diff --git a/bin/mysql-schema-petstore.sh b/bin/mysql-schema-petstore.sh
old mode 100644
new mode 100755
diff --git a/bin/springboot-virtualan-petstore-server.sh b/bin/springboot-virtualan-petstore-server.sh
old mode 100644
new mode 100755
diff --git a/bin/utils/ensure-up-to-date b/bin/utils/ensure-up-to-date
index 2411f06e42aa..19d9003d1a06 100755
--- a/bin/utils/ensure-up-to-date
+++ b/bin/utils/ensure-up-to-date
@@ -10,34 +10,43 @@ echo "Please press CTRL+C to stop or the script will continue in 5 seconds."
 sleep 5
 
 # LIST OF SCRIPTS:
-./bin/openapi3/ruby-client-petstore.sh > /dev/null 2>&1
-./bin/java-petstore-all.sh > /dev/null 2>&1
-./bin/java-jaxrs-petstore-server-all.sh > /dev/null 2>&1
-./bin/openapi3/jaxrs-jersey-petstore.sh > /dev/null 2>&1
-./bin/spring-all-pestore.sh > /dev/null 2>&1
-./bin/kotlin-client-petstore.sh > /dev/null 2>&1
-./bin/kotlin-client-string.sh > /dev/null 2>&1
-./bin/kotlin-client-threetenbp.sh > /dev/null 2>&1
-./bin/kotlin-server-petstore.sh > /dev/null 2>&1
-./bin/mysql-schema-petstore.sh > /dev/null 2>&1
-./bin/php-petstore.sh > /dev/null 2>&1
-./bin/php-silex-petstore-server.sh > /dev/null 2>&1
-./bin/php-symfony-petstore.sh > /dev/null 2>&1
-./bin/php-lumen-petstore-server.sh > /dev/null 2>&1
-./bin/php-slim-server-petstore.sh > /dev/null 2>&1
-./bin/php-ze-ph-petstore-server.sh > /dev/null 2>&1
-./bin/openapi3/php-petstore.sh > /dev/null 2>&1
-./bin/typescript-angular-petstore-all.sh > /dev/null 2>&1
-./bin/typescript-fetch-petstore-all.sh > /dev/null 2>&1
-./bin/typescript-node-petstore-all.sh > /dev/null 2>&1
-./bin/typescript-inversify-petstore.sh > /dev/null 2>&1
-./bin/rust-server-petstore.sh > /dev/null 2>&1
-./bin/haskell-http-client-petstore.sh > /dev/null 2>&1
-./bin/csharp-petstore.sh > /dev/null 2>&1
-./bin/meta-codegen.sh > /dev/null 2>&1
-./bin/utils/export_docs_generators.sh > /dev/null 2>&1
-./bin/go-petstore.sh > /dev/null 2>&1
-./bin/go-gin-petstore-server.sh > /dev/null 2>&1
+declare -a scripts=("./bin/openapi3/ruby-client-petstore.sh"
+"./bin/java-petstore-all.sh"
+"./bin/java-jaxrs-petstore-server-all.sh"
+"./bin/openapi3/jaxrs-jersey-petstore.sh"
+"./bin/spring-all-pestore.sh"
+"./bin/kotlin-client-petstore.sh"
+"./bin/kotlin-client-string.sh"
+"./bin/kotlin-client-threetenbp.sh"
+"./bin/kotlin-server-petstore.sh"
+"./bin/mysql-schema-petstore.sh"
+"./bin/php-petstore.sh"
+"./bin/php-silex-petstore-server.sh"
+"./bin/php-symfony-petstore.sh"
+"./bin/php-lumen-petstore-server.sh"
+"./bin/php-slim-server-petstore.sh"
+"./bin/php-ze-ph-petstore-server.sh"
+"./bin/openapi3/php-petstore.sh"
+"./bin/typescript-angular-petstore-all.sh"
+"./bin/typescript-fetch-petstore-all.sh"
+"./bin/typescript-node-petstore-all.sh"
+"./bin/typescript-inversify-petstore.sh"
+"./bin/rust-server-petstore.sh"
+"./bin/haskell-http-client-petstore.sh"
+"./bin/csharp-petstore.sh"
+"./bin/meta-codegen.sh"
+"./bin/utils/export_docs_generators.sh"
+"./bin/go-petstore.sh"
+"./bin/go-gin-petstore-server.sh")
+
+for script in "${scripts[@]}"; do
+  if eval $script > /dev/null 2>&1; then
+    echo "Executed $script successfully!"
+  else
+    echo "ERROR: Failed to run $script"
+    exit 1
+  fi
+done
 
 # Check:
 if [ -n "$(git status --porcelain)" ]; then
diff --git a/samples/schema/petstore/mysql/.openapi-generator/VERSION b/samples/schema/petstore/mysql/.openapi-generator/VERSION
index 6d94c9c2e12a..e24c1f857e01 100644
--- a/samples/schema/petstore/mysql/.openapi-generator/VERSION
+++ b/samples/schema/petstore/mysql/.openapi-generator/VERSION
@@ -1 +1 @@
-3.3.0-SNAPSHOT
\ No newline at end of file
+3.3.3-SNAPSHOT
\ No newline at end of file
diff --git a/samples/schema/petstore/mysql/mysql_schema.sql b/samples/schema/petstore/mysql/mysql_schema.sql
index 808ea185ea54..5870b90fab92 100644
--- a/samples/schema/petstore/mysql/mysql_schema.sql
+++ b/samples/schema/petstore/mysql/mysql_schema.sql
@@ -106,7 +106,7 @@ CREATE TABLE IF NOT EXISTS `Cat` (
 
