
   @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
   {{/isDateTime}}
   {{#openApiNullable}}
-  private {{>nullableDataType}} {{name}}{{#isNullable}} = JsonNullable.<{{{datatypeWithEnum}}}>undefined(){{/isNullable}}{{^isNullable}}{{#defaultValue}} = {{{.}}}{{/defaultValue}}{{/isNullable}};
+  private {{#isNullable}}{{>nullableDataTypeBeanValidation}} {{name}} = JsonNullable.<{{{datatypeWithEnum}}}>undefined();{{/isNullable}}{{^required}}{{^isNullable}}{{>nullableDataTypeBeanValidation}} {{name}}{{#useOptional}} = Optional.{{^defaultValue}}empty(){{/defaultValue}}{{#defaultValue}}of({{{.}}}){{/defaultValue}};{{/useOptional}}{{^useOptional}}{{#defaultValue}} = {{{.}}}{{/defaultValue}};{{/useOptional}}{{/isNullable}}{{/required}}{{^isNullable}}{{#required}}{{>nullableDataTypeBeanValidation}} {{name}}{{#defaultValue}} = {{{.}}}{{/defaultValue}};{{/required}}{{/isNullable}}
   {{/openApiNullable}}
   {{^openApiNullable}}
   private {{>nullableDataType}} {{name}}{{#isNullable}} = null{{/isNullable}}{{^isNullable}}{{#defaultValue}} = {{{.}}}{{/defaultValue}}{{/isNullable}};
@@ -103,7 +103,7 @@ public class {{classname}}{{#parent}} extends {{{parent}}}{{/parent}}{{^parent}}
     {{#vars}}
     {{#required}}
     {{#openApiNullable}}
-    this.{{name}} = {{#isNullable}}JsonNullable.of({{name}}){{/isNullable}}{{^isNullable}}{{name}}{{/isNullable}};
+    this.{{name}} = {{#isNullable}}JsonNullable.of({{/isNullable}}{{#useOptional}}{{^required}}{{^isNullable}}{{^isContainer}}Optional.ofNullable({{/isContainer}}{{/isNullable}}{{/required}}{{/useOptional}}{{name}}{{#isNullable}}){{/isNullable}}{{#useOptional}}{{^required}}{{^isNullable}}{{^isContainer}}){{/isContainer}}{{/isNullable}}{{/required}}{{/useOptional}};
     {{/openApiNullable}}
     {{^openApiNullable}}
     this.{{name}} = {{name}};
@@ -118,7 +118,7 @@ public class {{classname}}{{#parent}} extends {{{parent}}}{{/parent}}{{^parent}}
   {{! begin feature: fluent setter methods }}
   public {{classname}} {{name}}({{{datatypeWithEnum}}} {{name}}) {
     {{#openApiNullable}}
-    this.{{name}} = {{#isNullable}}JsonNullable.of({{name}}){{/isNullable}}{{^isNullable}}{{name}}{{/isNullable}};
+    this.{{name}} = {{#isNullable}}JsonNullable.of({{/isNullable}}{{#useOptional}}{{^required}}{{^isNullable}}{{^isContainer}}Optional.of({{/isContainer}}{{/isNullable}}{{/required}}{{/useOptional}}{{name}}{{#isNullable}}){{/isNullable}}{{#useOptional}}{{^required}}{{^isNullable}}{{^isContainer}}){{/isContainer}}{{/isNullable}}{{/required}}{{/useOptional}};
     {{/openApiNullable}}
     {{^openApiNullable}}
     this.{{name}} = {{name}};
@@ -203,7 +203,7 @@ public class {{classname}}{{#parent}} extends {{{parent}}}{{/parent}}{{^parent}}
   {{#deprecated}}
   @Deprecated
   {{/deprecated}}
-  public {{>nullableDataType}} {{getter}}() {
+  public {{>nullableDataTypeBeanValidation}} {{getter}}() {
     return {{name}};
   }
 

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/assertions/MethodAssert.java

@@ -54,6 +54,13 @@ public class MethodAssert extends AbstractAssert<MethodAssert, MethodDeclaration
         return this;
     }
 
+    public MethodAssert doesNotHaveParameters() {
+        Assertions.assertThat(actual.getParameters())
+                .withFailMessage("Method %s shouldn't have parameter, but it does", methodSignature)
+                .isEmpty();
+        return this;
+    }
+
     public MethodAssert bodyContainsLines(final String... lines) {
         Assertions.assertThat(isWithImplementation())
             .withFailMessage("Method %s is abstract", methodSignature)

modules/openapi-generator/src/test/resources/3_0/issue_14765.yaml

@@ -0,0 +1,166 @@
+openapi: 3.0.0
+servers:
+  - url: 'localhost:8080'
+info:
+  version: 1.0.0
+  title: OpenAPI Zoo
+  license:
+    name: Apache-2.0
+    url: 'https://www.apache.org/licenses/LICENSE-2.0.html'
+paths:
+  /zebras:
+    get:
+      operationId: getZebras
+      responses:
+        '200':
+          description: OK
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Animal'
+
+components:
+  schemas:
+    Zebra:
+      required:
+        - name
+        - age
+      type: object
+      properties:
+        name:
+          type: string
+          example: 'Marty'
+        age:
+          type: integer
+          example: 15
+          nullable: true
+    Animal:
+      required: 
+        - name
+        - age
+      type: object
+      properties:
+        name:
+          type: string
+          example: 'Marty'
+        age:
+          type: integer
+          example: 15
+          nullable: true
+        alias:
+          type: string
+          nullable: true
+          description: 'The stripy one'
+          example: 'Stripy'
+        color:
+          type: string
+          description: 'The color'
+          example: 'red'
+
+        names:
+          type: array
+          items:
+            type: string
+        colors:
+          type: array
+          nullable: true
+          items:
+            type: string
+
+        stringPattern:
+            type: string
+            pattern: "[a-z]"
+        stringMaxMinLength:
+            type: string
+            minLength: 1
+            maxLength: 10
+        stringMinLength:
+            type: string
+            minLength: 1
+        stringMaxLength:
+            type: string
+            maxLength: 1
+        stringEmail:
+            type: string
+            format: email
+        intMinMax:
+            type: integer
+            minimum: 1
+            maximum: 10
+        intMin:
+            type: integer
+            minimum: 1
+        intMax:
+            type: integer
+            maximum: 10
+        numberMinMax:
+            type: number
+            minimum: 1
+            maximum: 10
+        numberMin:
+            type: number
+            minimum: 1
+        numberMax:
+            type: number
+            maximum: 10
+        stringDefault:
+          type: string
+          maxLength: 1
+          default: "ABC"
+        zebra:
+          $ref: '#/components/schemas/Zebra'
+
+        stringPatternNullable:
+          nullable: true
+          type: string
+          pattern: "[a-z]"
+        stringMaxMinLengthNullable:
+          nullable: true
+          type: string
+          minLength: 1
+          maxLength: 10
+        stringMinLengthNullable:
+          nullable: true
+          type: string
+          minLength: 1
+        stringMaxLengthNullable:
+          nullable: true
+          type: string
+          maxLength: 1
+        stringEmailNullable:
+          nullable: true
+          type: string
+          format: email
+        intMinMaxNullable:
+          nullable: true
+          type: integer
+          minimum: 1
+          maximum: 10
+        intMinNullable:
+          nullable: true
+          type: integer
+          minimum: 1
+        intMaxNullable:
+          nullable: true
+          type: integer
+          maximum: 10
+        numberMinMaxNullable:
+          nullable: true
+          type: number
+          minimum: 1
+          maximum: 10
+        numberMinNullable:
+          nullable: true
+          type: number
+          minimum: 1
+        numberMaxNullable:
+          nullable: true
+          type: number
+          maximum: 10
+        stringDefaultNullable:
+          type: string
+          nullable: true
+          maxLength: 1
+          default: "ABC"

samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Category.java

@@ -20,12 +20,12 @@ import jakarta.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Category {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private String name;
+  private Optional<@Pattern(regexp = "^[a-zA-Z0-9]+[a-zA-Z0-9\\.\\-_]*[a-zA-Z0-9]+$") String> name = Optional.empty();
 
   public Category id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -35,16 +35,16 @@ public class Category {
   */
   
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public Category name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -52,13 +52,13 @@ public class Category {
    * Get name
    * @return name
   */
-  @Pattern(regexp = "^[a-zA-Z0-9]+[a-zA-Z0-9\\.\\-_]*[a-zA-Z0-9]+$") 
+  
   @JsonProperty("name")
-  public String getName() {
+  public Optional<@Pattern(regexp = "^[a-zA-Z0-9]+[a-zA-Z0-9\\.\\-_]*[a-zA-Z0-9]+$") String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
 

samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/ModelApiResponse.java

@@ -22,14 +22,14 @@ import jakarta.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class ModelApiResponse {
 
-  private Integer code;
+  private Optional<Integer> code = Optional.empty();
 
-  private String type;
+  private Optional<String> type = Optional.empty();
 
-  private String message;
+  private Optional<String> message = Optional.empty();
 
   public ModelApiResponse code(Integer code) {
-    this.code = code;
+    this.code = Optional.of(code);
     return this;
   }
 
@@ -39,16 +39,16 @@ public class ModelApiResponse {
   */
   
   @JsonProperty("code")
-  public Integer getCode() {
+  public Optional<Integer> getCode() {
     return code;
   }
 
-  public void setCode(Integer code) {
+  public void setCode(Optional<Integer> code) {
     this.code = code;
   }
 
   public ModelApiResponse type(String type) {
-    this.type = type;
+    this.type = Optional.of(type);
     return this;
   }
 
@@ -58,16 +58,16 @@ public class ModelApiResponse {
   */
   
   @JsonProperty("type")
-  public String getType() {
+  public Optional<String> getType() {
     return type;
   }
 
-  public void setType(String type) {
+  public void setType(Optional<String> type) {
     this.type = type;
   }
 
   public ModelApiResponse message(String message) {
-    this.message = message;
+    this.message = Optional.of(message);
     return this;
   }
 
@@ -77,11 +77,11 @@ public class ModelApiResponse {
   */
   
   @JsonProperty("message")
-  public String getMessage() {
+  public Optional<String> getMessage() {
     return message;
   }
 
-  public void setMessage(String message) {
+  public void setMessage(Optional<String> message) {
     this.message = message;
   }
 

samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Order.java

@@ -23,14 +23,14 @@ import jakarta.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Order {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private Long petId;
+  private Optional<Long> petId = Optional.empty();
 
-  private Integer quantity;
+  private Optional<Integer> quantity = Optional.empty();
 
   @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
-  private OffsetDateTime shipDate;
+  private Optional<OffsetDateTime> shipDate = Optional.empty();
 
   /**
    * Order Status
@@ -69,12 +69,12 @@ public class Order {
     }
   }
 
-  private StatusEnum status;
+  private Optional<StatusEnum> status = Optional.empty();
 
-  private Boolean complete = false;
+  private Optional<Boolean> complete = Optional.of(false);
 
   public Order id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -84,16 +84,16 @@ public class Order {
   */
   
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public Order petId(Long petId) {
-    this.petId = petId;
+    this.petId = Optional.of(petId);
     return this;
   }
 
@@ -103,16 +103,16 @@ public class Order {
   */
   
   @JsonProperty("petId")
-  public Long getPetId() {
+  public Optional<Long> getPetId() {
     return petId;
   }
 
-  public void setPetId(Long petId) {
+  public void setPetId(Optional<Long> petId) {
     this.petId = petId;
   }
 
   public Order quantity(Integer quantity) {
-    this.quantity = quantity;
+    this.quantity = Optional.of(quantity);
     return this;
   }
 
