diff --git a/bin/java-petstore-rest-assured.sh b/bin/java-petstore-rest-assured.sh
index cacc3cf3c27..93de0703ed7 100755
--- a/bin/java-petstore-rest-assured.sh
+++ b/bin/java-petstore-rest-assured.sh
@@ -27,7 +27,7 @@ fi
 
 # if you've executed sbt assembly previously it will use that instead.
 export JAVA_OPTS="${JAVA_OPTS} -Xmx1024M -DloggerPath=conf/log4j.properties"
-ags="generate -t modules/openapi-generator/src/main/resources/Java/libraries/rest-assured -i modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -g java -c bin/java-petstore-rest-assured.json -o samples/client/petstore/java/rest-assured --additional-properties hideGenerationTimestamp=true --additional-properties booleanGetterPrefix=is $@"
+ags="generate -t modules/openapi-generator/src/main/resources/Java/libraries/rest-assured -i modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -g java -c bin/java-petstore-rest-assured.json -o samples/client/petstore/java/rest-assured --additional-properties hideGenerationTimestamp=true --additional-properties useBeanValidation=true --additional-properties performBeanValidation=true --additional-properties booleanGetterPrefix=is $@"
 
 echo "Removing files and folders under samples/client/petstore/java/rest-assured/src/main"
 rm -rf samples/client/petstore/java/rest-assured/src/main
diff --git a/docs/customization.md b/docs/customization.md
index 14fdd1a7f2c..fbdc5a890cd 100644
--- a/docs/customization.md
+++ b/docs/customization.md
@@ -248,7 +248,7 @@ CONFIG OPTIONS
 	    retrofit - HTTP client: OkHttp 2.4.0. JSON processing: Gson 2.3.1 (Retrofit 1.9.0)
         retrofit2 - HTTP client: OkHttp 2.5.0. JSON processing: Gson 2.4 (Retrofit 2.0.0-beta2)
         google-api-client - HTTP client: google-api-client 1.23.0. JSON processing: Jackson 2.8.9
-        rest-assured - HTTP client: rest-assured : 4.0.0. JSON processing: Gson 2.8.5. Only for Java8
+        rest-assured - HTTP client: rest-assured : 4.3.0. JSON processing: Gson 2.8.6. Only for Java8
 ```
 
 Your config file for Java can look like
diff --git a/docs/generators/java.md b/docs/generators/java.md
index c97d5e24d4e..9cac5e18dfe 100644
--- a/docs/generators/java.md
+++ b/docs/generators/java.md
@@ -28,7 +28,7 @@ sidebar_label: java
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |false|
 |invokerPackage|root package for generated code| |org.openapitools.client|
 |java8|Option. Use Java8 classes instead of third party equivalents|<dl><dt>**true**</dt><dd>Use Java 8 classes such as Base64</dd><dt>**false**</dt><dd>Various third party libraries as needed</dd></dl>|false|
-|library|library template (sub-template) to use|<dl><dt>**jersey1**</dt><dd>HTTP client: Jersey client 1.19.x. JSON processing: Jackson 2.9.x. Enable Java6 support using '-DsupportJava6=true'. Enable gzip request encoding using '-DuseGzipFeature=true'. IMPORTANT NOTE: jersey 1.x is no longer actively maintained so please upgrade to 'jersey2' or other HTTP libaries instead.</dd><dt>**jersey2**</dt><dd>HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.9.x</dd><dt>**feign**</dt><dd>HTTP client: OpenFeign 9.x (deprecated) or 10.x (default). JSON processing: Jackson 2.9.x.</dd><dt>**okhttp-gson**</dt><dd>[DEFAULT] HTTP client: OkHttp 3.x. JSON processing: Gson 2.8.x. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.</dd><dt>**retrofit**</dt><dd>HTTP client: OkHttp 2.x. JSON processing: Gson 2.x (Retrofit 1.9.0). IMPORTANT NOTE: retrofit1.x is no longer actively maintained so please upgrade to 'retrofit2' instead.</dd><dt>**retrofit2**</dt><dd>HTTP client: OkHttp 3.x. JSON processing: Gson 2.x (Retrofit 2.3.0). Enable the RxJava adapter using '-DuseRxJava[2]=true'. (RxJava 1.x or 2.x)</dd><dt>**resttemplate**</dt><dd>HTTP client: Spring RestTemplate 4.x. JSON processing: Jackson 2.9.x</dd><dt>**webclient**</dt><dd>HTTP client: Spring WebClient 5.x. JSON processing: Jackson 2.9.x</dd><dt>**resteasy**</dt><dd>HTTP client: Resteasy client 3.x. JSON processing: Jackson 2.9.x</dd><dt>**vertx**</dt><dd>HTTP client: VertX client 3.x. JSON processing: Jackson 2.9.x</dd><dt>**google-api-client**</dt><dd>HTTP client: Google API client 1.x. JSON processing: Jackson 2.9.x</dd><dt>**rest-assured**</dt><dd>HTTP client: rest-assured : 4.x. JSON processing: Gson 2.x or Jackson 2.9.x. Only for Java8</dd><dt>**native**</dt><dd>HTTP client: Java native HttpClient. JSON processing: Jackson 2.9.x. Only for Java11+</dd><dt>**microprofile**</dt><dd>HTTP client: Microprofile client X.x. JSON processing: Jackson 2.9.x</dd></dl>|okhttp-gson|