 CREATE TABLE IF NOT EXISTS `Category` (
   `id` BIGINT DEFAULT NULL,
-  `name` TEXT DEFAULT NULL
+  `name` TEXT NOT NULL
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
 
 --
diff --git a/samples/server/petstore/springboot-virtualan/.openapi-generator/VERSION b/samples/server/petstore/springboot-virtualan/.openapi-generator/VERSION
index 6d94c9c2e12a..e24c1f857e01 100644
--- a/samples/server/petstore/springboot-virtualan/.openapi-generator/VERSION
+++ b/samples/server/petstore/springboot-virtualan/.openapi-generator/VERSION
@@ -1 +1 @@
-3.3.0-SNAPSHOT
\ No newline at end of file
+3.3.3-SNAPSHOT
\ No newline at end of file
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/AnotherFakeApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/AnotherFakeApi.java
index 7106b763d21c..2644b9cf934c 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/AnotherFakeApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/AnotherFakeApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.3-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/ApiUtil.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/ApiUtil.java
index a1b15b821fb1..896535c45958 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/ApiUtil.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/ApiUtil.java
@@ -8,8 +8,10 @@ import java.io.IOException;
 public class ApiUtil {
     public static void setExampleResponse(NativeWebRequest req, String contentType, String example) {
         try {
-            req.getNativeResponse(HttpServletResponse.class).addHeader("Content-Type", contentType);
-            req.getNativeResponse(HttpServletResponse.class).getOutputStream().print(example);
+            HttpServletResponse res = req.getNativeResponse(HttpServletResponse.class);
+            res.setCharacterEncoding("UTF-8");
+            res.addHeader("Content-Type", contentType);
+            res.getWriter().print(example);
         } catch (IOException e) {
             throw new RuntimeException(e);
         }
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeApi.java
index 0555f06748fa..e54182d3ae6e 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.3-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
@@ -55,14 +55,6 @@ public interface FakeApi {
         produces = { "*/*" }, 
         method = RequestMethod.POST)
     default ResponseEntity<Boolean> fakeOuterBooleanSerialize(@ApiParam(value = "Input boolean as post body"  )  @Valid @RequestBody Boolean body) {
-        getRequest().ifPresent(request -> {
-            for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
-                if (mediaType.isCompatibleWith(MediaType.valueOf("*/*"))) {
-                    ApiUtil.setExampleResponse(request, "*/*", "null");
-                    break;
-                }
-            }
-        });
         return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
 
     }
@@ -97,14 +89,6 @@ public interface FakeApi {
         produces = { "*/*" }, 
         method = RequestMethod.POST)
     default ResponseEntity<BigDecimal> fakeOuterNumberSerialize(@ApiParam(value = "Input number as post body"  )  @Valid @RequestBody BigDecimal body) {
-        getRequest().ifPresent(request -> {
-            for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
-                if (mediaType.isCompatibleWith(MediaType.valueOf("*/*"))) {
-                    ApiUtil.setExampleResponse(request, "*/*", "null");
-                    break;
-                }
-            }
-        });
         return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
 
     }
@@ -118,14 +102,6 @@ public interface FakeApi {
         produces = { "*/*" }, 
         method = RequestMethod.POST)
     default ResponseEntity<String> fakeOuterStringSerialize(@ApiParam(value = "Input string as post body"  )  @Valid @RequestBody String body) {
-        getRequest().ifPresent(request -> {
-            for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
-                if (mediaType.isCompatibleWith(MediaType.valueOf("*/*"))) {
-                    ApiUtil.setExampleResponse(request, "*/*", "null");
-                    break;
-                }
-            }
-        });
         return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
 