@@ -122,16 +122,16 @@ public class Order {
   */
   
   @JsonProperty("quantity")
-  public Integer getQuantity() {
+  public Optional<Integer> getQuantity() {
     return quantity;
   }
 
-  public void setQuantity(Integer quantity) {
+  public void setQuantity(Optional<Integer> quantity) {
     this.quantity = quantity;
   }
 
   public Order shipDate(OffsetDateTime shipDate) {
-    this.shipDate = shipDate;
+    this.shipDate = Optional.of(shipDate);
     return this;
   }
 
@@ -141,16 +141,16 @@ public class Order {
   */
   @Valid 
   @JsonProperty("shipDate")
-  public OffsetDateTime getShipDate() {
+  public Optional<OffsetDateTime> getShipDate() {
     return shipDate;
   }
 
-  public void setShipDate(OffsetDateTime shipDate) {
+  public void setShipDate(Optional<OffsetDateTime> shipDate) {
     this.shipDate = shipDate;
   }
 
   public Order status(StatusEnum status) {
-    this.status = status;
+    this.status = Optional.of(status);
     return this;
   }
 
@@ -160,16 +160,16 @@ public class Order {
   */
   
   @JsonProperty("status")
-  public StatusEnum getStatus() {
+  public Optional<StatusEnum> getStatus() {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(Optional<StatusEnum> status) {
     this.status = status;
   }
 
   public Order complete(Boolean complete) {
-    this.complete = complete;
+    this.complete = Optional.of(complete);
     return this;
   }
 
@@ -179,11 +179,11 @@ public class Order {
   */
   
   @JsonProperty("complete")
-  public Boolean getComplete() {
+  public Optional<Boolean> getComplete() {
     return complete;
   }
 
-  public void setComplete(Boolean complete) {
+  public void setComplete(Optional<Boolean> complete) {
     this.complete = complete;
   }
 

samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Pet.java

@@ -26,9 +26,9 @@ import jakarta.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Pet {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private Category category;
+  private Optional<Category> category = Optional.empty();
 
   private String name;
 
@@ -76,7 +76,7 @@ public class Pet {
   }
 
   @Deprecated
-  private StatusEnum status;
+  private Optional<StatusEnum> status = Optional.empty();
 
   public Pet() {
     super();
@@ -91,7 +91,7 @@ public class Pet {
   }
 
   public Pet id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -101,16 +101,16 @@ public class Pet {
   */
   
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public Pet category(Category category) {
-    this.category = category;
+    this.category = Optional.of(category);
     return this;
   }
 
@@ -120,11 +120,11 @@ public class Pet {
   */
   @Valid 
   @JsonProperty("category")
-  public Category getCategory() {
+  public Optional<Category> getCategory() {
     return category;
   }
 
-  public void setCategory(Category category) {
+  public void setCategory(Optional<Category> category) {
     this.category = category;
   }
 
@@ -202,7 +202,7 @@ public class Pet {
   }
 
   public Pet status(StatusEnum status) {
-    this.status = status;
+    this.status = Optional.of(status);
     return this;
   }
 
@@ -214,7 +214,7 @@ public class Pet {
   
   @JsonProperty("status")
   @Deprecated
-  public StatusEnum getStatus() {
+  public Optional<StatusEnum> getStatus() {
     return status;
   }
 
@@ -222,7 +222,7 @@ public class Pet {
    * @deprecated
   */
   @Deprecated
-  public void setStatus(StatusEnum status) {
+  public void setStatus(Optional<StatusEnum> status) {
     this.status = status;
   }
 

samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/Tag.java

@@ -20,12 +20,12 @@ import jakarta.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Tag {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public Tag id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -35,16 +35,16 @@ public class Tag {
   */
   
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public Tag name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -54,11 +54,11 @@ public class Tag {
   */
   
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
 

samples/openapi3/client/petstore/spring-cloud-3-with-optional/src/main/java/org/openapitools/model/User.java

@@ -20,24 +20,24 @@ import jakarta.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class User {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private String username;
+  private Optional<String> username = Optional.empty();
 
-  private String firstName;
+  private Optional<String> firstName = Optional.empty();
 
-  private String lastName;
+  private Optional<String> lastName = Optional.empty();
 
-  private String email;
+  private Optional<String> email = Optional.empty();
 
-  private String password;
+  private Optional<String> password = Optional.empty();
 
-  private String phone;
+  private Optional<String> phone = Optional.empty();
 
-  private Integer userStatus;
+  private Optional<Integer> userStatus = Optional.empty();
 
   public User id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -47,16 +47,16 @@ public class User {
   */
   
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public User username(String username) {
-    this.username = username;
+    this.username = Optional.of(username);
     return this;
   }
 
@@ -66,16 +66,16 @@ public class User {
   */
   
   @JsonProperty("username")
-  public String getUsername() {
+  public Optional<String> getUsername() {
     return username;
   }
 
-  public void setUsername(String username) {
+  public void setUsername(Optional<String> username) {
     this.username = username;
   }
 
   public User firstName(String firstName) {
-    this.firstName = firstName;
+    this.firstName = Optional.of(firstName);
     return this;
   }
 
@@ -85,16 +85,16 @@ public class User {
   */
   
   @JsonProperty("firstName")
-  public String getFirstName() {
+  public Optional<String> getFirstName() {
     return firstName;
   }
 
-  public void setFirstName(String firstName) {
+  public void setFirstName(Optional<String> firstName) {
     this.firstName = firstName;
   }
 
   public User lastName(String lastName) {
-    this.lastName = lastName;
+    this.lastName = Optional.of(lastName);
     return this;
   }
 
@@ -104,16 +104,16 @@ public class User {
   */
   
   @JsonProperty("lastName")
-  public String getLastName() {
+  public Optional<String> getLastName() {
     return lastName;
   }
 
-  public void setLastName(String lastName) {
+  public void setLastName(Optional<String> lastName) {
     this.lastName = lastName;
   }
 
   public User email(String email) {
-    this.email = email;
+    this.email = Optional.of(email);
     return this;
   }
 
@@ -123,16 +123,16 @@ public class User {
   */
   
   @JsonProperty("email")
-  public String getEmail() {
+  public Optional<String> getEmail() {
     return email;
   }
 
-  public void setEmail(String email) {
+  public void setEmail(Optional<String> email) {
     this.email = email;
   }
 
   public User password(String password) {
-    this.password = password;
+    this.password = Optional.of(password);
     return this;
   }
 
@@ -142,16 +142,16 @@ public class User {
   */
   
   @JsonProperty("password")
-  public String getPassword() {
+  public Optional<String> getPassword() {
     return password;
   }
 
-  public void setPassword(String password) {
+  public void setPassword(Optional<String> password) {
     this.password = password;
   }
 
   public User phone(String phone) {
-    this.phone = phone;
+    this.phone = Optional.of(phone);
     return this;
   }
 
@@ -161,16 +161,16 @@ public class User {
   */
   
   @JsonProperty("phone")
-  public String getPhone() {
+  public Optional<String> getPhone() {
     return phone;
   }
 
-  public void setPhone(String phone) {
+  public void setPhone(Optional<String> phone) {
     this.phone = phone;
   }
 
   public User userStatus(Integer userStatus) {
-    this.userStatus = userStatus;
+    this.userStatus = Optional.of(userStatus);
     return this;
   }
 
@@ -180,11 +180,11 @@ public class User {
   */
   
   @JsonProperty("userStatus")
-  public Integer getUserStatus() {
+  public Optional<Integer> getUserStatus() {
     return userStatus;
   }
 
-  public void setUserStatus(Integer userStatus) {
+  public void setUserStatus(Optional<Integer> userStatus) {
     this.userStatus = userStatus;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesAnyType.java

@@ -26,10 +26,10 @@ import com.fasterxml.jackson.annotation.JsonAnySetter;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class AdditionalPropertiesAnyType {
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public AdditionalPropertiesAnyType name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -40,11 +40,11 @@ public class AdditionalPropertiesAnyType {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
     /**

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesArray.java

@@ -27,10 +27,10 @@ import com.fasterxml.jackson.annotation.JsonAnySetter;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class AdditionalPropertiesArray {
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public AdditionalPropertiesArray name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -41,11 +41,11 @@ public class AdditionalPropertiesArray {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
     /**

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesBoolean.java

@@ -26,10 +26,10 @@ import com.fasterxml.jackson.annotation.JsonAnySetter;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class AdditionalPropertiesBoolean {
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public AdditionalPropertiesBoolean name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -40,11 +40,11 @@ public class AdditionalPropertiesBoolean {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
     /**

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesClass.java

@@ -53,11 +53,11 @@ public class AdditionalPropertiesClass {
   @Valid
   private Map<String, Map<String, Object>> mapMapAnytype = new HashMap<>();
 
-  private Object anytype1;
+  private Optional<Object> anytype1 = Optional.empty();
 
   private JsonNullable<Object> anytype2 = JsonNullable.<Object>undefined();
 
-  private Object anytype3;
+  private Optional<Object> anytype3 = Optional.empty();
 
   public AdditionalPropertiesClass mapString(Map<String, String> mapString) {
     this.mapString = mapString;
@@ -284,7 +284,7 @@ public class AdditionalPropertiesClass {
   }
 
   public AdditionalPropertiesClass anytype1(Object anytype1) {
-    this.anytype1 = anytype1;
+    this.anytype1 = Optional.of(anytype1);
     return this;
   }
 
@@ -295,11 +295,11 @@ public class AdditionalPropertiesClass {
   
   @ApiModelProperty(value = "")
   @JsonProperty("anytype_1")
-  public Object getAnytype1() {
+  public Optional<Object> getAnytype1() {
     return anytype1;
   }
 
-  public void setAnytype1(Object anytype1) {
+  public void setAnytype1(Optional<Object> anytype1) {
     this.anytype1 = anytype1;
   }
 
@@ -324,7 +324,7 @@ public class AdditionalPropertiesClass {
   }
 
   public AdditionalPropertiesClass anytype3(Object anytype3) {
-    this.anytype3 = anytype3;
+    this.anytype3 = Optional.of(anytype3);
     return this;
   }
 
@@ -335,11 +335,11 @@ public class AdditionalPropertiesClass {
   
   @ApiModelProperty(value = "")
   @JsonProperty("anytype_3")
-  public Object getAnytype3() {
+  public Optional<Object> getAnytype3() {
     return anytype3;
   }
 
-  public void setAnytype3(Object anytype3) {
+  public void setAnytype3(Optional<Object> anytype3) {
     this.anytype3 = anytype3;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesInteger.java

@@ -26,10 +26,10 @@ import com.fasterxml.jackson.annotation.JsonAnySetter;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class AdditionalPropertiesInteger {
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public AdditionalPropertiesInteger name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -40,11 +40,11 @@ public class AdditionalPropertiesInteger {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
     /**

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesNumber.java

@@ -27,10 +27,10 @@ import com.fasterxml.jackson.annotation.JsonAnySetter;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class AdditionalPropertiesNumber {
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public AdditionalPropertiesNumber name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -41,11 +41,11 @@ public class AdditionalPropertiesNumber {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
     /**

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesObject.java

@@ -27,10 +27,10 @@ import com.fasterxml.jackson.annotation.JsonAnySetter;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class AdditionalPropertiesObject {
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public AdditionalPropertiesObject name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -41,11 +41,11 @@ public class AdditionalPropertiesObject {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
     /**

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/AdditionalPropertiesString.java

@@ -26,10 +26,10 @@ import com.fasterxml.jackson.annotation.JsonAnySetter;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class AdditionalPropertiesString {
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public AdditionalPropertiesString name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -40,11 +40,11 @@ public class AdditionalPropertiesString {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
     /**

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Animal.java

@@ -38,7 +38,7 @@ public class Animal {
 
   private String className;
 