+|library|library template (sub-template) to use|<dl><dt>**jersey1**</dt><dd>HTTP client: Jersey client 1.19.x. JSON processing: Jackson 2.9.x. Enable Java6 support using '-DsupportJava6=true'. Enable gzip request encoding using '-DuseGzipFeature=true'. IMPORTANT NOTE: jersey 1.x is no longer actively maintained so please upgrade to 'jersey2' or other HTTP libaries instead.</dd><dt>**jersey2**</dt><dd>HTTP client: Jersey client 2.25.1. JSON processing: Jackson 2.9.x</dd><dt>**feign**</dt><dd>HTTP client: OpenFeign 9.x (deprecated) or 10.x (default). JSON processing: Jackson 2.9.x.</dd><dt>**okhttp-gson**</dt><dd>[DEFAULT] HTTP client: OkHttp 3.x. JSON processing: Gson 2.8.x. Enable Parcelable models on Android using '-DparcelableModel=true'. Enable gzip request encoding using '-DuseGzipFeature=true'.</dd><dt>**retrofit**</dt><dd>HTTP client: OkHttp 2.x. JSON processing: Gson 2.x (Retrofit 1.9.0). IMPORTANT NOTE: retrofit1.x is no longer actively maintained so please upgrade to 'retrofit2' instead.</dd><dt>**retrofit2**</dt><dd>HTTP client: OkHttp 3.x. JSON processing: Gson 2.x (Retrofit 2.3.0). Enable the RxJava adapter using '-DuseRxJava[2]=true'. (RxJava 1.x or 2.x)</dd><dt>**resttemplate**</dt><dd>HTTP client: Spring RestTemplate 4.x. JSON processing: Jackson 2.9.x</dd><dt>**webclient**</dt><dd>HTTP client: Spring WebClient 5.x. JSON processing: Jackson 2.9.x</dd><dt>**resteasy**</dt><dd>HTTP client: Resteasy client 3.x. JSON processing: Jackson 2.9.x</dd><dt>**vertx**</dt><dd>HTTP client: VertX client 3.x. JSON processing: Jackson 2.9.x</dd><dt>**google-api-client**</dt><dd>HTTP client: Google API client 1.x. JSON processing: Jackson 2.9.x</dd><dt>**rest-assured**</dt><dd>HTTP client: rest-assured : 4.x. JSON processing: Gson 2.x or Jackson 2.10.x. Only for Java 8</dd><dt>**native**</dt><dd>HTTP client: Java native HttpClient. JSON processing: Jackson 2.9.x. Only for Java11+</dd><dt>**microprofile**</dt><dd>HTTP client: Microprofile client X.x. JSON processing: Jackson 2.9.x</dd></dl>|okhttp-gson|
 |licenseName|The name of the license| |Unlicense|
 |licenseUrl|The URL of the license| |http://unlicense.org|
 |modelPackage|package for generated models| |org.openapitools.client.model|
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
index 8836f1b7e66..58134a28b1e 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java
@@ -153,7 +153,7 @@ public class JavaClientCodegen extends AbstractJavaCodegen
         supportedLibraries.put(RESTEASY, "HTTP client: Resteasy client 3.x. JSON processing: Jackson 2.9.x");
         supportedLibraries.put(VERTX, "HTTP client: VertX client 3.x. JSON processing: Jackson 2.9.x");
         supportedLibraries.put(GOOGLE_API_CLIENT, "HTTP client: Google API client 1.x. JSON processing: Jackson 2.9.x");
-        supportedLibraries.put(REST_ASSURED, "HTTP client: rest-assured : 4.x. JSON processing: Gson 2.x or Jackson 2.9.x. Only for Java8");
+        supportedLibraries.put(REST_ASSURED, "HTTP client: rest-assured : 4.x. JSON processing: Gson 2.x or Jackson 2.10.x. Only for Java 8");
         supportedLibraries.put(NATIVE, "HTTP client: Java native HttpClient. JSON processing: Jackson 2.9.x. Only for Java11+");
         supportedLibraries.put(MICROPROFILE, "HTTP client: Microprofile client X.x. JSON processing: Jackson 2.9.x");
 
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/build.gradle.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/build.gradle.mustache
index b04e53f1e96..640ad1cd18c 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/build.gradle.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/build.gradle.mustache
@@ -96,24 +96,24 @@ if(hasProperty('target') && target == 'android') {
 
 ext {
     swagger_annotations_version = "1.5.21"
-    rest_assured_version = "4.0.0"
+    rest_assured_version = "4.3.0"
     junit_version = "4.13"
 {{#jackson}}
-    jackson_version = "2.10.1"
-    jackson_databind_version = "2.9.10"
+    jackson_version = "2.10.3"
+    jackson_databind_version = "2.10.3"
     jackson_databind_nullable_version = 0.2.1
 {{/jackson}}
 {{#gson}}
-    gson_version = "2.8.5"
-    gson_fire_version = "1.8.3"
+    gson_version = "2.8.6"
+    gson_fire_version = "1.8.4"
 {{/gson}}
 {{#joda}}
-    jodatime_version = "2.9.9"
+    jodatime_version = "2.10.5"
 {{/joda}}
 {{#threetenbp}}
-    threetenbp_version = "1.4.0"
+    threetenbp_version = "1.4.3"
 {{/threetenbp}}
-    okio_version = "1.13.0"
+    okio_version = "1.17.5"
 }
 
 dependencies {
@@ -138,5 +138,11 @@ dependencies {
     compile "org.threeten:threetenbp:$threetenbp_version"
 {{/threetenbp}}
     compile "com.squareup.okio:okio:$okio_version"
+{{#useBeanValidation}}
+    compile "javax.validation:validation-api:2.0.1.Final"
+{{/useBeanValidation}}
+{{#performBeanValidation}}
+    compile "org.hibernate:hibernate-validator:6.0.19.Final"
+{{/performBeanValidation}}
     testCompile "junit:junit:$junit_version"
 }
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/build.sbt.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/build.sbt.mustache
index 71f2eaeeba2..77f8af4f436 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/build.sbt.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/build.sbt.mustache
@@ -10,23 +10,29 @@ lazy val root = (project in file(".")).