     }
@@ -189,7 +165,7 @@ public interface FakeApi {
     @RequestMapping(value = "/fake",
         consumes = { "application/x-www-form-urlencoded" },
         method = RequestMethod.POST)
-    default ResponseEntity<Void> testEndpointParameters(@ApiParam(value = "None", required=true, defaultValue="null") @RequestParam(value="number", required=true)  BigDecimal number,@ApiParam(value = "None", required=true, defaultValue="null") @RequestParam(value="double", required=true)  Double _double,@ApiParam(value = "None", required=true, defaultValue="null") @RequestParam(value="pattern_without_delimiter", required=true)  String patternWithoutDelimiter,@ApiParam(value = "None", required=true, defaultValue="null") @RequestParam(value="byte", required=true)  byte[] _byte,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="integer", required=false)  Integer integer,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="int32", required=false)  Integer int32,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="int64", required=false)  Long int64,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="float", required=false)  Float _float,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="string", required=false)  String string,@ApiParam(value = "file detail") @Valid @RequestPart("file") MultipartFile binary,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="date", required=false)  LocalDate date,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="dateTime", required=false)  OffsetDateTime dateTime,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="password", required=false)  String password,@ApiParam(value = "None", defaultValue="null") @RequestParam(value="callback", required=false)  String paramCallback) {
+    default ResponseEntity<Void> testEndpointParameters(@ApiParam(value = "None", required=true) @RequestParam(value="number", required=true)  BigDecimal number,@ApiParam(value = "None", required=true) @RequestParam(value="double", required=true)  Double _double,@ApiParam(value = "None", required=true) @RequestParam(value="pattern_without_delimiter", required=true)  String patternWithoutDelimiter,@ApiParam(value = "None", required=true) @RequestParam(value="byte", required=true)  byte[] _byte,@ApiParam(value = "None") @RequestParam(value="integer", required=false)  Integer integer,@ApiParam(value = "None") @RequestParam(value="int32", required=false)  Integer int32,@ApiParam(value = "None") @RequestParam(value="int64", required=false)  Long int64,@ApiParam(value = "None") @RequestParam(value="float", required=false)  Float _float,@ApiParam(value = "None") @RequestParam(value="string", required=false)  String string,@ApiParam(value = "file detail") @Valid @RequestPart("file") MultipartFile binary,@ApiParam(value = "None") @RequestParam(value="date", required=false)  LocalDate date,@ApiParam(value = "None") @RequestParam(value="dateTime", required=false)  OffsetDateTime dateTime,@ApiParam(value = "None") @RequestParam(value="password", required=false)  String password,@ApiParam(value = "None") @RequestParam(value="callback", required=false)  String paramCallback) {
         return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
 
     }
@@ -203,7 +179,19 @@ public interface FakeApi {
     @RequestMapping(value = "/fake",
         consumes = { "application/x-www-form-urlencoded" },
         method = RequestMethod.GET)
-    default ResponseEntity<Void> testEnumParameters(@ApiParam(value = "Header parameter enum test (string array)" , allowableValues=">, $") @RequestHeader(value="enum_header_string_array", required=false) List<String> enumHeaderStringArray,@ApiParam(value = "Header parameter enum test (string)" , allowableValues="_abc, -efg, (xyz)", defaultValue="-efg") @RequestHeader(value="enum_header_string", required=false) String enumHeaderString,@ApiParam(value = "Query parameter enum test (string array)", allowableValues = ">, $") @Valid @RequestParam(value = "enum_query_string_array", required = false) List<String> enumQueryStringArray,@ApiParam(value = "Query parameter enum test (string)", allowableValues = "_abc, -efg, (xyz)", defaultValue = "-efg") @Valid @RequestParam(value = "enum_query_string", required = false, defaultValue="-efg") String enumQueryString,@ApiParam(value = "Query parameter enum test (double)", allowableValues = "1, -2") @Valid @RequestParam(value = "enum_query_integer", required = false) Integer enumQueryInteger,@ApiParam(value = "Query parameter enum test (double)", allowableValues = "1.1, -1.2") @Valid @RequestParam(value = "enum_query_double", required = false) Double enumQueryDouble,@ApiParam(value = "Form parameter enum test (string array)", allowableValues=">, $", defaultValue="$") @RequestParam(value="enum_form_string_array", required=false)  List<String> enumFormStringArray,@ApiParam(value = "Form parameter enum test (string)", allowableValues="_abc, -efg, (xyz)", defaultValue="-efg") @RequestParam(value="enum_form_string", required=false)  String enumFormString) {
+    default ResponseEntity<Void> testEnumParameters(@ApiParam(value = "Header parameter enum test (string array)" , allowableValues=">, $", defaultValue="new ArrayList<>()") @RequestHeader(value="enum_header_string_array", required=false) List<String> enumHeaderStringArray,@ApiParam(value = "Header parameter enum test (string)" , allowableValues="_abc, -efg, (xyz)", defaultValue="-efg") @RequestHeader(value="enum_header_string", required=false) String enumHeaderString,@ApiParam(value = "Query parameter enum test (string array)", allowableValues = ">, $", defaultValue = "new ArrayList<>()") @Valid @RequestParam(value = "enum_query_string_array", required = false, defaultValue="new ArrayList<>()") List<String> enumQueryStringArray,@ApiParam(value = "Query parameter enum test (string)", allowableValues = "_abc, -efg, (xyz)", defaultValue = "-efg") @Valid @RequestParam(value = "enum_query_string", required = false, defaultValue="-efg") String enumQueryString,@ApiParam(value = "Query parameter enum test (double)", allowableValues = "1, -2") @Valid @RequestParam(value = "enum_query_integer", required = false) Integer enumQueryInteger,@ApiParam(value = "Query parameter enum test (double)", allowableValues = "1.1, -1.2") @Valid @RequestParam(value = "enum_query_double", required = false) Double enumQueryDouble,@ApiParam(value = "Form parameter enum test (string array)", allowableValues=">, $", defaultValue="$") @RequestParam(value="enum_form_string_array", required=false)  List<String> enumFormStringArray,@ApiParam(value = "Form parameter enum test (string)", allowableValues="_abc, -efg, (xyz)", defaultValue="-efg") @RequestParam(value="enum_form_string", required=false)  String enumFormString) {
+        return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
+
+    }
+
+
+    @ApiVirtual
+    @ApiOperation(value = "Fake endpoint to test group parameters (optional)", nickname = "testGroupParameters", notes = "Fake endpoint to test group parameters (optional)", tags={ "fake", })
+    @ApiResponses(value = { 
+        @ApiResponse(code = 400, message = "Someting wrong") })
+    @RequestMapping(value = "/fake",
+        method = RequestMethod.DELETE)
+    default ResponseEntity<Void> testGroupParameters(@ApiParam(value = "String in group parameters") @Valid @RequestParam(value = "string_group", required = false) Integer stringGroup,@ApiParam(value = "Boolean in group parameters" ) @RequestHeader(value="boolean_group", required=false) Boolean booleanGroup,@ApiParam(value = "Integer in group parameters") @Valid @RequestParam(value = "int64_group", required = false) Long int64Group) {
         return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
 