-  private String color = "red";
+  private Optional<String> color = Optional.of("red");
 
   public Animal() {
     super();
@@ -72,7 +72,7 @@ public class Animal {
   }
 
   public Animal color(String color) {
-    this.color = color;
+    this.color = Optional.of(color);
     return this;
   }
 
@@ -83,11 +83,11 @@ public class Animal {
   
   @ApiModelProperty(value = "")
   @JsonProperty("color")
-  public String getColor() {
+  public Optional<String> getColor() {
     return color;
   }
 
-  public void setColor(String color) {
+  public void setColor(Optional<String> color) {
     this.color = color;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/BigCat.java

@@ -67,7 +67,7 @@ public class BigCat extends Cat {
     }
   }
 
-  private KindEnum kind;
+  private Optional<KindEnum> kind = Optional.empty();
 
   public BigCat() {
     super();
@@ -81,7 +81,7 @@ public class BigCat extends Cat {
   }
 
   public BigCat kind(KindEnum kind) {
-    this.kind = kind;
+    this.kind = Optional.of(kind);
     return this;
   }
 
@@ -92,11 +92,11 @@ public class BigCat extends Cat {
   
   @ApiModelProperty(value = "")
   @JsonProperty("kind")
-  public KindEnum getKind() {
+  public Optional<KindEnum> getKind() {
     return kind;
   }
 
-  public void setKind(KindEnum kind) {
+  public void setKind(Optional<KindEnum> kind) {
     this.kind = kind;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Capitalization.java

@@ -22,20 +22,20 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Capitalization {
 
-  private String smallCamel;
+  private Optional<String> smallCamel = Optional.empty();
 
-  private String capitalCamel;
+  private Optional<String> capitalCamel = Optional.empty();
 
-  private String smallSnake;
+  private Optional<String> smallSnake = Optional.empty();
 
-  private String capitalSnake;
+  private Optional<String> capitalSnake = Optional.empty();
 
-  private String scAETHFlowPoints;
+  private Optional<String> scAETHFlowPoints = Optional.empty();
 
-  private String ATT_NAME;
+  private Optional<String> ATT_NAME = Optional.empty();
 
   public Capitalization smallCamel(String smallCamel) {
-    this.smallCamel = smallCamel;
+    this.smallCamel = Optional.of(smallCamel);
     return this;
   }
 
@@ -46,16 +46,16 @@ public class Capitalization {
   
   @ApiModelProperty(value = "")
   @JsonProperty("smallCamel")
-  public String getSmallCamel() {
+  public Optional<String> getSmallCamel() {
     return smallCamel;
   }
 
-  public void setSmallCamel(String smallCamel) {
+  public void setSmallCamel(Optional<String> smallCamel) {
     this.smallCamel = smallCamel;
   }
 
   public Capitalization capitalCamel(String capitalCamel) {
-    this.capitalCamel = capitalCamel;
+    this.capitalCamel = Optional.of(capitalCamel);
     return this;
   }
 
@@ -66,16 +66,16 @@ public class Capitalization {
   
   @ApiModelProperty(value = "")
   @JsonProperty("CapitalCamel")
-  public String getCapitalCamel() {
+  public Optional<String> getCapitalCamel() {
     return capitalCamel;
   }
 
-  public void setCapitalCamel(String capitalCamel) {
+  public void setCapitalCamel(Optional<String> capitalCamel) {
     this.capitalCamel = capitalCamel;
   }
 
   public Capitalization smallSnake(String smallSnake) {
-    this.smallSnake = smallSnake;
+    this.smallSnake = Optional.of(smallSnake);
     return this;
   }
 
@@ -86,16 +86,16 @@ public class Capitalization {
   
   @ApiModelProperty(value = "")
   @JsonProperty("small_Snake")
-  public String getSmallSnake() {
+  public Optional<String> getSmallSnake() {
     return smallSnake;
   }
 
-  public void setSmallSnake(String smallSnake) {
+  public void setSmallSnake(Optional<String> smallSnake) {
     this.smallSnake = smallSnake;
   }
 
   public Capitalization capitalSnake(String capitalSnake) {
-    this.capitalSnake = capitalSnake;
+    this.capitalSnake = Optional.of(capitalSnake);
     return this;
   }
 
@@ -106,16 +106,16 @@ public class Capitalization {
   
   @ApiModelProperty(value = "")
   @JsonProperty("Capital_Snake")
-  public String getCapitalSnake() {
+  public Optional<String> getCapitalSnake() {
     return capitalSnake;
   }
 
-  public void setCapitalSnake(String capitalSnake) {
+  public void setCapitalSnake(Optional<String> capitalSnake) {
     this.capitalSnake = capitalSnake;
   }
 
   public Capitalization scAETHFlowPoints(String scAETHFlowPoints) {
-    this.scAETHFlowPoints = scAETHFlowPoints;
+    this.scAETHFlowPoints = Optional.of(scAETHFlowPoints);
     return this;
   }
 
@@ -126,16 +126,16 @@ public class Capitalization {
   
   @ApiModelProperty(value = "")
   @JsonProperty("SCA_ETH_Flow_Points")
-  public String getScAETHFlowPoints() {
+  public Optional<String> getScAETHFlowPoints() {
     return scAETHFlowPoints;
   }
 
-  public void setScAETHFlowPoints(String scAETHFlowPoints) {
+  public void setScAETHFlowPoints(Optional<String> scAETHFlowPoints) {
     this.scAETHFlowPoints = scAETHFlowPoints;
   }
 
   public Capitalization ATT_NAME(String ATT_NAME) {
-    this.ATT_NAME = ATT_NAME;
+    this.ATT_NAME = Optional.of(ATT_NAME);
     return this;
   }
 
@@ -146,11 +146,11 @@ public class Capitalization {
   
   @ApiModelProperty(value = "Name of the pet ")
   @JsonProperty("ATT_NAME")
-  public String getATTNAME() {
+  public Optional<String> getATTNAME() {
     return ATT_NAME;
   }
 
-  public void setATTNAME(String ATT_NAME) {
+  public void setATTNAME(Optional<String> ATT_NAME) {
     this.ATT_NAME = ATT_NAME;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Cat.java

@@ -35,7 +35,7 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Cat extends Animal {
 
-  private Boolean declawed;
+  private Optional<Boolean> declawed = Optional.empty();
 
   public Cat() {
     super();
@@ -49,7 +49,7 @@ public class Cat extends Animal {
   }
 
   public Cat declawed(Boolean declawed) {
-    this.declawed = declawed;
+    this.declawed = Optional.of(declawed);
     return this;
   }
 
@@ -60,11 +60,11 @@ public class Cat extends Animal {
   
   @ApiModelProperty(value = "")
   @JsonProperty("declawed")
-  public Boolean getDeclawed() {
+  public Optional<Boolean> getDeclawed() {
     return declawed;
   }
 
-  public void setDeclawed(Boolean declawed) {
+  public void setDeclawed(Optional<Boolean> declawed) {
     this.declawed = declawed;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Category.java

@@ -22,7 +22,7 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Category {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
   private String name = "default-name";
 
@@ -38,7 +38,7 @@ public class Category {
   }
 
   public Category id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -49,11 +49,11 @@ public class Category {
   
   @ApiModelProperty(value = "")
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ChildWithNullable.java

@@ -30,10 +30,10 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class ChildWithNullable extends ParentWithNullable {
 
-  private String otherProperty;
+  private Optional<String> otherProperty = Optional.empty();
 
   public ChildWithNullable otherProperty(String otherProperty) {
-    this.otherProperty = otherProperty;
+    this.otherProperty = Optional.of(otherProperty);
     return this;
   }
 
@@ -44,11 +44,11 @@ public class ChildWithNullable extends ParentWithNullable {
   
   @ApiModelProperty(value = "")
   @JsonProperty("otherProperty")
-  public String getOtherProperty() {
+  public Optional<String> getOtherProperty() {
     return otherProperty;
   }
 
-  public void setOtherProperty(String otherProperty) {
+  public void setOtherProperty(Optional<String> otherProperty) {
     this.otherProperty = otherProperty;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ClassModel.java

@@ -23,10 +23,10 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class ClassModel {
 
-  private String propertyClass;
+  private Optional<String> propertyClass = Optional.empty();
 
   public ClassModel propertyClass(String propertyClass) {
-    this.propertyClass = propertyClass;
+    this.propertyClass = Optional.of(propertyClass);
     return this;
   }
 
@@ -37,11 +37,11 @@ public class ClassModel {
   
   @ApiModelProperty(value = "")
   @JsonProperty("_class")
-  public String getPropertyClass() {
+  public Optional<String> getPropertyClass() {
     return propertyClass;
   }
 
-  public void setPropertyClass(String propertyClass) {
+  public void setPropertyClass(Optional<String> propertyClass) {
     this.propertyClass = propertyClass;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Client.java

@@ -22,10 +22,10 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Client {
 
-  private String client;
+  private Optional<String> client = Optional.empty();
 
   public Client client(String client) {
-    this.client = client;
+    this.client = Optional.of(client);
     return this;
   }
 
@@ -36,11 +36,11 @@ public class Client {
   
   @ApiModelProperty(value = "")
   @JsonProperty("client")
-  public String getClient() {
+  public Optional<String> getClient() {
     return client;
   }
 
-  public void setClient(String client) {
+  public void setClient(Optional<String> client) {
     this.client = client;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Dog.java

@@ -27,7 +27,7 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Dog extends Animal {
 
-  private String breed;
+  private Optional<String> breed = Optional.empty();
 
   public Dog() {
     super();
@@ -41,7 +41,7 @@ public class Dog extends Animal {
   }
 
   public Dog breed(String breed) {
-    this.breed = breed;
+    this.breed = Optional.of(breed);
     return this;
   }
 
@@ -52,11 +52,11 @@ public class Dog extends Animal {
   
   @ApiModelProperty(value = "")
   @JsonProperty("breed")
-  public String getBreed() {
+  public Optional<String> getBreed() {
     return breed;
   }
 
-  public void setBreed(String breed) {
+  public void setBreed(Optional<String> breed) {
     this.breed = breed;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumArrays.java

@@ -61,7 +61,7 @@ public class EnumArrays {
     }
   }
 
-  private JustSymbolEnum justSymbol;
+  private Optional<JustSymbolEnum> justSymbol = Optional.empty();
 
   /**
    * Gets or Sets arrayEnum
@@ -102,7 +102,7 @@ public class EnumArrays {
   private List<ArrayEnumEnum> arrayEnum;
 
   public EnumArrays justSymbol(JustSymbolEnum justSymbol) {
-    this.justSymbol = justSymbol;
+    this.justSymbol = Optional.of(justSymbol);
     return this;
   }
 
@@ -113,11 +113,11 @@ public class EnumArrays {
   
   @ApiModelProperty(value = "")
   @JsonProperty("just_symbol")
-  public JustSymbolEnum getJustSymbol() {
+  public Optional<JustSymbolEnum> getJustSymbol() {
     return justSymbol;
   }
 
-  public void setJustSymbol(JustSymbolEnum justSymbol) {
+  public void setJustSymbol(Optional<JustSymbolEnum> justSymbol) {
     this.justSymbol = justSymbol;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/EnumTest.java

@@ -63,7 +63,7 @@ public class EnumTest {
     }
   }
 
-  private EnumStringEnum enumString;
+  private Optional<EnumStringEnum> enumString = Optional.empty();
 
   /**
    * Gets or Sets enumStringRequired
@@ -139,7 +139,7 @@ public class EnumTest {
     }
   }
 
-  private EnumIntegerEnum enumInteger;
+  private Optional<EnumIntegerEnum> enumInteger = Optional.empty();
 
   /**
    * Gets or Sets enumNumber
@@ -176,9 +176,9 @@ public class EnumTest {
     }
   }
 