     resolvers += Resolver.mavenLocal,
     libraryDependencies ++= Seq(
       "io.swagger" % "swagger-annotations" % "1.5.21",
-      "io.rest-assured" % "scala-support" % "4.0.0",
+      "io.rest-assured" % "scala-support" % "4.3.0",
 {{#jackson}}
-      "com.fasterxml.jackson.core" % "jackson-core" % "2.9.9" % "compile",
-      "com.fasterxml.jackson.core" % "jackson-annotations" % "2.9.9" % "compile",
-      "com.fasterxml.jackson.core" % "jackson-databind" % "2.9.9" % "compile",
+      "com.fasterxml.jackson.core" % "jackson-core" % "2.10.3" % "compile",
+      "com.fasterxml.jackson.core" % "jackson-annotations" % "2.10.3" % "compile",
+      "com.fasterxml.jackson.core" % "jackson-databind" % "2.10.3" % "compile",
 {{/jackson}}
 {{#gson}}
-      "com.google.code.gson" % "gson" % "2.8.5",
-      "io.gsonfire" % "gson-fire" % "1.8.3" % "compile",
+      "com.google.code.gson" % "gson" % "2.8.6",
+      "io.gsonfire" % "gson-fire" % "1.8.4" % "compile",
 {{/gson}}
 {{#joda}}
-      "joda-time" % "joda-time" % "2.9.9" % "compile",
+      "joda-time" % "joda-time" % "2.10.5" % "compile",
 {{/joda}}
 {{#threetenbp}}
-      "org.threeten" % "threetenbp" % "1.4.0" % "compile",
+      "org.threeten" % "threetenbp" % "1.4.3" % "compile",
 {{/threetenbp}}
-      "com.squareup.okio" % "okio" % "1.13.0" % "compile",
+      "com.squareup.okio" % "okio" % "1.17.5" % "compile",
+{{#useBeanValidation}}
+      "javax.validation" % "validation-api" % "2.0.1.Final" % "compile",
+{{/useBeanValidation}}
+{{#performBeanValidation}}
+      "org.hibernate" % "hibernate-validator" "6.0.19.Final" % "compile",
+{{/performBeanValidation}}
       "junit" % "junit" % "4.13" % "test",
       "com.novocode" % "junit-interface" % "0.10" % "test"
     )
diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/pom.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/pom.mustache
index da538caa9b0..2e68695d431 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/pom.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/rest-assured/pom.mustache
@@ -43,7 +43,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-enforcer-plugin</artifactId>
-                <version>3.0.0-M1</version>
+                <version>3.0.0-M3</version>
                 <executions>
                     <execution>
                         <id>enforce-maven</id>
@@ -53,7 +53,7 @@
                         <configuration>
                             <rules>
                                 <requireMavenVersion>
-                                    <version>2.2.0</version>
+                                    <version>3.0.5</version>
                                 </requireMavenVersion>
                             </rules>
                         </configuration>
@@ -63,7 +63,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>2.12</version>
+                <version>2.22.2</version>
                 <configuration>
                     <systemProperties>
                         <property>
@@ -71,9 +71,8 @@
                             <value>conf/log4j.properties</value>
                         </property>
                     </systemProperties>
-                    <argLine>-Xms512m -Xmx1500m</argLine>
-                    <parallel>methods</parallel>
-                    <forkMode>pertest</forkMode>
+                    <reuseForks>false</reuseForks>
+                    <forkCount>1C</forkCount>
                 </configuration>
             </plugin>
             <plugin>
@@ -111,6 +110,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>build-helper-maven-plugin</artifactId>
+                <version>3.1.0</version>
                 <executions>
                     <execution>
                         <id>add_sources</id>
@@ -141,7 +141,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.6.1</version>
+                <version>3.8.1</version>
                 <configuration>
                     <source>1.8</source>
                     <target>1.8</target>
@@ -150,7 +150,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
-                <version>3.1.1</version>
+                <version>3.2.0</version>
                 <configuration>
                     <doclint>none</doclint>
                 </configuration>
@@ -166,7 +166,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-source-plugin</artifactId>
-                <version>2.2.1</version>
+                <version>3.2.0</version>
                 <executions>
                     <execution>
                         <id>attach-sources</id>
@@ -187,7 +187,7 @@
                     <plugin>
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-gpg-plugin</artifactId>
-                        <version>1.5</version>
+                        <version>1.6</version>
                         <executions>
                             <execution>
                                 <id>sign-artifacts</id>
@@ -203,6 +203,20 @@
         </profile>
     </profiles>
 
+    {{#jackson}}
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>com.fasterxml.jackson</groupId>
+                <artifactId>jackson-bom</artifactId>
+                <version>${jackson-version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+    {{/jackson}}
+
     <dependencies>
         <dependency>
             <groupId>io.swagger</groupId>
@@ -215,6 +229,14 @@
             <artifactId>jsr305</artifactId>
             <version>3.0.2</version>
         </dependency>
+        {{^hideGenerationTimestamp}}