     }
@@ -229,7 +217,7 @@ public interface FakeApi {
     @RequestMapping(value = "/fake/jsonFormData",
         consumes = { "application/x-www-form-urlencoded" },
         method = RequestMethod.GET)
-    default ResponseEntity<Void> testJsonFormData(@ApiParam(value = "field1", required=true, defaultValue="null") @RequestParam(value="param", required=true)  String param,@ApiParam(value = "field2", required=true, defaultValue="null") @RequestParam(value="param2", required=true)  String param2) {
+    default ResponseEntity<Void> testJsonFormData(@ApiParam(value = "field1", required=true) @RequestParam(value="param", required=true)  String param,@ApiParam(value = "field2", required=true) @RequestParam(value="param2", required=true)  String param2) {
         return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
 
     }
@@ -248,7 +236,7 @@ public interface FakeApi {
         produces = { "application/json" }, 
         consumes = { "multipart/form-data" },
         method = RequestMethod.POST)
-    default ResponseEntity<ModelApiResponse> uploadFileWithRequiredFile(@ApiParam(value = "ID of pet to update",required=true) @PathVariable("petId") Long petId,@ApiParam(value = "file detail") @Valid @RequestPart("file") MultipartFile requiredFile,@ApiParam(value = "Additional data to pass to server", defaultValue="null") @RequestParam(value="additionalMetadata", required=false)  String additionalMetadata) {
+    default ResponseEntity<ModelApiResponse> uploadFileWithRequiredFile(@ApiParam(value = "ID of pet to update",required=true) @PathVariable("petId") Long petId,@ApiParam(value = "file detail") @Valid @RequestPart("file") MultipartFile requiredFile,@ApiParam(value = "Additional data to pass to server") @RequestParam(value="additionalMetadata", required=false)  String additionalMetadata) {
         getRequest().ifPresent(request -> {
             for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
                 if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeClassnameTestApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeClassnameTestApi.java
index d83dcb48787c..ef000d88f83f 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeClassnameTestApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeClassnameTestApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.3-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/PetApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/PetApi.java
index 21ad9cccb258..7dae1250ab2f 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/PetApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/PetApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.3-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
@@ -88,11 +88,11 @@ public interface PetApi {
     @RequestMapping(value = "/pet/findByStatus",
         produces = { "application/xml", "application/json" }, 
         method = RequestMethod.GET)
-    default ResponseEntity<List<Pet>> findPetsByStatus(@NotNull @ApiParam(value = "Status values that need to be considered for filter", required = true, allowableValues = "available, pending, sold") @Valid @RequestParam(value = "status", required = true) List<String> status) {
+    default ResponseEntity<List<Pet>> findPetsByStatus(@NotNull @ApiParam(value = "Status values that need to be considered for filter", required = true, allowableValues = "available, pending, sold", defaultValue = "new ArrayList<>()") @Valid @RequestParam(value = "status", required = true, defaultValue="new ArrayList<>()") List<String> status) {
         getRequest().ifPresent(request -> {
             for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
                 if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
-                    ApiUtil.setExampleResponse(request, "application/json", "{  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],  \"name\" : \"doggie\",  \"id\" : 0,  \"category\" : {    \"name\" : \"name\",    \"id\" : 6  },  \"tags\" : [ {    \"name\" : \"name\",    \"id\" : 1  }, {    \"name\" : \"name\",    \"id\" : 1  } ],  \"status\" : \"available\"}");
+                    ApiUtil.setExampleResponse(request, "application/json", "{  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],  \"name\" : \"doggie\",  \"id\" : 0,  \"category\" : {    \"name\" : \"default-name\",    \"id\" : 6  },  \"tags\" : [ {    \"name\" : \"name\",    \"id\" : 1  }, {    \"name\" : \"name\",    \"id\" : 1  } ],  \"status\" : \"available\"}");
                     break;
                 }
                 if (mediaType.isCompatibleWith(MediaType.valueOf("application/xml"))) {
@@ -119,11 +119,11 @@ public interface PetApi {
     @RequestMapping(value = "/pet/findByTags",
         produces = { "application/xml", "application/json" }, 
         method = RequestMethod.GET)
-    default ResponseEntity<List<Pet>> findPetsByTags(@NotNull @ApiParam(value = "Tags to filter by", required = true) @Valid @RequestParam(value = "tags", required = true) List<String> tags) {
+    default ResponseEntity<List<Pet>> findPetsByTags(@NotNull @ApiParam(value = "Tags to filter by", required = true, defaultValue = "new ArrayList<>()") @Valid @RequestParam(value = "tags", required = true, defaultValue="new ArrayList<>()") List<String> tags) {
         getRequest().ifPresent(request -> {
             for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
                 if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
-                    ApiUtil.setExampleResponse(request, "application/json", "{  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],  \"name\" : \"doggie\",  \"id\" : 0,  \"category\" : {    \"name\" : \"name\",    \"id\" : 6  },  \"tags\" : [ {    \"name\" : \"name\",    \"id\" : 1  }, {    \"name\" : \"name\",    \"id\" : 1  } ],  \"status\" : \"available\"}");
+                    ApiUtil.setExampleResponse(request, "application/json", "{  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],  \"name\" : \"doggie\",  \"id\" : 0,  \"category\" : {    \"name\" : \"default-name\",    \"id\" : 6  },  \"tags\" : [ {    \"name\" : \"name\",    \"id\" : 1  }, {    \"name\" : \"name\",    \"id\" : 1  } ],  \"status\" : \"available\"}");
                     break;
                 }
                 if (mediaType.isCompatibleWith(MediaType.valueOf("application/xml"))) {
@@ -152,7 +152,7 @@ public interface PetApi {
         getRequest().ifPresent(request -> {
             for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
                 if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
-                    ApiUtil.setExampleResponse(request, "application/json", "{  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],  \"name\" : \"doggie\",  \"id\" : 0,  \"category\" : {    \"name\" : \"name\",    \"id\" : 6  },  \"tags\" : [ {    \"name\" : \"name\",    \"id\" : 1  }, {    \"name\" : \"name\",    \"id\" : 1  } ],  \"status\" : \"available\"}");
+                    ApiUtil.setExampleResponse(request, "application/json", "{  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],  \"name\" : \"doggie\",  \"id\" : 0,  \"category\" : {    \"name\" : \"default-name\",    \"id\" : 6  },  \"tags\" : [ {    \"name\" : \"name\",    \"id\" : 1  }, {    \"name\" : \"name\",    \"id\" : 1  } ],  \"status\" : \"available\"}");
                     break;
                 }
                 if (mediaType.isCompatibleWith(MediaType.valueOf("application/xml"))) {
@@ -198,7 +198,7 @@ public interface PetApi {
     @RequestMapping(value = "/pet/{petId}",
         consumes = { "application/x-www-form-urlencoded" },
         method = RequestMethod.POST)
-    default ResponseEntity<Void> updatePetWithForm(@ApiParam(value = "ID of pet that needs to be updated",required=true) @PathVariable("petId") Long petId,@ApiParam(value = "Updated name of the pet", defaultValue="null") @RequestParam(value="name", required=false)  String name,@ApiParam(value = "Updated status of the pet", defaultValue="null") @RequestParam(value="status", required=false)  String status) {
+    default ResponseEntity<Void> updatePetWithForm(@ApiParam(value = "ID of pet that needs to be updated",required=true) @PathVariable("petId") Long petId,@ApiParam(value = "Updated name of the pet") @RequestParam(value="name", required=false)  String name,@ApiParam(value = "Updated status of the pet") @RequestParam(value="status", required=false)  String status) {
         return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
 