-  private EnumNumberEnum enumNumber;
+  private Optional<EnumNumberEnum> enumNumber = Optional.empty();
 
-  private OuterEnum outerEnum;
+  private Optional<OuterEnum> outerEnum = Optional.empty();
 
   public EnumTest() {
     super();
@@ -192,7 +192,7 @@ public class EnumTest {
   }
 
   public EnumTest enumString(EnumStringEnum enumString) {
-    this.enumString = enumString;
+    this.enumString = Optional.of(enumString);
     return this;
   }
 
@@ -203,11 +203,11 @@ public class EnumTest {
   
   @ApiModelProperty(value = "")
   @JsonProperty("enum_string")
-  public EnumStringEnum getEnumString() {
+  public Optional<EnumStringEnum> getEnumString() {
     return enumString;
   }
 
-  public void setEnumString(EnumStringEnum enumString) {
+  public void setEnumString(Optional<EnumStringEnum> enumString) {
     this.enumString = enumString;
   }
 
@@ -232,7 +232,7 @@ public class EnumTest {
   }
 
   public EnumTest enumInteger(EnumIntegerEnum enumInteger) {
-    this.enumInteger = enumInteger;
+    this.enumInteger = Optional.of(enumInteger);
     return this;
   }
 
@@ -243,16 +243,16 @@ public class EnumTest {
   
   @ApiModelProperty(value = "")
   @JsonProperty("enum_integer")
-  public EnumIntegerEnum getEnumInteger() {
+  public Optional<EnumIntegerEnum> getEnumInteger() {
     return enumInteger;
   }
 
-  public void setEnumInteger(EnumIntegerEnum enumInteger) {
+  public void setEnumInteger(Optional<EnumIntegerEnum> enumInteger) {
     this.enumInteger = enumInteger;
   }
 
   public EnumTest enumNumber(EnumNumberEnum enumNumber) {
-    this.enumNumber = enumNumber;
+    this.enumNumber = Optional.of(enumNumber);
     return this;
   }
 
@@ -263,16 +263,16 @@ public class EnumTest {
   
   @ApiModelProperty(value = "")
   @JsonProperty("enum_number")
-  public EnumNumberEnum getEnumNumber() {
+  public Optional<EnumNumberEnum> getEnumNumber() {
     return enumNumber;
   }
 
-  public void setEnumNumber(EnumNumberEnum enumNumber) {
+  public void setEnumNumber(Optional<EnumNumberEnum> enumNumber) {
     this.enumNumber = enumNumber;
   }
 
   public EnumTest outerEnum(OuterEnum outerEnum) {
-    this.outerEnum = outerEnum;
+    this.outerEnum = Optional.of(outerEnum);
     return this;
   }
 
@@ -283,11 +283,11 @@ public class EnumTest {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("outerEnum")
-  public OuterEnum getOuterEnum() {
+  public Optional<OuterEnum> getOuterEnum() {
     return outerEnum;
   }
 
-  public void setOuterEnum(OuterEnum outerEnum) {
+  public void setOuterEnum(Optional<OuterEnum> outerEnum) {
     this.outerEnum = outerEnum;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/File.java

@@ -23,10 +23,10 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class File {
 
-  private String sourceURI;
+  private Optional<String> sourceURI = Optional.empty();
 
   public File sourceURI(String sourceURI) {
-    this.sourceURI = sourceURI;
+    this.sourceURI = Optional.of(sourceURI);
     return this;
   }
 
@@ -37,11 +37,11 @@ public class File {
   
   @ApiModelProperty(value = "Test capitalization")
   @JsonProperty("sourceURI")
-  public String getSourceURI() {
+  public Optional<String> getSourceURI() {
     return sourceURI;
   }
 
-  public void setSourceURI(String sourceURI) {
+  public void setSourceURI(Optional<String> sourceURI) {
     this.sourceURI = sourceURI;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FileSchemaTestClass.java

@@ -26,13 +26,13 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class FileSchemaTestClass {
 
-  private File file;
+  private Optional<File> file = Optional.empty();
 
   @Valid
   private List<@Valid File> files;
 
   public FileSchemaTestClass file(File file) {
-    this.file = file;
+    this.file = Optional.of(file);
     return this;
   }
 
@@ -43,11 +43,11 @@ public class FileSchemaTestClass {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("file")
-  public File getFile() {
+  public Optional<File> getFile() {
     return file;
   }
 
-  public void setFile(File file) {
+  public void setFile(Optional<File> file) {
     this.file = file;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/FormatTest.java

@@ -30,35 +30,35 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class FormatTest {
 
-  private Integer integer;
+  private Optional<@Min(10) @Max(100) Integer> integer = Optional.empty();
 
-  private Integer int32;
+  private Optional<@Min(20) @Max(200) Integer> int32 = Optional.empty();
 
-  private Long int64;
+  private Optional<Long> int64 = Optional.empty();
 
   private BigDecimal number;
 
-  private Float _float;
+  private Optional<@DecimalMin("54.3") @DecimalMax("987.6") Float> _float = Optional.empty();
 
-  private Double _double;
+  private Optional<@DecimalMin("67.8") @DecimalMax("123.4") Double> _double = Optional.empty();
 
-  private String string;
+  private Optional<@Pattern(regexp = "/[a-z]/i") String> string = Optional.empty();
 
   private byte[] _byte;
 
-  private org.springframework.core.io.Resource binary;
+  private Optional<org.springframework.core.io.Resource> binary = Optional.empty();
 
   @DateTimeFormat(iso = DateTimeFormat.ISO.DATE)
   private LocalDate date;
 
   @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
-  private OffsetDateTime dateTime;
+  private Optional<OffsetDateTime> dateTime = Optional.empty();
 
-  private UUID uuid;
+  private Optional<UUID> uuid = Optional.empty();
 
   private String password;
 
-  private BigDecimal bigDecimal;
+  private Optional<BigDecimal> bigDecimal = Optional.empty();
 
   public FormatTest() {
     super();
@@ -75,7 +75,7 @@ public class FormatTest {
   }
 
   public FormatTest integer(Integer integer) {
-    this.integer = integer;
+    this.integer = Optional.of(integer);
     return this;
   }
 
@@ -85,19 +85,19 @@ public class FormatTest {
    * maximum: 100
    * @return integer
   */
-  @Min(10) @Max(100) 
+  
   @ApiModelProperty(value = "")
   @JsonProperty("integer")
-  public Integer getInteger() {
+  public Optional<@Min(10) @Max(100) Integer> getInteger() {
     return integer;
   }
 
-  public void setInteger(Integer integer) {
+  public void setInteger(Optional<Integer> integer) {
     this.integer = integer;
   }
 
   public FormatTest int32(Integer int32) {
-    this.int32 = int32;
+    this.int32 = Optional.of(int32);
     return this;
   }
 
@@ -107,19 +107,19 @@ public class FormatTest {
    * maximum: 200
    * @return int32
   */
-  @Min(20) @Max(200) 
+  
   @ApiModelProperty(value = "")
   @JsonProperty("int32")
-  public Integer getInt32() {
+  public Optional<@Min(20) @Max(200) Integer> getInt32() {
     return int32;
   }
 
-  public void setInt32(Integer int32) {
+  public void setInt32(Optional<Integer> int32) {
     this.int32 = int32;
   }
 
   public FormatTest int64(Long int64) {
-    this.int64 = int64;
+    this.int64 = Optional.of(int64);
     return this;
   }
 
@@ -130,11 +130,11 @@ public class FormatTest {
   
   @ApiModelProperty(value = "")
   @JsonProperty("int64")
-  public Long getInt64() {
+  public Optional<Long> getInt64() {
     return int64;
   }
 
-  public void setInt64(Long int64) {
+  public void setInt64(Optional<Long> int64) {
     this.int64 = int64;
   }
 
@@ -161,7 +161,7 @@ public class FormatTest {
   }
 
   public FormatTest _float(Float _float) {
-    this._float = _float;
+    this._float = Optional.of(_float);
     return this;
   }
 
@@ -171,19 +171,19 @@ public class FormatTest {
    * maximum: 987.6
    * @return _float
   */
-  @DecimalMin("54.3") @DecimalMax("987.6") 
+  
   @ApiModelProperty(value = "")
   @JsonProperty("float")
-  public Float getFloat() {
+  public Optional<@DecimalMin("54.3") @DecimalMax("987.6") Float> getFloat() {
     return _float;
   }
 
-  public void setFloat(Float _float) {
+  public void setFloat(Optional<Float> _float) {
     this._float = _float;
   }
 
   public FormatTest _double(Double _double) {
-    this._double = _double;
+    this._double = Optional.of(_double);
     return this;
   }
 
@@ -193,19 +193,19 @@ public class FormatTest {
    * maximum: 123.4
    * @return _double
   */
-  @DecimalMin("67.8") @DecimalMax("123.4") 
+  
   @ApiModelProperty(value = "")
   @JsonProperty("double")
-  public Double getDouble() {
+  public Optional<@DecimalMin("67.8") @DecimalMax("123.4") Double> getDouble() {
     return _double;
   }
 
-  public void setDouble(Double _double) {
+  public void setDouble(Optional<Double> _double) {
     this._double = _double;
   }
 
   public FormatTest string(String string) {
-    this.string = string;
+    this.string = Optional.of(string);
     return this;
   }
 
@@ -213,14 +213,14 @@ public class FormatTest {
    * Get string
    * @return string
   */
-  @Pattern(regexp = "/[a-z]/i") 
+  
   @ApiModelProperty(value = "")
   @JsonProperty("string")
-  public String getString() {
+  public Optional<@Pattern(regexp = "/[a-z]/i") String> getString() {
     return string;
   }
 
-  public void setString(String string) {
+  public void setString(Optional<String> string) {
     this.string = string;
   }
 
@@ -245,7 +245,7 @@ public class FormatTest {
   }
 
   public FormatTest binary(org.springframework.core.io.Resource binary) {
-    this.binary = binary;
+    this.binary = Optional.of(binary);
     return this;
   }
 
@@ -256,11 +256,11 @@ public class FormatTest {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("binary")
-  public org.springframework.core.io.Resource getBinary() {
+  public Optional<org.springframework.core.io.Resource> getBinary() {
     return binary;
   }
 
-  public void setBinary(org.springframework.core.io.Resource binary) {
+  public void setBinary(Optional<org.springframework.core.io.Resource> binary) {
     this.binary = binary;
   }
 
@@ -285,7 +285,7 @@ public class FormatTest {
   }
 
   public FormatTest dateTime(OffsetDateTime dateTime) {
-    this.dateTime = dateTime;
+    this.dateTime = Optional.of(dateTime);
     return this;
   }
 
@@ -296,16 +296,16 @@ public class FormatTest {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("dateTime")
-  public OffsetDateTime getDateTime() {
+  public Optional<OffsetDateTime> getDateTime() {
     return dateTime;
   }
 
-  public void setDateTime(OffsetDateTime dateTime) {
+  public void setDateTime(Optional<OffsetDateTime> dateTime) {
     this.dateTime = dateTime;
   }
 
   public FormatTest uuid(UUID uuid) {
-    this.uuid = uuid;
+    this.uuid = Optional.of(uuid);
     return this;
   }
 
@@ -316,11 +316,11 @@ public class FormatTest {
   @Valid 
   @ApiModelProperty(example = "72f98069-206d-4f12-9f12-3d1e525a8e84", value = "")
   @JsonProperty("uuid")
-  public UUID getUuid() {
+  public Optional<UUID> getUuid() {
     return uuid;
   }
 
-  public void setUuid(UUID uuid) {
+  public void setUuid(Optional<UUID> uuid) {
     this.uuid = uuid;
   }
 
