diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
index 4fe5da20b19..1422b1c36a0 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultCodegen.java
@@ -534,6 +534,7 @@ public class DefaultCodegen {
         if (model instanceof ArrayModel) {
             ArrayModel am = (ArrayModel) model;
             ArrayProperty arrayProperty = new ArrayProperty(am.getItems());
+            m.hasEnums = false; // Otherwise there will be a NullPointerException in JavaClientCodegen.fromModel
             addParentContainer(m, name, arrayProperty);
         } else if (model instanceof RefModel) {
             // TODO
diff --git a/modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache b/modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache
index 2846c409c60..1a0dc5bc3a7 100644
--- a/modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/ApiClient.mustache
@@ -373,7 +373,7 @@ public class ApiClient {
     }
   }
 
-  private ClientResponse getAPIResponse(String path, String method, List<Pair> queryParams, Object body, byte[] binaryBody, Map<String, String> headerParams, Map<String, String> formParams, String accept, String contentType, String[] authNames) throws ApiException {
+  private ClientResponse getAPIResponse(String path, String method, List<Pair> queryParams, Object body, byte[] binaryBody, Map<String, String> headerParams, Map<String, Object> formParams, String accept, String contentType, String[] authNames) throws ApiException {
 
     if (body != null && binaryBody != null){
       throw new ApiException(500, "either body or binaryBody must be null");
@@ -490,7 +490,7 @@ public class ApiClient {
    * @param authNames The authentications to apply
    * @return The response body in type of string
    */
-   public <T> T invokeAPI(String path, String method, List<Pair> queryParams, Object body, byte[] binaryBody, Map<String, String> headerParams, Map<String, String> formParams, String accept, String contentType, String[] authNames) throws ApiException {
+   public <T> T invokeAPI(String path, String method, List<Pair> queryParams, Object body, byte[] binaryBody, Map<String, String> headerParams, Map<String, Object> formParams, String accept, String contentType, String[] authNames, TypeRef returnType) throws ApiException {
 
     ClientResponse response = getAPIResponse(path, method, queryParams, body, binaryBody, headerParams, formParams, accept, contentType, authNames);
 
@@ -534,7 +534,7 @@ public class ApiClient {
    * @param authNames The authentications to apply
    * @return The response body in type of string
    */
- public byte[] invokeBinaryAPI(String path, String method, List<Pair> queryParams, Object body, byte[] binaryBody, Map<String, String> headerParams, Map<String, String> formParams, String accept, String contentType, String[]authNames) throws ApiException {
+ public byte[] invokeBinaryAPI(String path, String method, List<Pair> queryParams, Object body, byte[] binaryBody, Map<String, String> headerParams, Map<String, Object> formParams, String accept, String contentType, String[]authNames) throws ApiException {
 
     ClientResponse response = getAPIResponse(path, method, queryParams, body, binaryBody, headerParams, formParams, accept, contentType, authNames);
 
diff --git a/modules/swagger-codegen/src/main/resources/Java/api.mustache b/modules/swagger-codegen/src/main/resources/Java/api.mustache
index 7d6ccc4c6c5..53aa42ec37c 100644
--- a/modules/swagger-codegen/src/main/resources/Java/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/api.mustache
@@ -98,9 +98,9 @@ public class {{classname}} {
     {{^isBinary}}
     {{#returnType}}
     TypeRef {{localVariablePrefix}}returnType = new TypeRef<{{{returnType}}}>() {};
-    return {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}path, "{{httpMethod}}", {{localVariablePrefix}}queryParams, {{localVariablePrefix}}postBody, {{localVariablePrefix}}headerParams, {{localVariablePrefix}}formParams, {{localVariablePrefix}}accept, {{localVariablePrefix}}contentType, {{localVariablePrefix}}authNames, {{localVariablePrefix}}returnType);
+    return {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}path, "{{httpMethod}}", {{localVariablePrefix}}queryParams, {{localVariablePrefix}}postBody, {{localVariablePrefix}}postBinaryBody, {{localVariablePrefix}}headerParams, {{localVariablePrefix}}formParams, {{localVariablePrefix}}accept, {{localVariablePrefix}}contentType, {{localVariablePrefix}}authNames, {{localVariablePrefix}}returnType);
     {{/returnType}}{{^returnType}}
-    {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}path, "{{httpMethod}}", {{localVariablePrefix}}queryParams, {{localVariablePrefix}}postBody, {{localVariablePrefix}}headerParams, {{localVariablePrefix}}formParams, {{localVariablePrefix}}accept, {{localVariablePrefix}}contentType, {{localVariablePrefix}}authNames, null);
+    {{localVariablePrefix}}apiClient.invokeAPI({{localVariablePrefix}}path, "{{httpMethod}}", {{localVariablePrefix}}queryParams, {{localVariablePrefix}}postBody, {{localVariablePrefix}}postBinaryBody, {{localVariablePrefix}}headerParams, {{localVariablePrefix}}formParams, {{localVariablePrefix}}accept, {{localVariablePrefix}}contentType, {{localVariablePrefix}}authNames, null);
     {{/returnType}}
     {{/isBinary}}