     }
@@ -217,7 +217,7 @@ public interface PetApi {
         produces = { "application/json" }, 
         consumes = { "multipart/form-data" },
         method = RequestMethod.POST)
-    default ResponseEntity<ModelApiResponse> uploadFile(@ApiParam(value = "ID of pet to update",required=true) @PathVariable("petId") Long petId,@ApiParam(value = "Additional data to pass to server", defaultValue="null") @RequestParam(value="additionalMetadata", required=false)  String additionalMetadata,@ApiParam(value = "file detail") @Valid @RequestPart("file") MultipartFile file) {
+    default ResponseEntity<ModelApiResponse> uploadFile(@ApiParam(value = "ID of pet to update",required=true) @PathVariable("petId") Long petId,@ApiParam(value = "Additional data to pass to server") @RequestParam(value="additionalMetadata", required=false)  String additionalMetadata,@ApiParam(value = "file detail") @Valid @RequestPart("file") MultipartFile file) {
         getRequest().ifPresent(request -> {
             for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
                 if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/StoreApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/StoreApi.java
index f4f013f0f554..ea993e412042 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/StoreApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/StoreApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.3-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/UserApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/UserApi.java
index 36d28a4b1f7a..cc6ca7852dc4 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/UserApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/UserApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.3.3-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Animal.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Animal.java
index 5c1ffdf53860..48d6137373d6 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Animal.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Animal.java
@@ -22,7 +22,7 @@ import javax.validation.constraints.*;
 
 public class Animal   {
   @JsonProperty("className")
-  private String className = null;
+  private String className;
 
   @JsonProperty("color")
   private String color = "red";
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Capitalization.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Capitalization.java
index 7071e42a5538..933f62ae3097 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Capitalization.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Capitalization.java
@@ -14,22 +14,22 @@ import javax.validation.constraints.*;
 
 public class Capitalization   {
   @JsonProperty("smallCamel")
-  private String smallCamel = null;
+  private String smallCamel;
 
   @JsonProperty("CapitalCamel")
-  private String capitalCamel = null;
+  private String capitalCamel;
 
   @JsonProperty("small_Snake")
-  private String smallSnake = null;
+  private String smallSnake;
 
   @JsonProperty("Capital_Snake")
-  private String capitalSnake = null;
+  private String capitalSnake;
 