@@ -345,7 +345,7 @@ public class FormatTest {
   }
 
   public FormatTest bigDecimal(BigDecimal bigDecimal) {
-    this.bigDecimal = bigDecimal;
+    this.bigDecimal = Optional.of(bigDecimal);
     return this;
   }
 
@@ -356,11 +356,11 @@ public class FormatTest {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("BigDecimal")
-  public BigDecimal getBigDecimal() {
+  public Optional<BigDecimal> getBigDecimal() {
     return bigDecimal;
   }
 
-  public void setBigDecimal(BigDecimal bigDecimal) {
+  public void setBigDecimal(Optional<BigDecimal> bigDecimal) {
     this.bigDecimal = bigDecimal;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/HasOnlyReadOnly.java

@@ -24,12 +24,12 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class HasOnlyReadOnly {
 
-  private String bar;
+  private Optional<String> bar = Optional.empty();
 
-  private String foo;
+  private Optional<String> foo = Optional.empty();
 
   public HasOnlyReadOnly bar(String bar) {
-    this.bar = bar;
+    this.bar = Optional.of(bar);
     return this;
   }
 
@@ -40,16 +40,16 @@ public class HasOnlyReadOnly {
   
   @ApiModelProperty(readOnly = true, value = "")
   @JsonProperty("bar")
-  public String getBar() {
+  public Optional<String> getBar() {
     return bar;
   }
 
-  public void setBar(String bar) {
+  public void setBar(Optional<String> bar) {
     this.bar = bar;
   }
 
   public HasOnlyReadOnly foo(String foo) {
-    this.foo = foo;
+    this.foo = Optional.of(foo);
     return this;
   }
 
@@ -60,11 +60,11 @@ public class HasOnlyReadOnly {
   
   @ApiModelProperty(readOnly = true, value = "")
   @JsonProperty("foo")
-  public String getFoo() {
+  public Optional<String> getFoo() {
     return foo;
   }
 
-  public void setFoo(String foo) {
+  public void setFoo(Optional<String> foo) {
     this.foo = foo;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/MixedPropertiesAndAdditionalPropertiesClass.java

@@ -28,16 +28,16 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class MixedPropertiesAndAdditionalPropertiesClass {
 
-  private UUID uuid;
+  private Optional<UUID> uuid = Optional.empty();
 
   @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
-  private OffsetDateTime dateTime;
+  private Optional<OffsetDateTime> dateTime = Optional.empty();
 
   @Valid
   private Map<String, Animal> map = new HashMap<>();
 
   public MixedPropertiesAndAdditionalPropertiesClass uuid(UUID uuid) {
-    this.uuid = uuid;
+    this.uuid = Optional.of(uuid);
     return this;
   }
 
@@ -48,16 +48,16 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("uuid")
-  public UUID getUuid() {
+  public Optional<UUID> getUuid() {
     return uuid;
   }
 
-  public void setUuid(UUID uuid) {
+  public void setUuid(Optional<UUID> uuid) {
     this.uuid = uuid;
   }
 
   public MixedPropertiesAndAdditionalPropertiesClass dateTime(OffsetDateTime dateTime) {
-    this.dateTime = dateTime;
+    this.dateTime = Optional.of(dateTime);
     return this;
   }
 
@@ -68,11 +68,11 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("dateTime")
-  public OffsetDateTime getDateTime() {
+  public Optional<OffsetDateTime> getDateTime() {
     return dateTime;
   }
 
-  public void setDateTime(OffsetDateTime dateTime) {
+  public void setDateTime(Optional<OffsetDateTime> dateTime) {
     this.dateTime = dateTime;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Model200Response.java

@@ -25,12 +25,12 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Model200Response {
 
-  private Integer name;
+  private Optional<Integer> name = Optional.empty();
 
-  private String propertyClass;
+  private Optional<String> propertyClass = Optional.empty();
 
   public Model200Response name(Integer name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -41,16 +41,16 @@ public class Model200Response {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public Integer getName() {
+  public Optional<Integer> getName() {
     return name;
   }
 
-  public void setName(Integer name) {
+  public void setName(Optional<Integer> name) {
     this.name = name;
   }
 
   public Model200Response propertyClass(String propertyClass) {
-    this.propertyClass = propertyClass;
+    this.propertyClass = Optional.of(propertyClass);
     return this;
   }
 
@@ -61,11 +61,11 @@ public class Model200Response {
   
   @ApiModelProperty(value = "")
   @JsonProperty("class")
-  public String getPropertyClass() {
+  public Optional<String> getPropertyClass() {
     return propertyClass;
   }
 
-  public void setPropertyClass(String propertyClass) {
+  public void setPropertyClass(Optional<String> propertyClass) {
     this.propertyClass = propertyClass;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelApiResponse.java

@@ -24,14 +24,14 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class ModelApiResponse {
 
-  private Integer code;
+  private Optional<Integer> code = Optional.empty();
 
-  private String type;
+  private Optional<String> type = Optional.empty();
 
-  private String message;
+  private Optional<String> message = Optional.empty();
 
   public ModelApiResponse code(Integer code) {
-    this.code = code;
+    this.code = Optional.of(code);
     return this;
   }
 
@@ -42,16 +42,16 @@ public class ModelApiResponse {
   
   @ApiModelProperty(value = "")
   @JsonProperty("code")
-  public Integer getCode() {
+  public Optional<Integer> getCode() {
     return code;
   }
 
-  public void setCode(Integer code) {
+  public void setCode(Optional<Integer> code) {
     this.code = code;
   }
 
   public ModelApiResponse type(String type) {
-    this.type = type;
+    this.type = Optional.of(type);
     return this;
   }
 
@@ -62,16 +62,16 @@ public class ModelApiResponse {
   
   @ApiModelProperty(value = "")
   @JsonProperty("type")
-  public String getType() {
+  public Optional<String> getType() {
     return type;
   }
 
-  public void setType(String type) {
+  public void setType(Optional<String> type) {
     this.type = type;
   }
 
   public ModelApiResponse message(String message) {
-    this.message = message;
+    this.message = Optional.of(message);
     return this;
   }
 
@@ -82,11 +82,11 @@ public class ModelApiResponse {
   
   @ApiModelProperty(value = "")
   @JsonProperty("message")
-  public String getMessage() {
+  public Optional<String> getMessage() {
     return message;
   }
 
-  public void setMessage(String message) {
+  public void setMessage(Optional<String> message) {
     this.message = message;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelList.java

@@ -24,10 +24,10 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class ModelList {
 
-  private String _123list;
+  private Optional<String> _123list = Optional.empty();
 
   public ModelList _123list(String _123list) {
-    this._123list = _123list;
+    this._123list = Optional.of(_123list);
     return this;
   }
 
@@ -38,11 +38,11 @@ public class ModelList {
   
   @ApiModelProperty(value = "")
   @JsonProperty("123-list")
-  public String get123list() {
+  public Optional<String> get123list() {
     return _123list;
   }
 
-  public void set123list(String _123list) {
+  public void set123list(Optional<String> _123list) {
     this._123list = _123list;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ModelReturn.java

@@ -25,10 +25,10 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class ModelReturn {
 
-  private Integer _return;
+  private Optional<Integer> _return = Optional.empty();
 
   public ModelReturn _return(Integer _return) {
-    this._return = _return;
+    this._return = Optional.of(_return);
     return this;
   }
 
@@ -39,11 +39,11 @@ public class ModelReturn {
   
   @ApiModelProperty(value = "")
   @JsonProperty("return")
-  public Integer getReturn() {
+  public Optional<Integer> getReturn() {
     return _return;
   }
 
-  public void setReturn(Integer _return) {
+  public void setReturn(Optional<Integer> _return) {
     this._return = _return;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Name.java

@@ -25,11 +25,11 @@ public class Name {
 
   private Integer name;
 
-  private Integer snakeCase;
+  private Optional<Integer> snakeCase = Optional.empty();
 
-  private String property;
+  private Optional<String> property = Optional.empty();
 
-  private Integer _123number;
+  private Optional<Integer> _123number = Optional.empty();
 
   public Name() {
     super();
@@ -63,7 +63,7 @@ public class Name {
   }
 
   public Name snakeCase(Integer snakeCase) {
-    this.snakeCase = snakeCase;
+    this.snakeCase = Optional.of(snakeCase);
     return this;
   }
 
@@ -74,16 +74,16 @@ public class Name {
   
   @ApiModelProperty(readOnly = true, value = "")
   @JsonProperty("snake_case")
-  public Integer getSnakeCase() {
+  public Optional<Integer> getSnakeCase() {
     return snakeCase;
   }
 
-  public void setSnakeCase(Integer snakeCase) {
+  public void setSnakeCase(Optional<Integer> snakeCase) {
     this.snakeCase = snakeCase;
   }
 
   public Name property(String property) {
-    this.property = property;
+    this.property = Optional.of(property);
     return this;
   }
 
@@ -94,16 +94,16 @@ public class Name {
   
   @ApiModelProperty(value = "")
   @JsonProperty("property")
-  public String getProperty() {
+  public Optional<String> getProperty() {
     return property;
   }
 
-  public void setProperty(String property) {
+  public void setProperty(Optional<String> property) {
     this.property = property;
   }
 
   public Name _123number(Integer _123number) {
-    this._123number = _123number;
+    this._123number = Optional.of(_123number);
     return this;
   }
 
@@ -114,11 +114,11 @@ public class Name {
   
   @ApiModelProperty(readOnly = true, value = "")
   @JsonProperty("123Number")
-  public Integer get123number() {
+  public Optional<Integer> get123number() {
     return _123number;
   }
 
-  public void set123number(Integer _123number) {
+  public void set123number(Optional<Integer> _123number) {
     this._123number = _123number;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/NumberOnly.java

@@ -23,10 +23,10 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class NumberOnly {
 
-  private BigDecimal justNumber;
+  private Optional<BigDecimal> justNumber = Optional.empty();
 
   public NumberOnly justNumber(BigDecimal justNumber) {
-    this.justNumber = justNumber;
+    this.justNumber = Optional.of(justNumber);
     return this;
   }
 
@@ -37,11 +37,11 @@ public class NumberOnly {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("JustNumber")
-  public BigDecimal getJustNumber() {
+  public Optional<BigDecimal> getJustNumber() {
     return justNumber;
   }
 
-  public void setJustNumber(BigDecimal justNumber) {
+  public void setJustNumber(Optional<BigDecimal> justNumber) {
     this.justNumber = justNumber;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Order.java

@@ -25,14 +25,14 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Order {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private Long petId;
+  private Optional<Long> petId = Optional.empty();
 
-  private Integer quantity;
+  private Optional<Integer> quantity = Optional.empty();
 
   @DateTimeFormat(iso = DateTimeFormat.ISO.DATE_TIME)
-  private OffsetDateTime shipDate;
+  private Optional<OffsetDateTime> shipDate = Optional.empty();
 
   /**
    * Order Status
@@ -71,12 +71,12 @@ public class Order {
     }
   }
 
-  private StatusEnum status;
+  private Optional<StatusEnum> status = Optional.empty();
 
-  private Boolean complete = false;
+  private Optional<Boolean> complete = Optional.of(false);
 
   public Order id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -87,16 +87,16 @@ public class Order {
   
   @ApiModelProperty(value = "")
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public Order petId(Long petId) {
-    this.petId = petId;
+    this.petId = Optional.of(petId);
     return this;
   }
 
@@ -107,16 +107,16 @@ public class Order {
   
   @ApiModelProperty(value = "")
   @JsonProperty("petId")
-  public Long getPetId() {
+  public Optional<Long> getPetId() {
     return petId;
   }
 
-  public void setPetId(Long petId) {
+  public void setPetId(Optional<Long> petId) {
     this.petId = petId;
   }
 
   public Order quantity(Integer quantity) {
-    this.quantity = quantity;
+    this.quantity = Optional.of(quantity);
     return this;
   }
 