+        <dependency>
+            <groupId>javax.annotation</groupId>
+            <artifactId>javax.annotation-api</artifactId>
+            <version>1.3.2</version>
+            <scope>provided</scope>
+        </dependency>
+        {{/hideGenerationTimestamp}}
         <dependency>
             <groupId>io.rest-assured</groupId>
             <artifactId>rest-assured</artifactId>
@@ -253,17 +275,14 @@
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-core</artifactId>
-            <version>${jackson-version}</version>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-annotations</artifactId>
-            <version>${jackson-version}</version>
         </dependency>
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>
-            <version>${jackson-databind-version}</version>
         </dependency>
         <dependency>
             <groupId>org.openapitools</groupId>
@@ -274,21 +293,18 @@
         <dependency>
             <groupId>com.fasterxml.jackson.dataformat</groupId>
             <artifactId>jackson-dataformat-xml</artifactId>
-            <version>${jackson-version}</version>
         </dependency>
         {{/withXml}}
         {{#joda}}
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>
             <artifactId>jackson-datatype-joda</artifactId>
-            <version>${jackson-version}</version>
         </dependency>
         {{/joda}}
         {{#java8}}
         <dependency>
             <groupId>com.fasterxml.jackson.datatype</groupId>
             <artifactId>jackson-datatype-jsr310</artifactId>
-            <version>${jackson-version}</version>
         </dependency>
         {{/java8}}
         {{#threetenbp}}
@@ -304,6 +320,23 @@
             <artifactId>okio</artifactId>
             <version>${okio-version}</version>
         </dependency>
+        {{#useBeanValidation}}
+        <!-- Bean Validation API support -->
+        <dependency>
+            <groupId>javax.validation</groupId>
+            <artifactId>validation-api</artifactId>
+            <version>2.0.1.Final</version>
+            <scope>provided</scope>
+        </dependency>
+        {{/useBeanValidation}}
+        {{#performBeanValidation}}
+        <!-- Bean Validation Impl. used to perform BeanValidation -->
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-validator</artifactId>
+            <version>6.0.19.Final</version>
+        </dependency>
+        {{/performBeanValidation}}
         <!-- test dependencies -->
         <dependency>
             <groupId>junit</groupId>
@@ -315,25 +348,23 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <swagger-annotations-version>1.5.21</swagger-annotations-version>
-        <rest-assured.version>4.0.0</rest-assured.version>
-        <gson-version>2.8.5</gson-version>
-        <gson-fire-version>1.8.3</gson-fire-version>
-        <maven-plugin-version>1.0.0</maven-plugin-version>
+        <rest-assured.version>4.3.0</rest-assured.version>
+        <gson-version>2.8.6</gson-version>
+        <gson-fire-version>1.8.4</gson-fire-version>
         {{#joda}}
-        <jodatime-version>2.9.9</jodatime-version>
+        <jodatime-version>2.10.5</jodatime-version>
         {{/joda}}
         {{#threetenbp}}
-        <threetenbp-version>1.4.0</threetenbp-version>
+        <threetenbp-version>1.4.3</threetenbp-version>
         {{/threetenbp}}
         {{#jackson}}
-        <jackson-version>2.10.1</jackson-version>
-        <jackson-databind-version>2.9.10</jackson-databind-version>
+        <jackson-version>2.10.3</jackson-version>
         <jackson-databind-nullable-version>0.2.1</jackson-databind-nullable-version>
         {{#threetenbp}}
-        <jackson-threetenbp-version>2.9.10</jackson-threetenbp-version>
+        <jackson-threetenbp-version>2.10.0</jackson-threetenbp-version>
         {{/threetenbp}}
         {{/jackson}}
-        <okio-version>1.13.0</okio-version>
+        <okio-version>1.17.5</okio-version>
         <junit-version>4.13</junit-version>
     </properties>
 </project>
diff --git a/samples/client/petstore/java/rest-assured/build.gradle b/samples/client/petstore/java/rest-assured/build.gradle
index 67c6d784de8..015b0b676a8 100644
--- a/samples/client/petstore/java/rest-assured/build.gradle
+++ b/samples/client/petstore/java/rest-assured/build.gradle
@@ -96,12 +96,12 @@ if(hasProperty('target') && target == 'android') {
 
 ext {
     swagger_annotations_version = "1.5.21"
-    rest_assured_version = "4.0.0"
+    rest_assured_version = "4.3.0"
     junit_version = "4.13"
-    gson_version = "2.8.5"
-    gson_fire_version = "1.8.3"
-    threetenbp_version = "1.4.0"
-    okio_version = "1.13.0"
+    gson_version = "2.8.6"
+    gson_fire_version = "1.8.4"
+    threetenbp_version = "1.4.3"
+    okio_version = "1.17.5"
 }
 
 dependencies {
@@ -112,5 +112,7 @@ dependencies {
     compile 'com.google.code.gson:gson:$gson_version'
     compile "org.threeten:threetenbp:$threetenbp_version"
     compile "com.squareup.okio:okio:$okio_version"
+    compile "javax.validation:validation-api:2.0.1.Final"
+    compile "org.hibernate:hibernate-validator:6.0.19.Final"
     testCompile "junit:junit:$junit_version"
 }
diff --git a/samples/client/petstore/java/rest-assured/build.sbt b/samples/client/petstore/java/rest-assured/build.sbt
index 8777fcab7f5..980585522a9 100644
--- a/samples/client/petstore/java/rest-assured/build.sbt
+++ b/samples/client/petstore/java/rest-assured/build.sbt
@@ -10,11 +10,13 @@ lazy val root = (project in file(".")).