   @JsonProperty("SCA_ETH_Flow_Points")
-  private String scAETHFlowPoints = null;
+  private String scAETHFlowPoints;
 
   @JsonProperty("ATT_NAME")
-  private String ATT_NAME = null;
+  private String ATT_NAME;
 
   public Capitalization smallCamel(String smallCamel) {
     this.smallCamel = smallCamel;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Cat.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Cat.java
index a1f38af43e0e..6238627830f7 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Cat.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Cat.java
@@ -15,7 +15,7 @@ import javax.validation.constraints.*;
 
 public class Cat extends Animal  {
   @JsonProperty("declawed")
-  private Boolean declawed = null;
+  private Boolean declawed;
 
   public Cat declawed(Boolean declawed) {
     this.declawed = declawed;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Category.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Category.java
index 5a43da49eeb5..e2ed2736e323 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Category.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Category.java
@@ -14,10 +14,10 @@ import javax.validation.constraints.*;
 
 public class Category   {
   @JsonProperty("id")
-  private Long id = null;
+  private Long id;
 
   @JsonProperty("name")
-  private String name = null;
+  private String name = "default-name";
 
   public Category id(Long id) {
     this.id = id;
@@ -48,7 +48,8 @@ public class Category   {
    * Get name
    * @return name
   **/
-  @ApiModelProperty(value = "")
+  @ApiModelProperty(required = true, value = "")
+  @NotNull
 
 
   public String getName() {
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ClassModel.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ClassModel.java
index 92b739c6db72..d505afe901a0 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ClassModel.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ClassModel.java
@@ -15,7 +15,7 @@ import javax.validation.constraints.*;
 
 public class ClassModel   {
   @JsonProperty("_class")
-  private String propertyClass = null;
+  private String propertyClass;
 
   public ClassModel propertyClass(String propertyClass) {
     this.propertyClass = propertyClass;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Client.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Client.java
index f689ff66b2dc..1a9ac3ac1084 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Client.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Client.java
@@ -14,7 +14,7 @@ import javax.validation.constraints.*;
 
 public class Client   {
   @JsonProperty("client")
-  private String client = null;
+  private String client;
 
   public Client client(String client) {
     this.client = client;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Dog.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Dog.java
index 7a5f1b21863e..76fc98d16499 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Dog.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Dog.java
@@ -15,7 +15,7 @@ import javax.validation.constraints.*;
 
 public class Dog extends Animal  {
   @JsonProperty("breed")
-  private String breed = null;
+  private String breed;
 
   public Dog breed(String breed) {
     this.breed = breed;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
index 7f37a350cf46..936cca2f316d 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumArrays.java
@@ -48,7 +48,7 @@ public class EnumArrays   {
   }
 
   @JsonProperty("just_symbol")
-  private JustSymbolEnum justSymbol = null;
+  private JustSymbolEnum justSymbol;
 
   /**
    * Gets or Sets arrayEnum
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumTest.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumTest.java
index 297d624ea58f..b7106dbe7eec 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumTest.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/EnumTest.java
@@ -49,7 +49,7 @@ public class EnumTest   {
   }
 
   @JsonProperty("enum_string")
-  private EnumStringEnum enumString = null;
+  private EnumStringEnum enumString;
 
   /**
    * Gets or Sets enumStringRequired
@@ -85,7 +85,7 @@ public class EnumTest   {
   }
 
   @JsonProperty("enum_string_required")
-  private EnumStringRequiredEnum enumStringRequired = null;
+  private EnumStringRequiredEnum enumStringRequired;
 
   /**
    * Gets or Sets enumInteger
@@ -119,7 +119,7 @@ public class EnumTest   {
   }
 
   @JsonProperty("enum_integer")
-  private EnumIntegerEnum enumInteger = null;
+  private EnumIntegerEnum enumInteger;
 
   /**
    * Gets or Sets enumNumber
@@ -153,7 +153,7 @@ public class EnumTest   {
   }
 
   @JsonProperty("enum_number")
-  private EnumNumberEnum enumNumber = null;
+  private EnumNumberEnum enumNumber;
 
   @JsonProperty("outerEnum")
   private OuterEnum outerEnum = null;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FormatTest.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FormatTest.java
index de4116286654..2c9ffcd8e11f 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FormatTest.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/FormatTest.java
@@ -19,43 +19,43 @@ import javax.validation.constraints.*;
 
 public class FormatTest   {
   @JsonProperty("integer")
-  private Integer integer = null;
+  private Integer integer;
 
   @JsonProperty("int32")
-  private Integer int32 = null;
+  private Integer int32;
 
   @JsonProperty("int64")
-  private Long int64 = null;
+  private Long int64;
 
   @JsonProperty("number")
-  private BigDecimal number = null;
+  private BigDecimal number;
 
   @JsonProperty("float")
-  private Float _float = null;
+  private Float _float;
 
   @JsonProperty("double")
-  private Double _double = null;
+  private Double _double;
 
   @JsonProperty("string")
-  private String string = null;
+  private String string;
 
   @JsonProperty("byte")
-  private byte[] _byte = null;
+  private byte[] _byte;
 
   @JsonProperty("binary")
-  private Resource binary = null;
+  private Resource binary;
 
   @JsonProperty("date")
-  private LocalDate date = null;
+  private LocalDate date;
 