@@ -127,16 +127,16 @@ public class Order {
   
   @ApiModelProperty(value = "")
   @JsonProperty("quantity")
-  public Integer getQuantity() {
+  public Optional<Integer> getQuantity() {
     return quantity;
   }
 
-  public void setQuantity(Integer quantity) {
+  public void setQuantity(Optional<Integer> quantity) {
     this.quantity = quantity;
   }
 
   public Order shipDate(OffsetDateTime shipDate) {
-    this.shipDate = shipDate;
+    this.shipDate = Optional.of(shipDate);
     return this;
   }
 
@@ -147,16 +147,16 @@ public class Order {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("shipDate")
-  public OffsetDateTime getShipDate() {
+  public Optional<OffsetDateTime> getShipDate() {
     return shipDate;
   }
 
-  public void setShipDate(OffsetDateTime shipDate) {
+  public void setShipDate(Optional<OffsetDateTime> shipDate) {
     this.shipDate = shipDate;
   }
 
   public Order status(StatusEnum status) {
-    this.status = status;
+    this.status = Optional.of(status);
     return this;
   }
 
@@ -167,16 +167,16 @@ public class Order {
   
   @ApiModelProperty(value = "Order Status")
   @JsonProperty("status")
-  public StatusEnum getStatus() {
+  public Optional<StatusEnum> getStatus() {
     return status;
   }
 
-  public void setStatus(StatusEnum status) {
+  public void setStatus(Optional<StatusEnum> status) {
     this.status = status;
   }
 
   public Order complete(Boolean complete) {
-    this.complete = complete;
+    this.complete = Optional.of(complete);
     return this;
   }
 
@@ -187,11 +187,11 @@ public class Order {
   
   @ApiModelProperty(value = "")
   @JsonProperty("complete")
-  public Boolean getComplete() {
+  public Optional<Boolean> getComplete() {
     return complete;
   }
 
-  public void setComplete(Boolean complete) {
+  public void setComplete(Optional<Boolean> complete) {
     this.complete = complete;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/OuterComposite.java

@@ -23,14 +23,14 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class OuterComposite {
 
-  private BigDecimal myNumber;
+  private Optional<BigDecimal> myNumber = Optional.empty();
 
-  private String myString;
+  private Optional<String> myString = Optional.empty();
 
-  private Boolean myBoolean;
+  private Optional<Boolean> myBoolean = Optional.empty();
 
   public OuterComposite myNumber(BigDecimal myNumber) {
-    this.myNumber = myNumber;
+    this.myNumber = Optional.of(myNumber);
     return this;
   }
 
@@ -41,16 +41,16 @@ public class OuterComposite {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("my_number")
-  public BigDecimal getMyNumber() {
+  public Optional<BigDecimal> getMyNumber() {
     return myNumber;
   }
 
-  public void setMyNumber(BigDecimal myNumber) {
+  public void setMyNumber(Optional<BigDecimal> myNumber) {
     this.myNumber = myNumber;
   }
 
   public OuterComposite myString(String myString) {
-    this.myString = myString;
+    this.myString = Optional.of(myString);
     return this;
   }
 
@@ -61,16 +61,16 @@ public class OuterComposite {
   
   @ApiModelProperty(value = "")
   @JsonProperty("my_string")
-  public String getMyString() {
+  public Optional<String> getMyString() {
     return myString;
   }
 
-  public void setMyString(String myString) {
+  public void setMyString(Optional<String> myString) {
     this.myString = myString;
   }
 
   public OuterComposite myBoolean(Boolean myBoolean) {
-    this.myBoolean = myBoolean;
+    this.myBoolean = Optional.of(myBoolean);
     return this;
   }
 
@@ -81,11 +81,11 @@ public class OuterComposite {
   
   @ApiModelProperty(value = "")
   @JsonProperty("my_boolean")
-  public Boolean getMyBoolean() {
+  public Optional<Boolean> getMyBoolean() {
     return myBoolean;
   }
 
-  public void setMyBoolean(Boolean myBoolean) {
+  public void setMyBoolean(Optional<Boolean> myBoolean) {
     this.myBoolean = myBoolean;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ParentWithNullable.java

@@ -71,12 +71,12 @@ public class ParentWithNullable {
     }
   }
 
-  private TypeEnum type;
+  private Optional<TypeEnum> type = Optional.empty();
 
   private JsonNullable<String> nullableProperty = JsonNullable.<String>undefined();
 
   public ParentWithNullable type(TypeEnum type) {
-    this.type = type;
+    this.type = Optional.of(type);
     return this;
   }
 
@@ -87,11 +87,11 @@ public class ParentWithNullable {
   
   @ApiModelProperty(value = "")
   @JsonProperty("type")
-  public TypeEnum getType() {
+  public Optional<TypeEnum> getType() {
     return type;
   }
 
-  public void setType(TypeEnum type) {
+  public void setType(Optional<TypeEnum> type) {
     this.type = type;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Pet.java

@@ -31,9 +31,9 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Pet {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private Category category;
+  private Optional<Category> category = Optional.empty();
 
   private String name;
 
@@ -81,7 +81,7 @@ public class Pet {
   }
 
   @Deprecated
-  private StatusEnum status;
+  private Optional<StatusEnum> status = Optional.empty();
 
   public Pet() {
     super();
@@ -96,7 +96,7 @@ public class Pet {
   }
 
   public Pet id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -107,16 +107,16 @@ public class Pet {
   
   @ApiModelProperty(value = "")
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public Pet category(Category category) {
-    this.category = category;
+    this.category = Optional.of(category);
     return this;
   }
 
@@ -127,11 +127,11 @@ public class Pet {
   @Valid 
   @ApiModelProperty(value = "")
   @JsonProperty("category")
-  public Category getCategory() {
+  public Optional<Category> getCategory() {
     return category;
   }
 
-  public void setCategory(Category category) {
+  public void setCategory(Optional<Category> category) {
     this.category = category;
   }
 
@@ -213,7 +213,7 @@ public class Pet {
   }
 
   public Pet status(StatusEnum status) {
-    this.status = status;
+    this.status = Optional.of(status);
     return this;
   }
 
@@ -226,7 +226,7 @@ public class Pet {
   @ApiModelProperty(value = "pet status in the store")
   @JsonProperty("status")
   @Deprecated
-  public StatusEnum getStatus() {
+  public Optional<StatusEnum> getStatus() {
     return status;
   }
 
@@ -234,7 +234,7 @@ public class Pet {
    * @deprecated
   */
   @Deprecated
-  public void setStatus(StatusEnum status) {
+  public void setStatus(Optional<StatusEnum> status) {
     this.status = status;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ReadOnlyFirst.java

@@ -22,12 +22,12 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class ReadOnlyFirst {
 
-  private String bar;
+  private Optional<String> bar = Optional.empty();
 
-  private String baz;
+  private Optional<String> baz = Optional.empty();
 
   public ReadOnlyFirst bar(String bar) {
-    this.bar = bar;
+    this.bar = Optional.of(bar);
     return this;
   }
 
@@ -38,16 +38,16 @@ public class ReadOnlyFirst {
   
   @ApiModelProperty(readOnly = true, value = "")
   @JsonProperty("bar")
-  public String getBar() {
+  public Optional<String> getBar() {
     return bar;
   }
 
-  public void setBar(String bar) {
+  public void setBar(Optional<String> bar) {
     this.bar = bar;
   }
 
   public ReadOnlyFirst baz(String baz) {
-    this.baz = baz;
+    this.baz = Optional.of(baz);
     return this;
   }
 
@@ -58,11 +58,11 @@ public class ReadOnlyFirst {
   
   @ApiModelProperty(value = "")
   @JsonProperty("baz")
-  public String getBaz() {
+  public Optional<String> getBaz() {
     return baz;
   }
 
-  public void setBaz(String baz) {
+  public void setBaz(Optional<String> baz) {
     this.baz = baz;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/ResponseObjectWithDifferentFieldNames.java

@@ -22,16 +22,16 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class ResponseObjectWithDifferentFieldNames {
 
-  private String normalPropertyName;
+  private Optional<String> normalPropertyName = Optional.empty();
 
-  private String UPPER_CASE_PROPERTY_SNAKE;
+  private Optional<String> UPPER_CASE_PROPERTY_SNAKE = Optional.empty();
 
-  private String lowerCasePropertyDashes;
+  private Optional<String> lowerCasePropertyDashes = Optional.empty();
 
-  private String propertyNameWithSpaces;
+  private Optional<String> propertyNameWithSpaces = Optional.empty();
 
   public ResponseObjectWithDifferentFieldNames normalPropertyName(String normalPropertyName) {
-    this.normalPropertyName = normalPropertyName;
+    this.normalPropertyName = Optional.of(normalPropertyName);
     return this;
   }
 
@@ -42,16 +42,16 @@ public class ResponseObjectWithDifferentFieldNames {
   
   @ApiModelProperty(value = "")
   @JsonProperty("normalPropertyName")
-  public String getNormalPropertyName() {
+  public Optional<String> getNormalPropertyName() {
     return normalPropertyName;
   }
 
-  public void setNormalPropertyName(String normalPropertyName) {
+  public void setNormalPropertyName(Optional<String> normalPropertyName) {
     this.normalPropertyName = normalPropertyName;
   }
 
   public ResponseObjectWithDifferentFieldNames UPPER_CASE_PROPERTY_SNAKE(String UPPER_CASE_PROPERTY_SNAKE) {
-    this.UPPER_CASE_PROPERTY_SNAKE = UPPER_CASE_PROPERTY_SNAKE;
+    this.UPPER_CASE_PROPERTY_SNAKE = Optional.of(UPPER_CASE_PROPERTY_SNAKE);
     return this;
   }
 
@@ -62,16 +62,16 @@ public class ResponseObjectWithDifferentFieldNames {
   
   @ApiModelProperty(value = "")
   @JsonProperty("UPPER_CASE_PROPERTY_SNAKE")
-  public String getUPPERCASEPROPERTYSNAKE() {
+  public Optional<String> getUPPERCASEPROPERTYSNAKE() {
     return UPPER_CASE_PROPERTY_SNAKE;
   }
 
-  public void setUPPERCASEPROPERTYSNAKE(String UPPER_CASE_PROPERTY_SNAKE) {
+  public void setUPPERCASEPROPERTYSNAKE(Optional<String> UPPER_CASE_PROPERTY_SNAKE) {
     this.UPPER_CASE_PROPERTY_SNAKE = UPPER_CASE_PROPERTY_SNAKE;
   }
 
   public ResponseObjectWithDifferentFieldNames lowerCasePropertyDashes(String lowerCasePropertyDashes) {
-    this.lowerCasePropertyDashes = lowerCasePropertyDashes;
+    this.lowerCasePropertyDashes = Optional.of(lowerCasePropertyDashes);
     return this;
   }
 
@@ -82,16 +82,16 @@ public class ResponseObjectWithDifferentFieldNames {
   
   @ApiModelProperty(value = "")
   @JsonProperty("lower-case-property-dashes")
-  public String getLowerCasePropertyDashes() {
+  public Optional<String> getLowerCasePropertyDashes() {
     return lowerCasePropertyDashes;
   }
 
-  public void setLowerCasePropertyDashes(String lowerCasePropertyDashes) {
+  public void setLowerCasePropertyDashes(Optional<String> lowerCasePropertyDashes) {
     this.lowerCasePropertyDashes = lowerCasePropertyDashes;
   }
 
   public ResponseObjectWithDifferentFieldNames propertyNameWithSpaces(String propertyNameWithSpaces) {
-    this.propertyNameWithSpaces = propertyNameWithSpaces;
+    this.propertyNameWithSpaces = Optional.of(propertyNameWithSpaces);
     return this;
   }
 
