diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/AdditionalPropertiesClass.java
index 7fe69e168fd..0c24badae38 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/AdditionalPropertiesClass.java
@@ -41,7 +41,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapPropertyItem(String key, String mapPropertyItem) {
     if (this.mapProperty == null) {
-      this.mapProperty = new HashMap<String, String>();
+      this.mapProperty = new HashMap<>();
     }
     this.mapProperty.put(key, mapPropertyItem);
     return this;
@@ -67,7 +67,7 @@ public class AdditionalPropertiesClass {
 
   public AdditionalPropertiesClass putMapOfMapPropertyItem(String key, Map<String, String> mapOfMapPropertyItem) {
     if (this.mapOfMapProperty == null) {
-      this.mapOfMapProperty = new HashMap<String, Map<String, String>>();
+      this.mapOfMapProperty = new HashMap<>();
     }
     this.mapOfMapProperty.put(key, mapOfMapPropertyItem);
     return this;
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayOfArrayOfNumberOnly.java
index b7e59a030a4..5997b31cbd4 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayOfArrayOfNumberOnly.java
@@ -38,7 +38,7 @@ public class ArrayOfArrayOfNumberOnly {
 
   public ArrayOfArrayOfNumberOnly addArrayArrayNumberItem(List<BigDecimal> arrayArrayNumberItem) {
     if (this.arrayArrayNumber == null) {
-      this.arrayArrayNumber = new ArrayList<List<BigDecimal>>();
+      this.arrayArrayNumber = new ArrayList<>();
     }
     this.arrayArrayNumber.add(arrayArrayNumberItem);
     return this;
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayOfNumberOnly.java
index fdfeb6856f3..2bc17f88eb3 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayOfNumberOnly.java
@@ -38,7 +38,7 @@ public class ArrayOfNumberOnly {
 
   public ArrayOfNumberOnly addArrayNumberItem(BigDecimal arrayNumberItem) {
     if (this.arrayNumber == null) {
-      this.arrayNumber = new ArrayList<BigDecimal>();
+      this.arrayNumber = new ArrayList<>();
     }
     this.arrayNumber.add(arrayNumberItem);
     return this;
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayTest.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayTest.java
index 62665c2536a..6804a14e313 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/ArrayTest.java
@@ -44,7 +44,7 @@ public class ArrayTest {
 
   public ArrayTest addArrayOfStringItem(String arrayOfStringItem) {
     if (this.arrayOfString == null) {
-      this.arrayOfString = new ArrayList<String>();
+      this.arrayOfString = new ArrayList<>();
     }
     this.arrayOfString.add(arrayOfStringItem);
     return this;
@@ -70,7 +70,7 @@ public class ArrayTest {
 
   public ArrayTest addArrayArrayOfIntegerItem(List<Long> arrayArrayOfIntegerItem) {
     if (this.arrayArrayOfInteger == null) {
-      this.arrayArrayOfInteger = new ArrayList<List<Long>>();
+      this.arrayArrayOfInteger = new ArrayList<>();
     }
     this.arrayArrayOfInteger.add(arrayArrayOfIntegerItem);
     return this;
@@ -96,7 +96,7 @@ public class ArrayTest {
 
   public ArrayTest addArrayArrayOfModelItem(List<ReadOnlyFirst> arrayArrayOfModelItem) {
     if (this.arrayArrayOfModel == null) {
-      this.arrayArrayOfModel = new ArrayList<List<ReadOnlyFirst>>();
+      this.arrayArrayOfModel = new ArrayList<>();
     }
     this.arrayArrayOfModel.add(arrayArrayOfModelItem);
     return this;
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/EnumArrays.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/EnumArrays.java
index 12caa480285..133a31f10b9 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/EnumArrays.java
@@ -128,7 +128,7 @@ public class EnumArrays {
 
   public EnumArrays addArrayEnumItem(ArrayEnumEnum arrayEnumItem) {
     if (this.arrayEnum == null) {
-      this.arrayEnum = new ArrayList<ArrayEnumEnum>();
+      this.arrayEnum = new ArrayList<>();
     }
     this.arrayEnum.add(arrayEnumItem);
     return this;
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/MapTest.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/MapTest.java
index e6344a1df0f..31a7dae7253 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/MapTest.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/MapTest.java
@@ -76,7 +76,7 @@ public class MapTest {
 
   public MapTest putMapMapOfStringItem(String key, Map<String, String> mapMapOfStringItem) {
     if (this.mapMapOfString == null) {
-      this.mapMapOfString = new HashMap<String, Map<String, String>>();
+      this.mapMapOfString = new HashMap<>();
     }
     this.mapMapOfString.put(key, mapMapOfStringItem);
     return this;
@@ -102,7 +102,7 @@ public class MapTest {
 
   public MapTest putMapOfEnumStringItem(String key, InnerEnum mapOfEnumStringItem) {
     if (this.mapOfEnumString == null) {
-      this.mapOfEnumString = new HashMap<String, InnerEnum>();
+      this.mapOfEnumString = new HashMap<>();
     }
     this.mapOfEnumString.put(key, mapOfEnumStringItem);
     return this;
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index b0736f316e3..98c2ad2cc78 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -83,7 +83,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
 
   public MixedPropertiesAndAdditionalPropertiesClass putMapItem(String key, Animal mapItem) {
     if (this.map == null) {
-      this.map = new HashMap<String, Animal>();
+      this.map = new HashMap<>();
     }
     this.map.put(key, mapItem);
     return this;
diff --git a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/Pet.java b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/Pet.java
index 4c351dec3e4..6ece90bbfc3 100644
--- a/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/Pet.java
+++ b/samples/client/petstore/java/jersey2-java8/src/main/java/io/swagger/client/model/Pet.java
@@ -39,7 +39,7 @@ public class Pet {
   private String name = null;
 
   @JsonProperty("photoUrls")
-  private List<String> photoUrls = new ArrayList<String>();
+  private List<String> photoUrls = new ArrayList<>();
 
   @JsonProperty("tags")
   private List<Tag> tags = null;
@@ -168,7 +168,7 @@ public class Pet {
 
   public Pet addTagsItem(Tag tagsItem) {
     if (this.tags == null) {
-      this.tags = new ArrayList<Tag>();
+      this.tags = new ArrayList<>();
     }
     this.tags.add(tagsItem);
     return this;