   @JsonProperty("dateTime")
-  private OffsetDateTime dateTime = null;
+  private OffsetDateTime dateTime;
 
   @JsonProperty("uuid")
-  private UUID uuid = null;
+  private UUID uuid;
 
   @JsonProperty("password")
-  private String password = null;
+  private String password;
 
   public FormatTest integer(Integer integer) {
     this.integer = integer;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/HasOnlyReadOnly.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/HasOnlyReadOnly.java
index 45cc65677cb7..f65261e17843 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/HasOnlyReadOnly.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/HasOnlyReadOnly.java
@@ -14,10 +14,10 @@ import javax.validation.constraints.*;
 
 public class HasOnlyReadOnly   {
   @JsonProperty("bar")
-  private String bar = null;
+  private String bar;
 
   @JsonProperty("foo")
-  private String foo = null;
+  private String foo;
 
   public HasOnlyReadOnly bar(String bar) {
     this.bar = bar;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MapTest.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MapTest.java
index 14296751f1ec..4074efe672cf 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MapTest.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MapTest.java
@@ -9,7 +9,6 @@ import io.swagger.annotations.ApiModelProperty;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.openapitools.virtualan.model.StringBooleanMap;
 import javax.validation.Valid;
 import javax.validation.constraints.*;
 
@@ -62,7 +61,8 @@ public class MapTest   {
   private Map<String, Boolean> directMap = null;
 
   @JsonProperty("indirect_map")
-  private StringBooleanMap indirectMap = null;
+  @Valid
+  private Map<String, Boolean> indirectMap = null;
 
   public MapTest mapMapOfString(Map<String, Map<String, String>> mapMapOfString) {
     this.mapMapOfString = mapMapOfString;
@@ -149,24 +149,31 @@ public class MapTest   {
     this.directMap = directMap;
   }
 
-  public MapTest indirectMap(StringBooleanMap indirectMap) {
+  public MapTest indirectMap(Map<String, Boolean> indirectMap) {
     this.indirectMap = indirectMap;
     return this;
   }
 
+  public MapTest putIndirectMapItem(String key, Boolean indirectMapItem) {
+    if (this.indirectMap == null) {
+      this.indirectMap = new HashMap<>();
+    }
+    this.indirectMap.put(key, indirectMapItem);
+    return this;
+  }
+
   /**
    * Get indirectMap
    * @return indirectMap
   **/
   @ApiModelProperty(value = "")
 
-  @Valid
 
-  public StringBooleanMap getIndirectMap() {
+  public Map<String, Boolean> getIndirectMap() {
     return indirectMap;
   }
 
-  public void setIndirectMap(StringBooleanMap indirectMap) {
+  public void setIndirectMap(Map<String, Boolean> indirectMap) {
     this.indirectMap = indirectMap;
   }
 
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MixedPropertiesAndAdditionalPropertiesClass.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MixedPropertiesAndAdditionalPropertiesClass.java
index 8a55f4585d2e..c957f089ebed 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MixedPropertiesAndAdditionalPropertiesClass.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/MixedPropertiesAndAdditionalPropertiesClass.java
@@ -20,10 +20,10 @@ import javax.validation.constraints.*;
 
 public class MixedPropertiesAndAdditionalPropertiesClass   {
   @JsonProperty("uuid")
-  private UUID uuid = null;
+  private UUID uuid;
 
   @JsonProperty("dateTime")
-  private OffsetDateTime dateTime = null;
+  private OffsetDateTime dateTime;
 
   @JsonProperty("map")
   @Valid
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Model200Response.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Model200Response.java
index 27598e365680..c9a884636685 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Model200Response.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Model200Response.java
@@ -15,10 +15,10 @@ import javax.validation.constraints.*;
 
 public class Model200Response   {
   @JsonProperty("name")
-  private Integer name = null;
+  private Integer name;
 
   @JsonProperty("class")
-  private String propertyClass = null;
+  private String propertyClass;
 
   public Model200Response name(Integer name) {
     this.name = name;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelApiResponse.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelApiResponse.java
index 2966dd989066..675fd9e8b6c0 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelApiResponse.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelApiResponse.java
@@ -14,13 +14,13 @@ import javax.validation.constraints.*;
 
 public class ModelApiResponse   {
   @JsonProperty("code")
-  private Integer code = null;
+  private Integer code;
 
   @JsonProperty("type")
-  private String type = null;
+  private String type;
 
   @JsonProperty("message")
-  private String message = null;
+  private String message;
 
   public ModelApiResponse code(Integer code) {
     this.code = code;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelReturn.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelReturn.java
index ca8e032976d7..531ce74c8876 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelReturn.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ModelReturn.java
@@ -15,7 +15,7 @@ import javax.validation.constraints.*;
 
 public class ModelReturn   {
   @JsonProperty("return")
-  private Integer _return = null;
+  private Integer _return;
 
   public ModelReturn _return(Integer _return) {
     this._return = _return;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Name.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Name.java
index 13c0933b1bef..599ef80dd8e2 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Name.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Name.java
@@ -15,16 +15,16 @@ import javax.validation.constraints.*;
 
 public class Name   {
   @JsonProperty("name")
-  private Integer name = null;
+  private Integer name;
 
   @JsonProperty("snake_case")
-  private Integer snakeCase = null;
+  private Integer snakeCase;
 