     resolvers += Resolver.mavenLocal,
     libraryDependencies ++= Seq(
       "io.swagger" % "swagger-annotations" % "1.5.21",
-      "io.rest-assured" % "scala-support" % "4.0.0",
-      "com.google.code.gson" % "gson" % "2.8.5",
-      "io.gsonfire" % "gson-fire" % "1.8.3" % "compile",
-      "org.threeten" % "threetenbp" % "1.4.0" % "compile",
-      "com.squareup.okio" % "okio" % "1.13.0" % "compile",
+      "io.rest-assured" % "scala-support" % "4.3.0",
+      "com.google.code.gson" % "gson" % "2.8.6",
+      "io.gsonfire" % "gson-fire" % "1.8.4" % "compile",
+      "org.threeten" % "threetenbp" % "1.4.3" % "compile",
+      "com.squareup.okio" % "okio" % "1.17.5" % "compile",
+      "javax.validation" % "validation-api" % "2.0.1.Final" % "compile",
+      "org.hibernate" % "hibernate-validator" "6.0.19.Final" % "compile",
       "junit" % "junit" % "4.13" % "test",
       "com.novocode" % "junit-interface" % "0.10" % "test"
     )
diff --git a/samples/client/petstore/java/rest-assured/pom.xml b/samples/client/petstore/java/rest-assured/pom.xml
index ffa51be6c21..21e224499c4 100644
--- a/samples/client/petstore/java/rest-assured/pom.xml
+++ b/samples/client/petstore/java/rest-assured/pom.xml
@@ -36,7 +36,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-enforcer-plugin</artifactId>
-                <version>3.0.0-M1</version>
+                <version>3.0.0-M3</version>
                 <executions>
                     <execution>
                         <id>enforce-maven</id>
@@ -46,7 +46,7 @@
                         <configuration>
                             <rules>
                                 <requireMavenVersion>
-                                    <version>2.2.0</version>
+                                    <version>3.0.5</version>
                                 </requireMavenVersion>
                             </rules>
                         </configuration>
@@ -56,7 +56,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>2.12</version>
+                <version>2.22.2</version>
                 <configuration>
                     <systemProperties>
                         <property>
@@ -64,9 +64,8 @@
                             <value>conf/log4j.properties</value>
                         </property>
                     </systemProperties>
-                    <argLine>-Xms512m -Xmx1500m</argLine>
-                    <parallel>methods</parallel>
-                    <forkMode>pertest</forkMode>
+                    <reuseForks>false</reuseForks>
+                    <forkCount>1C</forkCount>
                 </configuration>
             </plugin>
             <plugin>
@@ -104,6 +103,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>build-helper-maven-plugin</artifactId>
+                <version>3.1.0</version>
                 <executions>
                     <execution>
                         <id>add_sources</id>
@@ -134,7 +134,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.6.1</version>
+                <version>3.8.1</version>
                 <configuration>
                     <source>1.8</source>
                     <target>1.8</target>
@@ -143,7 +143,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
-                <version>3.1.1</version>
+                <version>3.2.0</version>
                 <configuration>
                     <doclint>none</doclint>
                 </configuration>
@@ -159,7 +159,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-source-plugin</artifactId>
-                <version>2.2.1</version>
+                <version>3.2.0</version>
                 <executions>
                     <execution>
                         <id>attach-sources</id>
@@ -180,7 +180,7 @@
                     <plugin>
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-gpg-plugin</artifactId>
-                        <version>1.5</version>
+                        <version>1.6</version>
                         <executions>
                             <execution>
                                 <id>sign-artifacts</id>
@@ -196,6 +196,7 @@
         </profile>
     </profiles>
 
+
     <dependencies>
         <dependency>
             <groupId>io.swagger</groupId>
@@ -233,6 +234,19 @@
             <artifactId>okio</artifactId>
             <version>${okio-version}</version>
         </dependency>
+        <!-- Bean Validation API support -->
+        <dependency>
+            <groupId>javax.validation</groupId>
+            <artifactId>validation-api</artifactId>
+            <version>2.0.1.Final</version>
+            <scope>provided</scope>
+        </dependency>
+        <!-- Bean Validation Impl. used to perform BeanValidation -->
+        <dependency>
+            <groupId>org.hibernate</groupId>
+            <artifactId>hibernate-validator</artifactId>
+            <version>6.0.19.Final</version>
+        </dependency>
         <!-- test dependencies -->
         <dependency>
             <groupId>junit</groupId>
@@ -244,12 +258,11 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <swagger-annotations-version>1.5.21</swagger-annotations-version>
-        <rest-assured.version>4.0.0</rest-assured.version>
-        <gson-version>2.8.5</gson-version>
-        <gson-fire-version>1.8.3</gson-fire-version>
-        <maven-plugin-version>1.0.0</maven-plugin-version>
-        <threetenbp-version>1.4.0</threetenbp-version>
-        <okio-version>1.13.0</okio-version>
+        <rest-assured.version>4.3.0</rest-assured.version>
+        <gson-version>2.8.6</gson-version>
+        <gson-fire-version>1.8.4</gson-fire-version>
+        <threetenbp-version>1.4.3</threetenbp-version>
+        <okio-version>1.17.5</okio-version>
         <junit-version>4.13</junit-version>
     </properties>
 </project>
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/BeanValidationException.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/BeanValidationException.java
new file mode 100644
index 00000000000..28b41ac559e
--- /dev/null
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/BeanValidationException.java
@@ -0,0 +1,27 @@
+package org.openapitools.client;
+
+import java.util.Set;
+
+import javax.validation.ConstraintViolation;
+import javax.validation.ValidationException;
+
+public class BeanValidationException extends ValidationException {
+    /**
+     * 
+     */
+    private static final long serialVersionUID = -5294733947409491364L;
+    Set<ConstraintViolation<Object>> violations;
+
+    public BeanValidationException(Set<ConstraintViolation<Object>> violations) {
+        this.violations = violations;
+    }
+
+    public Set<ConstraintViolation<Object>> getViolations() {
+        return violations;
+    }
+
+    public void setViolations(Set<ConstraintViolation<Object>> violations) {
+        this.violations = violations;
+    }
+
+}
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
index 79c169543fd..aba19948f05 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesAnyType.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * AdditionalPropertiesAnyType
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
index e16ee861f89..bb35b0970ef 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesArray.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * AdditionalPropertiesArray
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
index 29161b52aa1..b3528f7a872 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesBoolean.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * AdditionalPropertiesBoolean
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
index a067b01ec97..9b270abdb56 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesClass.java
@@ -27,6 +27,9 @@ import java.math.BigDecimal;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * AdditionalPropertiesClass
@@ -128,6 +131,7 @@ public class AdditionalPropertiesClass {
    * @return mapNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Map<String, BigDecimal> getMapNumber() {
@@ -221,6 +225,7 @@ public class AdditionalPropertiesClass {
    * @return mapArrayInteger
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Map<String, List<Integer>> getMapArrayInteger() {
@@ -252,6 +257,7 @@ public class AdditionalPropertiesClass {
    * @return mapArrayAnytype
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Map<String, List<Object>> getMapArrayAnytype() {
@@ -283,6 +289,7 @@ public class AdditionalPropertiesClass {
    * @return mapMapString
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Map<String, Map<String, String>> getMapMapString() {
@@ -314,6 +321,7 @@ public class AdditionalPropertiesClass {
    * @return mapMapAnytype
