diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/pom.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/pom.mustache
index 7f08e5afb58..cfe169c5eca 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/pom.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/okhttp-gson/pom.mustache
@@ -68,6 +68,7 @@
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>build-helper-maven-plugin</artifactId>
+        <version>1.10</version>
         <executions>
           <execution>
             <id>add_sources</id>
@@ -104,7 +105,7 @@
           <target>1.7</target>
         </configuration>
       </plugin>
-      <!-- For testing build.gradle -->
+      <!-- For testing build.gradle, build.sbt -->
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>exec-maven-plugin</artifactId>
@@ -123,9 +124,21 @@
               </arguments>
             </configuration>
           </execution>
+          <execution>
+            <id>sbt-test</id>
+            <phase>integration-test</phase>
+            <goals>
+              <goal>exec</goal>
+            </goals>
+            <configuration>
+              <executable>sbt</executable>
+              <arguments>
+                <argument>publishLocal</argument>
+              </arguments>
+            </configuration>
+          </execution>
         </executions>
       </plugin>
-
     </plugins>
   </build>
   <dependencies>
@@ -164,5 +177,6 @@
     <gson-version>2.6.2</gson-version>
     <maven-plugin-version>1.0.0</maven-plugin-version>
     <junit-version>4.12</junit-version>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>
 </project>
diff --git a/samples/client/petstore/java/okhttp-gson/pom.xml b/samples/client/petstore/java/okhttp-gson/pom.xml
index c3b5fe9ac46..638e1b9345e 100644
--- a/samples/client/petstore/java/okhttp-gson/pom.xml
+++ b/samples/client/petstore/java/okhttp-gson/pom.xml
@@ -68,6 +68,7 @@
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>build-helper-maven-plugin</artifactId>
+        <version>1.10</version>
         <executions>
           <execution>
             <id>add_sources</id>
@@ -104,7 +105,7 @@
           <target>1.7</target>
         </configuration>
       </plugin>
-      <!-- For testing build.gradle -->
+      <!-- For testing build.gradle, build.sbt -->
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>exec-maven-plugin</artifactId>
@@ -123,14 +124,6 @@
               </arguments>
             </configuration>
           </execution>
-        </executions>
-      </plugin>
-      <!-- For testing build.sbt -->
-      <plugin>
-        <groupId>org.codehaus.mojo</groupId>
-        <artifactId>exec-maven-plugin</artifactId>
-        <version>1.2.1</version>
-        <executions>
           <execution>
             <id>sbt-test</id>
             <phase>integration-test</phase>
@@ -146,7 +139,6 @@
           </execution>
         </executions>
       </plugin>
-
     </plugins>
   </build>
   <dependencies>
@@ -185,5 +177,6 @@
     <gson-version>2.6.2</gson-version>
     <maven-plugin-version>1.0.0</maven-plugin-version>
     <junit-version>4.12</junit-version>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>
 </project>
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiException.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiException.java
index 974c3becece..52f50890ee7 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiException.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/ApiException.java
@@ -3,7 +3,7 @@ package io.swagger.client;
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-05-31T22:17:12.179+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-06-02T16:59:44.170+08:00")
 public class ApiException extends Exception {
   private int code = 0;
   private Map<String, List<String>> responseHeaders = null;
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Configuration.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Configuration.java
index 46a1778050a..8bdc725b16b 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Configuration.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Configuration.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-05-31T22:17:12.179+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-06-02T16:59:44.170+08:00")
 public class Configuration {
   private static ApiClient defaultApiClient = new ApiClient();
 
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Pair.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Pair.java
index e3848de9f9e..78b5ef4b659 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Pair.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/Pair.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-05-31T22:17:12.179+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-06-02T16:59:44.170+08:00")
 public class Pair {
     private String name = "";
     private String value = "";
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
index fe552d7ae8d..73b7f76070c 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/StringUtil.java
@@ -1,6 +1,6 @@
 package io.swagger.client;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-05-31T22:17:12.179+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-06-02T16:59:44.170+08:00")
 public class StringUtil {
   /**
    * Check if the given array contains the given value (with case-insensitive comparison).
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/ApiKeyAuth.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/ApiKeyAuth.java
index 6b157ac6601..cb388174bfc 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/ApiKeyAuth.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/ApiKeyAuth.java
@@ -5,7 +5,7 @@ import io.swagger.client.Pair;
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-05-31T22:17:12.179+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-06-02T16:59:44.170+08:00")
 public class ApiKeyAuth implements Authentication {
   private final String location;
   private final String paramName;
diff --git a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/OAuth.java b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/OAuth.java
index c097462f5cd..ef8c42b0ea3 100644
--- a/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/OAuth.java
+++ b/samples/client/petstore/java/okhttp-gson/src/main/java/io/swagger/client/auth/OAuth.java
@@ -5,7 +5,7 @@ import io.swagger.client.Pair;
 import java.util.Map;
 import java.util.List;
 
-@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-05-31T22:17:12.179+08:00")
+@javax.annotation.Generated(value = "class io.swagger.codegen.languages.JavaClientCodegen", date = "2016-06-02T16:59:44.170+08:00")
 public class OAuth implements Authentication {
   private String accessToken;