   @JsonProperty("property")
-  private String property = null;
+  private String property;
 
   @JsonProperty("123Number")
-  private Integer _123number = null;
+  private Integer _123number;
 
   public Name name(Integer name) {
     this.name = name;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NumberOnly.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NumberOnly.java
index 56a6e6eb908c..fcf22dd7ae47 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NumberOnly.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/NumberOnly.java
@@ -15,7 +15,7 @@ import javax.validation.constraints.*;
 
 public class NumberOnly   {
   @JsonProperty("JustNumber")
-  private BigDecimal justNumber = null;
+  private BigDecimal justNumber;
 
   public NumberOnly justNumber(BigDecimal justNumber) {
     this.justNumber = justNumber;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Order.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Order.java
index d424a8c4a9c2..17bae2659c4a 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Order.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Order.java
@@ -16,16 +16,16 @@ import javax.validation.constraints.*;
 
 public class Order   {
   @JsonProperty("id")
-  private Long id = null;
+  private Long id;
 
   @JsonProperty("petId")
-  private Long petId = null;
+  private Long petId;
 
   @JsonProperty("quantity")
-  private Integer quantity = null;
+  private Integer quantity;
 
   @JsonProperty("shipDate")
-  private OffsetDateTime shipDate = null;
+  private OffsetDateTime shipDate;
 
   /**
    * Order Status
@@ -61,7 +61,7 @@ public class Order   {
   }
 
   @JsonProperty("status")
-  private StatusEnum status = null;
+  private StatusEnum status;
 
   @JsonProperty("complete")
   private Boolean complete = false;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/OuterComposite.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/OuterComposite.java
index 18fa81342254..52009e2e2dcb 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/OuterComposite.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/OuterComposite.java
@@ -15,13 +15,13 @@ import javax.validation.constraints.*;
 
 public class OuterComposite   {
   @JsonProperty("my_number")
-  private BigDecimal myNumber = null;
+  private BigDecimal myNumber;
 
   @JsonProperty("my_string")
-  private String myString = null;
+  private String myString;
 
   @JsonProperty("my_boolean")
-  private Boolean myBoolean = null;
+  private Boolean myBoolean;
 
   public OuterComposite myNumber(BigDecimal myNumber) {
     this.myNumber = myNumber;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
index beaa5cd32e38..2a0140aab2fd 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Pet.java
@@ -19,13 +19,13 @@ import javax.validation.constraints.*;
 
 public class Pet   {
   @JsonProperty("id")
-  private Long id = null;
+  private Long id;
 
   @JsonProperty("category")
   private Category category = null;
 
   @JsonProperty("name")
-  private String name = null;
+  private String name;
 
   @JsonProperty("photoUrls")
   @Valid
@@ -69,7 +69,7 @@ public class Pet   {
   }
 
   @JsonProperty("status")
-  private StatusEnum status = null;
+  private StatusEnum status;
 
   public Pet id(Long id) {
     this.id = id;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ReadOnlyFirst.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ReadOnlyFirst.java
index d0735af1ae32..54577965f9fb 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ReadOnlyFirst.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/ReadOnlyFirst.java
@@ -14,10 +14,10 @@ import javax.validation.constraints.*;
 
 public class ReadOnlyFirst   {
   @JsonProperty("bar")
-  private String bar = null;
+  private String bar;
 
   @JsonProperty("baz")
-  private String baz = null;
+  private String baz;
 
   public ReadOnlyFirst bar(String bar) {
     this.bar = bar;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/SpecialModelName.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/SpecialModelName.java
index baaaa7f81e3a..7586986c7976 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/SpecialModelName.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/SpecialModelName.java
@@ -14,7 +14,7 @@ import javax.validation.constraints.*;
 
 public class SpecialModelName   {
   @JsonProperty("$special[property.name]")
-  private Long $specialPropertyName = null;
+  private Long $specialPropertyName;
 
   public SpecialModelName $specialPropertyName(Long $specialPropertyName) {
     this.$specialPropertyName = $specialPropertyName;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Tag.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Tag.java
index 59c62dba8549..349a3d3c87a5 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Tag.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/Tag.java
@@ -14,10 +14,10 @@ import javax.validation.constraints.*;
 
 public class Tag   {
   @JsonProperty("id")
-  private Long id = null;
+  private Long id;
 
   @JsonProperty("name")
-  private String name = null;
+  private String name;
 
   public Tag id(Long id) {
     this.id = id;
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/User.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/User.java
index ab17265faa40..45664c9fabc0 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/User.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/model/User.java
@@ -14,28 +14,28 @@ import javax.validation.constraints.*;
 
 public class User   {
   @JsonProperty("id")
-  private Long id = null;
+  private Long id;
 
   @JsonProperty("username")
-  private String username = null;
+  private String username;
 
   @JsonProperty("firstName")
-  private String firstName = null;
+  private String firstName;
 
   @JsonProperty("lastName")
-  private String lastName = null;
+  private String lastName;
 
   @JsonProperty("email")
-  private String email = null;
+  private String email;
 
   @JsonProperty("password")
-  private String password = null;
+  private String password;
 
   @JsonProperty("phone")
-  private String phone = null;
+  private String phone;
 
   @JsonProperty("userStatus")
-  private Integer userStatus = null;
+  private Integer userStatus;
 
   public User id(Long id) {
     this.id = id;