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Map<String, Map<String, Object>> getMapMapAnytype() {
@@ -337,6 +345,7 @@ public class AdditionalPropertiesClass {
    * @return anytype1
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Object getAnytype1() {
@@ -360,6 +369,7 @@ public class AdditionalPropertiesClass {
    * @return anytype2
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Object getAnytype2() {
@@ -383,6 +393,7 @@ public class AdditionalPropertiesClass {
    * @return anytype3
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Object getAnytype3() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
index 3a15ed7cd97..574b6ad8f1b 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesInteger.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * AdditionalPropertiesInteger
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
index 9bc46e09991..c138d835e55 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesNumber.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.math.BigDecimal;
 import java.util.HashMap;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * AdditionalPropertiesNumber
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
index bd65f7791c5..48bd74a65a6 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesObject.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * AdditionalPropertiesObject
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
index cdb8afedaaf..8be8dcd782d 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/AdditionalPropertiesString.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * AdditionalPropertiesString
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Animal.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Animal.java
index af469dda3f4..bb64354ab52 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Animal.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Animal.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Animal
@@ -52,6 +55,7 @@ public class Animal {
    * Get className
    * @return className
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public String getClassName() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
index a6dd760660d..9db163e7153 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfArrayOfNumberOnly.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * ArrayOfArrayOfNumberOnly
@@ -56,6 +59,7 @@ public class ArrayOfArrayOfNumberOnly {
    * @return arrayArrayNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public List<List<BigDecimal>> getArrayArrayNumber() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
index 487c539d3ba..02106b473bc 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayOfNumberOnly.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * ArrayOfNumberOnly
@@ -56,6 +59,7 @@ public class ArrayOfNumberOnly {
    * @return arrayNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public List<BigDecimal> getArrayNumber() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
index 7d66ce233fe..4ec8e611d8c 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ArrayTest.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import org.openapitools.client.model.ReadOnlyFirst;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * ArrayTest
@@ -95,6 +98,7 @@ public class ArrayTest {
    * @return arrayArrayOfInteger
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public List<List<Long>> getArrayArrayOfInteger() {
@@ -126,6 +130,7 @@ public class ArrayTest {
    * @return arrayArrayOfModel
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public List<List<ReadOnlyFirst>> getArrayArrayOfModel() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCat.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCat.java
index 74b7ddc8135..14436bf9f98 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCat.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCat.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import org.openapitools.client.model.BigCatAllOf;
 import org.openapitools.client.model.Cat;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * BigCat
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCatAllOf.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCatAllOf.java
index cd2207704bd..eaa29645102 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCatAllOf.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/BigCatAllOf.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * BigCatAllOf
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Capitalization.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Capitalization.java
index d4fbec81c54..90db42f1963 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Capitalization.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Capitalization.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Capitalization
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Cat.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Cat.java
index e5a45ef03d8..1d89f2afd13 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Cat.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Cat.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import org.openapitools.client.model.Animal;
 import org.openapitools.client.model.CatAllOf;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Cat
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/CatAllOf.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/CatAllOf.java
index 3299c8ea877..6061abfee80 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/CatAllOf.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/CatAllOf.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * CatAllOf
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Category.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Category.java
index 4d07c3a1bef..1837174952a 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Category.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Category.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Category
@@ -71,6 +74,7 @@ public class Category {
    * Get name
    * @return name
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public String getName() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ClassModel.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ClassModel.java
index 8867bdd06bf..8bda0bd8381 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ClassModel.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ClassModel.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Model for testing model with \&quot;_class\&quot; property
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Client.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Client.java
index 25831260e09..e72113def90 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Client.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Client.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Client
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Dog.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Dog.java
index 89c8b6aba99..174de6bb5be 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Dog.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Dog.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import org.openapitools.client.model.Animal;
 import org.openapitools.client.model.DogAllOf;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Dog
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/DogAllOf.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/DogAllOf.java
index b945c2c33db..dc2f0f751e6 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/DogAllOf.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/DogAllOf.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * DogAllOf
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
index 2512b4cf9d5..0fd2de659e9 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumArrays.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * EnumArrays
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumClass.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumClass.java
index b9a78241a5a..ae6366ff619 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumClass.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumClass.java
@@ -16,6 +16,9 @@ package org.openapitools.client.model;
 import java.util.Objects;
 import java.util.Arrays;
 import com.google.gson.annotations.SerializedName;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 import java.io.IOException;
 import com.google.gson.TypeAdapter;
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumTest.java
index ccbbabaa9ba..5fa3c853a03 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/EnumTest.java