@@ -102,11 +102,11 @@ public class ResponseObjectWithDifferentFieldNames {
   
   @ApiModelProperty(value = "")
   @JsonProperty("property name with spaces")
-  public String getPropertyNameWithSpaces() {
+  public Optional<String> getPropertyNameWithSpaces() {
     return propertyNameWithSpaces;
   }
 
-  public void setPropertyNameWithSpaces(String propertyNameWithSpaces) {
+  public void setPropertyNameWithSpaces(Optional<String> propertyNameWithSpaces) {
     this.propertyNameWithSpaces = propertyNameWithSpaces;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/SpecialModelName.java

@@ -24,10 +24,10 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class SpecialModelName {
 
-  private Long $specialPropertyName;
+  private Optional<Long> $specialPropertyName = Optional.empty();
 
   public SpecialModelName $specialPropertyName(Long $specialPropertyName) {
-    this.$specialPropertyName = $specialPropertyName;
+    this.$specialPropertyName = Optional.of($specialPropertyName);
     return this;
   }
 
@@ -38,11 +38,11 @@ public class SpecialModelName {
   
   @ApiModelProperty(value = "")
   @JsonProperty("$special[property.name]")
-  public Long get$SpecialPropertyName() {
+  public Optional<Long> get$SpecialPropertyName() {
     return $specialPropertyName;
   }
 
-  public void set$SpecialPropertyName(Long $specialPropertyName) {
+  public void set$SpecialPropertyName(Optional<Long> $specialPropertyName) {
     this.$specialPropertyName = $specialPropertyName;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/Tag.java

@@ -22,12 +22,12 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class Tag {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private String name;
+  private Optional<String> name = Optional.empty();
 
   public Tag id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -38,16 +38,16 @@ public class Tag {
   
   @ApiModelProperty(value = "")
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public Tag name(String name) {
-    this.name = name;
+    this.name = Optional.of(name);
     return this;
   }
 
@@ -58,11 +58,11 @@ public class Tag {
   
   @ApiModelProperty(value = "")
   @JsonProperty("name")
-  public String getName() {
+  public Optional<String> getName() {
     return name;
   }
 
-  public void setName(String name) {
+  public void setName(Optional<String> name) {
     this.name = name;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/User.java

@@ -22,24 +22,24 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class User {
 
-  private Long id;
+  private Optional<Long> id = Optional.empty();
 
-  private String username;
+  private Optional<String> username = Optional.empty();
 
-  private String firstName;
+  private Optional<String> firstName = Optional.empty();
 
-  private String lastName;
+  private Optional<String> lastName = Optional.empty();
 
-  private String email;
+  private Optional<String> email = Optional.empty();
 
-  private String password;
+  private Optional<String> password = Optional.empty();
 
-  private String phone;
+  private Optional<String> phone = Optional.empty();
 
-  private Integer userStatus;
+  private Optional<Integer> userStatus = Optional.empty();
 
   public User id(Long id) {
-    this.id = id;
+    this.id = Optional.of(id);
     return this;
   }
 
@@ -50,16 +50,16 @@ public class User {
   
   @ApiModelProperty(value = "")
   @JsonProperty("id")
-  public Long getId() {
+  public Optional<Long> getId() {
     return id;
   }
 
-  public void setId(Long id) {
+  public void setId(Optional<Long> id) {
     this.id = id;
   }
 
   public User username(String username) {
-    this.username = username;
+    this.username = Optional.of(username);
     return this;
   }
 
@@ -70,16 +70,16 @@ public class User {
   
   @ApiModelProperty(value = "")
   @JsonProperty("username")
-  public String getUsername() {
+  public Optional<String> getUsername() {
     return username;
   }
 
-  public void setUsername(String username) {
+  public void setUsername(Optional<String> username) {
     this.username = username;
   }
 
   public User firstName(String firstName) {
-    this.firstName = firstName;
+    this.firstName = Optional.of(firstName);
     return this;
   }
 
@@ -90,16 +90,16 @@ public class User {
   
   @ApiModelProperty(value = "")
   @JsonProperty("firstName")
-  public String getFirstName() {
+  public Optional<String> getFirstName() {
     return firstName;
   }
 
-  public void setFirstName(String firstName) {
+  public void setFirstName(Optional<String> firstName) {
     this.firstName = firstName;
   }
 
   public User lastName(String lastName) {
-    this.lastName = lastName;
+    this.lastName = Optional.of(lastName);
     return this;
   }
 
@@ -110,16 +110,16 @@ public class User {
   
   @ApiModelProperty(value = "")
   @JsonProperty("lastName")
-  public String getLastName() {
+  public Optional<String> getLastName() {
     return lastName;
   }
 
-  public void setLastName(String lastName) {
+  public void setLastName(Optional<String> lastName) {
     this.lastName = lastName;
   }
 
   public User email(String email) {
-    this.email = email;
+    this.email = Optional.of(email);
     return this;
   }
 
@@ -130,16 +130,16 @@ public class User {
   
   @ApiModelProperty(value = "")
   @JsonProperty("email")
-  public String getEmail() {
+  public Optional<String> getEmail() {
     return email;
   }
 
-  public void setEmail(String email) {
+  public void setEmail(Optional<String> email) {
     this.email = email;
   }
 
   public User password(String password) {
-    this.password = password;
+    this.password = Optional.of(password);
     return this;
   }
 
@@ -150,16 +150,16 @@ public class User {
   
   @ApiModelProperty(value = "")
   @JsonProperty("password")
-  public String getPassword() {
+  public Optional<String> getPassword() {
     return password;
   }
 
-  public void setPassword(String password) {
+  public void setPassword(Optional<String> password) {
     this.password = password;
   }
 
   public User phone(String phone) {
-    this.phone = phone;
+    this.phone = Optional.of(phone);
     return this;
   }
 
@@ -170,16 +170,16 @@ public class User {
   
   @ApiModelProperty(value = "")
   @JsonProperty("phone")
-  public String getPhone() {
+  public Optional<String> getPhone() {
     return phone;
   }
 
-  public void setPhone(String phone) {
+  public void setPhone(Optional<String> phone) {
     this.phone = phone;
   }
 
   public User userStatus(Integer userStatus) {
-    this.userStatus = userStatus;
+    this.userStatus = Optional.of(userStatus);
     return this;
   }
 
@@ -190,11 +190,11 @@ public class User {
   
   @ApiModelProperty(value = "User Status")
   @JsonProperty("userStatus")
-  public Integer getUserStatus() {
+  public Optional<Integer> getUserStatus() {
     return userStatus;
   }
 
-  public void setUserStatus(Integer userStatus) {
+  public void setUserStatus(Optional<Integer> userStatus) {
     this.userStatus = userStatus;
   }
 

samples/server/petstore/springboot-useoptional/src/main/java/org/openapitools/model/XmlItem.java

@@ -26,24 +26,24 @@ import javax.annotation.Generated;
 @Generated(value = "org.openapitools.codegen.languages.SpringCodegen")
 public class XmlItem {
 
-  private String attributeString;
+  private Optional<String> attributeString = Optional.empty();
 
-  private BigDecimal attributeNumber;
+  private Optional<BigDecimal> attributeNumber = Optional.empty();
 
-  private Integer attributeInteger;
+  private Optional<Integer> attributeInteger = Optional.empty();
 
-  private Boolean attributeBoolean;
+  private Optional<Boolean> attributeBoolean = Optional.empty();
 
   @Valid
   private List<Integer> wrappedArray;
 
-  private String nameString;
+  private Optional<String> nameString = Optional.empty();
 
-  private BigDecimal nameNumber;
+  private Optional<BigDecimal> nameNumber = Optional.empty();
 
-  private Integer nameInteger;
+  private Optional<Integer> nameInteger = Optional.empty();
 
-  private Boolean nameBoolean;
+  private Optional<Boolean> nameBoolean = Optional.empty();
 
   @Valid
   private List<Integer> nameArray;
@@ -51,13 +51,13 @@ public class XmlItem {
   @Valid
   private List<Integer> nameWrappedArray;
 
-  private String prefixString;
+  private Optional<String> prefixString = Optional.empty();
 
-  private BigDecimal prefixNumber;
+  private Optional<BigDecimal> prefixNumber = Optional.empty();
 
-  private Integer prefixInteger;
+  private Optional<Integer> prefixInteger = Optional.empty();
 
-  private Boolean prefixBoolean;
+  private Optional<Boolean> prefixBoolean = Optional.empty();
 
   @Valid
   private List<Integer> prefixArray;
@@ -65,13 +65,13 @@ public class XmlItem {
   @Valid
   private List<Integer> prefixWrappedArray;
 
-  private String namespaceString;
+  private Optional<String> namespaceString = Optional.empty();
 
-  private BigDecimal namespaceNumber;
+  private Optional<BigDecimal> namespaceNumber = Optional.empty();
 
-  private Integer namespaceInteger;
+  private Optional<Integer> namespaceInteger = Optional.empty();
 
-  private Boolean namespaceBoolean;
+  private Optional<Boolean> namespaceBoolean = Optional.empty();
 
   @Valid
   private List<Integer> namespaceArray;
@@ -79,13 +79,13 @@ public class XmlItem {
   @Valid
   private List<Integer> namespaceWrappedArray;
 
-  private String prefixNsString;
+  private Optional<String> prefixNsString = Optional.empty();
 
-  private BigDecimal prefixNsNumber;
+  private Optional<BigDecimal> prefixNsNumber = Optional.empty();
 
-  private Integer prefixNsInteger;
+  private Optional<Integer> prefixNsInteger = Optional.empty();
 
-  private Boolean prefixNsBoolean;
+  private Optional<Boolean> prefixNsBoolean = Optional.empty();
 
   @Valid
   private List<Integer> prefixNsArray;
@@ -94,7 +94,7 @@ public class XmlItem {
   private List<Integer> prefixNsWrappedArray;
 
   public XmlItem attributeString(String attributeString) {
-    this.attributeString = attributeString;
+    this.attributeString = Optional.of(attributeString);
     return this;
   }
 
@@ -105,16 +105,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "string", value = "")
   @JsonProperty("attribute_string")
-  public String getAttributeString() {
+  public Optional<String> getAttributeString() {
     return attributeString;
   }
 
-  public void setAttributeString(String attributeString) {
+  public void setAttributeString(Optional<String> attributeString) {
     this.attributeString = attributeString;
   }
 
   public XmlItem attributeNumber(BigDecimal attributeNumber) {
-    this.attributeNumber = attributeNumber;
+    this.attributeNumber = Optional.of(attributeNumber);
     return this;
   }
 
@@ -125,16 +125,16 @@ public class XmlItem {
   @Valid 
   @ApiModelProperty(example = "1.234", value = "")
   @JsonProperty("attribute_number")
-  public BigDecimal getAttributeNumber() {
+  public Optional<BigDecimal> getAttributeNumber() {
     return attributeNumber;
   }
 
-  public void setAttributeNumber(BigDecimal attributeNumber) {
+  public void setAttributeNumber(Optional<BigDecimal> attributeNumber) {
     this.attributeNumber = attributeNumber;
   }
 
   public XmlItem attributeInteger(Integer attributeInteger) {
-    this.attributeInteger = attributeInteger;
+    this.attributeInteger = Optional.of(attributeInteger);
     return this;
   }
 
@@ -145,16 +145,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "-2", value = "")
   @JsonProperty("attribute_integer")
-  public Integer getAttributeInteger() {
+  public Optional<Integer> getAttributeInteger() {
     return attributeInteger;
   }
 