@@ -24,6 +24,9 @@ import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import org.openapitools.client.model.OuterEnum;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * EnumTest
@@ -276,6 +279,7 @@ public class EnumTest {
    * Get enumStringRequired
    * @return enumStringRequired
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public EnumStringRequiredEnum getEnumStringRequired() {
@@ -345,6 +349,7 @@ public class EnumTest {
    * @return outerEnum
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public OuterEnum getOuterEnum() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
index f4a15cd5b7f..eb73f8f1e4a 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FileSchemaTestClass.java
@@ -25,6 +25,9 @@ import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * FileSchemaTestClass
@@ -51,6 +54,7 @@ public class FileSchemaTestClass {
    * @return file
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public java.io.File getFile() {
@@ -82,6 +86,7 @@ public class FileSchemaTestClass {
    * @return files
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public List<java.io.File> getFiles() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FormatTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FormatTest.java
index 5983420c81b..c05d5a9485e 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FormatTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/FormatTest.java
@@ -28,6 +28,9 @@ import java.math.BigDecimal;
 import java.util.UUID;
 import org.threeten.bp.LocalDate;
 import org.threeten.bp.OffsetDateTime;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * FormatTest
@@ -104,7 +107,7 @@ public class FormatTest {
    * @return integer
   **/
   @javax.annotation.Nullable
-  @ApiModelProperty(value = "")
+ @Min(10) @Max(100)  @ApiModelProperty(value = "")
 
   public Integer getInteger() {
     return integer;
@@ -129,7 +132,7 @@ public class FormatTest {
    * @return int32
   **/
   @javax.annotation.Nullable
-  @ApiModelProperty(value = "")
+ @Min(20) @Max(200)  @ApiModelProperty(value = "")
 
   public Integer getInt32() {
     return int32;
@@ -176,7 +179,9 @@ public class FormatTest {
    * maximum: 543.2
    * @return number
   **/
-  @ApiModelProperty(required = true, value = "")
+  @NotNull
+  @Valid
+ @DecimalMin("32.1") @DecimalMax("543.2")  @ApiModelProperty(required = true, value = "")
 
   public BigDecimal getNumber() {
     return number;
@@ -201,7 +206,7 @@ public class FormatTest {
    * @return _float
   **/
   @javax.annotation.Nullable
-  @ApiModelProperty(value = "")
+ @DecimalMin("54.3") @DecimalMax("987.6")  @ApiModelProperty(value = "")
 
   public Float getFloat() {
     return _float;
@@ -226,7 +231,7 @@ public class FormatTest {
    * @return _double
   **/
   @javax.annotation.Nullable
-  @ApiModelProperty(value = "")
+ @DecimalMin("67.8") @DecimalMax("123.4")  @ApiModelProperty(value = "")
 
   public Double getDouble() {
     return _double;
@@ -249,7 +254,7 @@ public class FormatTest {
    * @return string
   **/
   @javax.annotation.Nullable
-  @ApiModelProperty(value = "")
+ @Pattern(regexp="/[a-z]/i")  @ApiModelProperty(value = "")
 
   public String getString() {
     return string;
@@ -271,7 +276,8 @@ public class FormatTest {
    * Get _byte
    * @return _byte
   **/
-  @ApiModelProperty(required = true, value = "")
+  @NotNull
+ @Pattern(regexp="^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$")  @ApiModelProperty(required = true, value = "")
 
   public byte[] getByte() {
     return _byte;
@@ -294,6 +300,7 @@ public class FormatTest {
    * @return binary
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public File getBinary() {
@@ -316,6 +323,8 @@ public class FormatTest {
    * Get date
    * @return date
   **/
+  @NotNull
+  @Valid
   @ApiModelProperty(required = true, value = "")
 
   public LocalDate getDate() {
@@ -339,6 +348,7 @@ public class FormatTest {
    * @return dateTime
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public OffsetDateTime getDateTime() {
@@ -362,6 +372,7 @@ public class FormatTest {
    * @return uuid
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(example = "72f98069-206d-4f12-9f12-3d1e525a8e84", value = "")
 
   public UUID getUuid() {
@@ -384,7 +395,8 @@ public class FormatTest {
    * Get password
    * @return password
   **/
-  @ApiModelProperty(required = true, value = "")
+  @NotNull
+ @Size(min=10,max=64)  @ApiModelProperty(required = true, value = "")
 
   public String getPassword() {
     return password;
@@ -407,6 +419,7 @@ public class FormatTest {
    * @return bigDecimal
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public BigDecimal getBigDecimal() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
index 8fcb2684643..b5f9d033d1f 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/HasOnlyReadOnly.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * HasOnlyReadOnly
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MapTest.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MapTest.java
index 7dc68b0ff00..d2d1452e028 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MapTest.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MapTest.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * MapTest
@@ -115,6 +118,7 @@ public class MapTest {
    * @return mapMapOfString
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Map<String, Map<String, String>> getMapMapOfString() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 527853d7522..ee8f4a7f9bb 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -29,6 +29,9 @@ import java.util.Map;
 import java.util.UUID;
 import org.openapitools.client.model.Animal;
 import org.threeten.bp.OffsetDateTime;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * MixedPropertiesAndAdditionalPropertiesClass
@@ -59,6 +62,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * @return uuid
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public UUID getUuid() {
@@ -82,6 +86,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * @return dateTime
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public OffsetDateTime getDateTime() {
@@ -113,6 +118,7 @@ public class MixedPropertiesAndAdditionalPropertiesClass {
    * @return map
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Map<String, Animal> getMap() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Model200Response.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Model200Response.java
index df3683dac78..55328ed3acc 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Model200Response.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Model200Response.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Model for testing model name starting with number
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelApiResponse.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelApiResponse.java
index b9cf72823b2..9fb06422b55 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelApiResponse.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelApiResponse.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * ModelApiResponse
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelReturn.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelReturn.java
index 6e9714df977..84afadc7439 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelReturn.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ModelReturn.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Model for testing reserved words
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Name.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Name.java
index 94117a9b0f4..ddea46f4bf1 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Name.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Name.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Model for testing model name same as property name
@@ -57,6 +60,7 @@ public class Name {
    * Get name
    * @return name
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public Integer getName() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/NumberOnly.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/NumberOnly.java
index 9a55d8aa615..5ea3f679be6 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/NumberOnly.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/NumberOnly.java
@@ -24,6 +24,9 @@ import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.math.BigDecimal;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * NumberOnly
@@ -46,6 +49,7 @@ public class NumberOnly {
    * @return justNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public BigDecimal getJustNumber() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Order.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Order.java
index 4e41a3dc88e..40eed7b5db9 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Order.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Order.java
@@ -24,6 +24,9 @@ import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import org.threeten.bp.OffsetDateTime;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Order
@@ -184,6 +187,7 @@ public class Order {
    * @return shipDate
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public OffsetDateTime getShipDate() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterComposite.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterComposite.java
index 96b1237f82f..fef7f5812aa 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterComposite.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterComposite.java
@@ -24,6 +24,9 @@ import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
 import java.math.BigDecimal;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * OuterComposite
@@ -54,6 +57,7 @@ public class OuterComposite {
    * @return myNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public BigDecimal getMyNumber() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterEnum.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterEnum.java
index bd870812102..be690856408 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterEnum.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/OuterEnum.java
@@ -16,6 +16,9 @@ package org.openapitools.client.model;
 import java.util.Objects;
 import java.util.Arrays;
 import com.google.gson.annotations.SerializedName;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 import java.io.IOException;
 import com.google.gson.TypeAdapter;
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
index e50743626b4..a20c1cfcdd5 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Pet.java
@@ -27,6 +27,9 @@ import java.util.ArrayList;
 import java.util.List;
 import org.openapitools.client.model.Category;
 import org.openapitools.client.model.Tag;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Pet
@@ -141,6 +144,7 @@ public class Pet {
    * @return category
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public Category getCategory() {
@@ -163,6 +167,7 @@ public class Pet {
    * Get name
    * @return name
   **/
+  @NotNull
   @ApiModelProperty(example = "doggie", required = true, value = "")
 
   public String getName() {
@@ -190,6 +195,7 @@ public class Pet {
    * Get photoUrls
    * @return photoUrls
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public List<String> getPhotoUrls() {
@@ -221,6 +227,7 @@ public class Pet {
    * @return tags
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(value = "")
 
   public List<Tag> getTags() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
index ed0244a3ca2..d034413519b 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/ReadOnlyFirst.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * ReadOnlyFirst
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/SpecialModelName.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/SpecialModelName.java
index 3405d30ff61..45f9e21f8b6 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/SpecialModelName.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/SpecialModelName.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * SpecialModelName
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Tag.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Tag.java
index 710e0fe54a4..315b9180f67 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Tag.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/Tag.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * Tag
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderDefault.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
index b6cea1fd768..bbe170f1984 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderDefault.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * TypeHolderDefault
@@ -63,6 +66,7 @@ public class TypeHolderDefault {
    * Get stringItem
    * @return stringItem
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public String getStringItem() {
@@ -85,6 +89,8 @@ public class TypeHolderDefault {
    * Get numberItem
    * @return numberItem
   **/
+  @NotNull
+  @Valid
   @ApiModelProperty(required = true, value = "")
 
   public BigDecimal getNumberItem() {
@@ -107,6 +113,7 @@ public class TypeHolderDefault {
    * Get integerItem
    * @return integerItem
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public Integer getIntegerItem() {
@@ -129,6 +136,7 @@ public class TypeHolderDefault {
    * Get boolItem
    * @return boolItem
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public Boolean isBoolItem() {
@@ -156,6 +164,7 @@ public class TypeHolderDefault {
    * Get arrayItem
    * @return arrayItem
   **/
+  @NotNull
   @ApiModelProperty(required = true, value = "")
 
   public List<Integer> getArrayItem() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderExample.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderExample.java
index 787d0123cce..daa84d59ba9 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderExample.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/TypeHolderExample.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * TypeHolderExample
@@ -67,6 +70,7 @@ public class TypeHolderExample {
    * Get stringItem
    * @return stringItem
   **/
+  @NotNull
   @ApiModelProperty(example = "what", required = true, value = "")
 
   public String getStringItem() {
@@ -89,6 +93,8 @@ public class TypeHolderExample {
    * Get numberItem
    * @return numberItem
   **/
+  @NotNull
+  @Valid
   @ApiModelProperty(example = "1.234", required = true, value = "")
 
   public BigDecimal getNumberItem() {
@@ -111,6 +117,7 @@ public class TypeHolderExample {
    * Get floatItem
    * @return floatItem
   **/
+  @NotNull
   @ApiModelProperty(example = "1.234", required = true, value = "")
 
   public Float getFloatItem() {
@@ -133,6 +140,7 @@ public class TypeHolderExample {
    * Get integerItem
    * @return integerItem
   **/
+  @NotNull
   @ApiModelProperty(example = "-2", required = true, value = "")
 
   public Integer getIntegerItem() {
@@ -155,6 +163,7 @@ public class TypeHolderExample {
    * Get boolItem
    * @return boolItem
   **/
+  @NotNull
   @ApiModelProperty(example = "true", required = true, value = "")
 
   public Boolean isBoolItem() {
@@ -182,6 +191,7 @@ public class TypeHolderExample {
    * Get arrayItem
    * @return arrayItem
   **/
+  @NotNull
   @ApiModelProperty(example = "[0, 1, 2, 3]", required = true, value = "")
 
   public List<Integer> getArrayItem() {
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/User.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/User.java
index d9111531781..760ff305379 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/User.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/User.java
@@ -23,6 +23,9 @@ import com.google.gson.stream.JsonWriter;
 import io.swagger.annotations.ApiModel;
 import io.swagger.annotations.ApiModelProperty;
 import java.io.IOException;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * User
diff --git a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
index 44f00ecc1bd..d1bae238ba5 100644
--- a/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
+++ b/samples/client/petstore/java/rest-assured/src/main/java/org/openapitools/client/model/XmlItem.java
@@ -26,6 +26,9 @@ import java.io.IOException;
 import java.math.BigDecimal;
 import java.util.ArrayList;
 import java.util.List;
+import javax.validation.constraints.*;
+import javax.validation.Valid;
+import org.hibernate.validator.constraints.*;
 
 /**
  * XmlItem
@@ -183,6 +186,7 @@ public class XmlItem {
    * @return attributeNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(example = "1.234", value = "")
 
   public BigDecimal getAttributeNumber() {
@@ -306,6 +310,7 @@ public class XmlItem {
    * @return nameNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(example = "1.234", value = "")
 
   public BigDecimal getNameNumber() {
@@ -460,6 +465,7 @@ public class XmlItem {
    * @return prefixNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(example = "1.234", value = "")
 
   public BigDecimal getPrefixNumber() {
@@ -614,6 +620,7 @@ public class XmlItem {
    * @return namespaceNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(example = "1.234", value = "")
 
   public BigDecimal getNamespaceNumber() {
@@ -768,6 +775,7 @@ public class XmlItem {
    * @return prefixNsNumber
   **/
   @javax.annotation.Nullable
+  @Valid
   @ApiModelProperty(example = "1.234", value = "")
 
   public BigDecimal getPrefixNsNumber() {