-  public void setAttributeInteger(Integer attributeInteger) {
+  public void setAttributeInteger(Optional<Integer> attributeInteger) {
     this.attributeInteger = attributeInteger;
   }
 
   public XmlItem attributeBoolean(Boolean attributeBoolean) {
-    this.attributeBoolean = attributeBoolean;
+    this.attributeBoolean = Optional.of(attributeBoolean);
     return this;
   }
 
@@ -165,11 +165,11 @@ public class XmlItem {
   
   @ApiModelProperty(example = "true", value = "")
   @JsonProperty("attribute_boolean")
-  public Boolean getAttributeBoolean() {
+  public Optional<Boolean> getAttributeBoolean() {
     return attributeBoolean;
   }
 
-  public void setAttributeBoolean(Boolean attributeBoolean) {
+  public void setAttributeBoolean(Optional<Boolean> attributeBoolean) {
     this.attributeBoolean = attributeBoolean;
   }
 
@@ -202,7 +202,7 @@ public class XmlItem {
   }
 
   public XmlItem nameString(String nameString) {
-    this.nameString = nameString;
+    this.nameString = Optional.of(nameString);
     return this;
   }
 
@@ -213,16 +213,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "string", value = "")
   @JsonProperty("name_string")
-  public String getNameString() {
+  public Optional<String> getNameString() {
     return nameString;
   }
 
-  public void setNameString(String nameString) {
+  public void setNameString(Optional<String> nameString) {
     this.nameString = nameString;
   }
 
   public XmlItem nameNumber(BigDecimal nameNumber) {
-    this.nameNumber = nameNumber;
+    this.nameNumber = Optional.of(nameNumber);
     return this;
   }
 
@@ -233,16 +233,16 @@ public class XmlItem {
   @Valid 
   @ApiModelProperty(example = "1.234", value = "")
   @JsonProperty("name_number")
-  public BigDecimal getNameNumber() {
+  public Optional<BigDecimal> getNameNumber() {
     return nameNumber;
   }
 
-  public void setNameNumber(BigDecimal nameNumber) {
+  public void setNameNumber(Optional<BigDecimal> nameNumber) {
     this.nameNumber = nameNumber;
   }
 
   public XmlItem nameInteger(Integer nameInteger) {
-    this.nameInteger = nameInteger;
+    this.nameInteger = Optional.of(nameInteger);
     return this;
   }
 
@@ -253,16 +253,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "-2", value = "")
   @JsonProperty("name_integer")
-  public Integer getNameInteger() {
+  public Optional<Integer> getNameInteger() {
     return nameInteger;
   }
 
-  public void setNameInteger(Integer nameInteger) {
+  public void setNameInteger(Optional<Integer> nameInteger) {
     this.nameInteger = nameInteger;
   }
 
   public XmlItem nameBoolean(Boolean nameBoolean) {
-    this.nameBoolean = nameBoolean;
+    this.nameBoolean = Optional.of(nameBoolean);
     return this;
   }
 
@@ -273,11 +273,11 @@ public class XmlItem {
   
   @ApiModelProperty(example = "true", value = "")
   @JsonProperty("name_boolean")
-  public Boolean getNameBoolean() {
+  public Optional<Boolean> getNameBoolean() {
     return nameBoolean;
   }
 
-  public void setNameBoolean(Boolean nameBoolean) {
+  public void setNameBoolean(Optional<Boolean> nameBoolean) {
     this.nameBoolean = nameBoolean;
   }
 
@@ -338,7 +338,7 @@ public class XmlItem {
   }
 
   public XmlItem prefixString(String prefixString) {
-    this.prefixString = prefixString;
+    this.prefixString = Optional.of(prefixString);
     return this;
   }
 
@@ -349,16 +349,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "string", value = "")
   @JsonProperty("prefix_string")
-  public String getPrefixString() {
+  public Optional<String> getPrefixString() {
     return prefixString;
   }
 
-  public void setPrefixString(String prefixString) {
+  public void setPrefixString(Optional<String> prefixString) {
     this.prefixString = prefixString;
   }
 
   public XmlItem prefixNumber(BigDecimal prefixNumber) {
-    this.prefixNumber = prefixNumber;
+    this.prefixNumber = Optional.of(prefixNumber);
     return this;
   }
 
@@ -369,16 +369,16 @@ public class XmlItem {
   @Valid 
   @ApiModelProperty(example = "1.234", value = "")
   @JsonProperty("prefix_number")
-  public BigDecimal getPrefixNumber() {
+  public Optional<BigDecimal> getPrefixNumber() {
     return prefixNumber;
   }
 
-  public void setPrefixNumber(BigDecimal prefixNumber) {
+  public void setPrefixNumber(Optional<BigDecimal> prefixNumber) {
     this.prefixNumber = prefixNumber;
   }
 
   public XmlItem prefixInteger(Integer prefixInteger) {
-    this.prefixInteger = prefixInteger;
+    this.prefixInteger = Optional.of(prefixInteger);
     return this;
   }
 
@@ -389,16 +389,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "-2", value = "")
   @JsonProperty("prefix_integer")
-  public Integer getPrefixInteger() {
+  public Optional<Integer> getPrefixInteger() {
     return prefixInteger;
   }
 
-  public void setPrefixInteger(Integer prefixInteger) {
+  public void setPrefixInteger(Optional<Integer> prefixInteger) {
     this.prefixInteger = prefixInteger;
   }
 
   public XmlItem prefixBoolean(Boolean prefixBoolean) {
-    this.prefixBoolean = prefixBoolean;
+    this.prefixBoolean = Optional.of(prefixBoolean);
     return this;
   }
 
@@ -409,11 +409,11 @@ public class XmlItem {
   
   @ApiModelProperty(example = "true", value = "")
   @JsonProperty("prefix_boolean")
-  public Boolean getPrefixBoolean() {
+  public Optional<Boolean> getPrefixBoolean() {
     return prefixBoolean;
   }
 
-  public void setPrefixBoolean(Boolean prefixBoolean) {
+  public void setPrefixBoolean(Optional<Boolean> prefixBoolean) {
     this.prefixBoolean = prefixBoolean;
   }
 
@@ -474,7 +474,7 @@ public class XmlItem {
   }
 
   public XmlItem namespaceString(String namespaceString) {
-    this.namespaceString = namespaceString;
+    this.namespaceString = Optional.of(namespaceString);
     return this;
   }
 
@@ -485,16 +485,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "string", value = "")
   @JsonProperty("namespace_string")
-  public String getNamespaceString() {
+  public Optional<String> getNamespaceString() {
     return namespaceString;
   }
 
-  public void setNamespaceString(String namespaceString) {
+  public void setNamespaceString(Optional<String> namespaceString) {
     this.namespaceString = namespaceString;
   }
 
   public XmlItem namespaceNumber(BigDecimal namespaceNumber) {
-    this.namespaceNumber = namespaceNumber;
+    this.namespaceNumber = Optional.of(namespaceNumber);
     return this;
   }
 
@@ -505,16 +505,16 @@ public class XmlItem {
   @Valid 
   @ApiModelProperty(example = "1.234", value = "")
   @JsonProperty("namespace_number")
-  public BigDecimal getNamespaceNumber() {
+  public Optional<BigDecimal> getNamespaceNumber() {
     return namespaceNumber;
   }
 
-  public void setNamespaceNumber(BigDecimal namespaceNumber) {
+  public void setNamespaceNumber(Optional<BigDecimal> namespaceNumber) {
     this.namespaceNumber = namespaceNumber;
   }
 
   public XmlItem namespaceInteger(Integer namespaceInteger) {
-    this.namespaceInteger = namespaceInteger;
+    this.namespaceInteger = Optional.of(namespaceInteger);
     return this;
   }
 
@@ -525,16 +525,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "-2", value = "")
   @JsonProperty("namespace_integer")
-  public Integer getNamespaceInteger() {
+  public Optional<Integer> getNamespaceInteger() {
     return namespaceInteger;
   }
 
-  public void setNamespaceInteger(Integer namespaceInteger) {
+  public void setNamespaceInteger(Optional<Integer> namespaceInteger) {
     this.namespaceInteger = namespaceInteger;
   }
 
   public XmlItem namespaceBoolean(Boolean namespaceBoolean) {
-    this.namespaceBoolean = namespaceBoolean;
+    this.namespaceBoolean = Optional.of(namespaceBoolean);
     return this;
   }
 
@@ -545,11 +545,11 @@ public class XmlItem {
   
   @ApiModelProperty(example = "true", value = "")
   @JsonProperty("namespace_boolean")
-  public Boolean getNamespaceBoolean() {
+  public Optional<Boolean> getNamespaceBoolean() {
     return namespaceBoolean;
   }
 
-  public void setNamespaceBoolean(Boolean namespaceBoolean) {
+  public void setNamespaceBoolean(Optional<Boolean> namespaceBoolean) {
     this.namespaceBoolean = namespaceBoolean;
   }
 
@@ -610,7 +610,7 @@ public class XmlItem {
   }
 
   public XmlItem prefixNsString(String prefixNsString) {
-    this.prefixNsString = prefixNsString;
+    this.prefixNsString = Optional.of(prefixNsString);
     return this;
   }
 
@@ -621,16 +621,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "string", value = "")
   @JsonProperty("prefix_ns_string")
-  public String getPrefixNsString() {
+  public Optional<String> getPrefixNsString() {
     return prefixNsString;
   }
 
-  public void setPrefixNsString(String prefixNsString) {
+  public void setPrefixNsString(Optional<String> prefixNsString) {
     this.prefixNsString = prefixNsString;
   }
 
   public XmlItem prefixNsNumber(BigDecimal prefixNsNumber) {
-    this.prefixNsNumber = prefixNsNumber;
+    this.prefixNsNumber = Optional.of(prefixNsNumber);
     return this;
   }
 
@@ -641,16 +641,16 @@ public class XmlItem {
   @Valid 
   @ApiModelProperty(example = "1.234", value = "")
   @JsonProperty("prefix_ns_number")
-  public BigDecimal getPrefixNsNumber() {
+  public Optional<BigDecimal> getPrefixNsNumber() {
     return prefixNsNumber;
   }
 
-  public void setPrefixNsNumber(BigDecimal prefixNsNumber) {
+  public void setPrefixNsNumber(Optional<BigDecimal> prefixNsNumber) {
     this.prefixNsNumber = prefixNsNumber;
   }
 
   public XmlItem prefixNsInteger(Integer prefixNsInteger) {
-    this.prefixNsInteger = prefixNsInteger;
+    this.prefixNsInteger = Optional.of(prefixNsInteger);
     return this;
   }
 
@@ -661,16 +661,16 @@ public class XmlItem {
   
   @ApiModelProperty(example = "-2", value = "")
   @JsonProperty("prefix_ns_integer")
-  public Integer getPrefixNsInteger() {
+  public Optional<Integer> getPrefixNsInteger() {
     return prefixNsInteger;
   }
 
-  public void setPrefixNsInteger(Integer prefixNsInteger) {
+  public void setPrefixNsInteger(Optional<Integer> prefixNsInteger) {
     this.prefixNsInteger = prefixNsInteger;
   }
 
   public XmlItem prefixNsBoolean(Boolean prefixNsBoolean) {
-    this.prefixNsBoolean = prefixNsBoolean;
+    this.prefixNsBoolean = Optional.of(prefixNsBoolean);
     return this;
   }
 
@@ -681,11 +681,11 @@ public class XmlItem {
   
   @ApiModelProperty(example = "true", value = "")
   @JsonProperty("prefix_ns_boolean")
-  public Boolean getPrefixNsBoolean() {
+  public Optional<Boolean> getPrefixNsBoolean() {
     return prefixNsBoolean;
   }
 
-  public void setPrefixNsBoolean(Boolean prefixNsBoolean) {
+  public void setPrefixNsBoolean(Optional<Boolean> prefixNsBoolean) {
     this.prefixNsBoolean = prefixNsBoolean;
   }