diff --git a/README.md b/README.md
index 6fe067b7342..c951c4b9620 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ The Swagger Specification has undergone 3 revisions since initial creation in 20
 
 Swagger Codegen Version | Release Date | Swagger Spec compatibility | Notes
 ----------------------- | ------------ | -------------------------- | -----
-1.5.0-M2                | 2015-04-06   | 1.0, 1.1, 1.2, 2.0   | [master](https://github.com/swagger-api/swagger-codegen)
+2.1.0-M2                | 2015-04-06   | 1.0, 1.1, 1.2, 2.0   | [master](https://github.com/swagger-api/swagger-codegen)
 2.0.17                  | 2014-08-22   | 1.1, 1.2      | [tag v2.0.17](https://github.com/swagger-api/swagger-codegen/tree/v2.0.17)
 1.0.4                   | 2012-04-12   | 1.0, 1.1      | [tag v1.0.4](https://github.com/swagger-api/swagger-codegen/tree/swagger-codegen_2.9.1-1.1)
 
diff --git a/modules/swagger-codegen-cli/pom.xml b/modules/swagger-codegen-cli/pom.xml
index caf6d3d54a3..d5c54882f5d 100644
--- a/modules/swagger-codegen-cli/pom.xml
+++ b/modules/swagger-codegen-cli/pom.xml
@@ -3,7 +3,7 @@
     <parent>
         <groupId>com.wordnik</groupId>
         <artifactId>swagger-codegen-project</artifactId>
-        <version>1.5.0-M2</version>
+        <version>2.1.0-M2</version>
         <relativePath>../..</relativePath>
     </parent>
     <modelVersion>4.0.0</modelVersion>
diff --git a/modules/swagger-codegen/pom.xml b/modules/swagger-codegen/pom.xml
index 54c8cf9f6cb..e4b70a492b8 100644
--- a/modules/swagger-codegen/pom.xml
+++ b/modules/swagger-codegen/pom.xml
@@ -2,7 +2,7 @@
   <parent>
     <groupId>com.wordnik</groupId>
     <artifactId>swagger-codegen-project</artifactId>
-    <version>1.5.0-M2</version>
+    <version>2.1.0-M2</version>
     <relativePath>../..</relativePath>
   </parent>
   <modelVersion>4.0.0</modelVersion>
@@ -10,7 +10,7 @@
   <artifactId>swagger-codegen</artifactId>
   <packaging>jar</packaging>
   <name>swagger-codegen (core library)</name>
-  <version>1.5.0-M2</version>
+  <version>2.1.0-M2</version>
   <build>
     <sourceDirectory>src/main/java</sourceDirectory>
     <defaultGoal>install</defaultGoal>
diff --git a/modules/swagger-codegen/src/main/resources/Java/apiInvoker.mustache b/modules/swagger-codegen/src/main/resources/Java/apiInvoker.mustache
index ac689046047..c30ba4cdd12 100644
--- a/modules/swagger-codegen/src/main/resources/Java/apiInvoker.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/apiInvoker.mustache
@@ -18,6 +18,7 @@ import javax.ws.rs.core.MediaType;
 
 import java.util.Collection;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Date;
@@ -195,47 +196,42 @@ public class ApiInvoker {
       response = (ClientResponse) builder.get(ClientResponse.class);
     }
     else if ("POST".equals(method)) {
-      if(body == null)
+      if (contentType.startsWith("application/x-www-form-urlencoded")) {
+        String encodedFormParams = this
+            .getXWWWFormUrlencodedParams(formParams);
+        response = builder.type(contentType).post(ClientResponse.class,
+            encodedFormParams);
+      } else if (body == null) {
         response = builder.post(ClientResponse.class, null);
-      else if(body instanceof FormDataMultiPart) {
+      } else if(body instanceof FormDataMultiPart) {
         response = builder.type(contentType).post(ClientResponse.class, body);
       }
       else
         response = builder.type(contentType).post(ClientResponse.class, serialize(body));
     }
     else if ("PUT".equals(method)) {
-      if(body == null)
+      if ("application/x-www-form-urlencoded".equals(contentType)) {
+          String encodedFormParams = this
+              .getXWWWFormUrlencodedParams(formParams);
+          response = builder.type(contentType).put(ClientResponse.class,
+              encodedFormParams);
+      } else if(body == null) {
         response = builder.put(ClientResponse.class, serialize(body));
-      else {
-        if("application/x-www-form-urlencoded".equals(contentType)) {
-          StringBuilder formParamBuilder = new StringBuilder();
-
-          // encode the form params
-          for(String key : formParams.keySet()) {
-            String value = formParams.get(key);
-            if(value != null && !"".equals(value.trim())) {
-              if(formParamBuilder.length() > 0) {
-                formParamBuilder.append("&");
-              }
-              try {
-                formParamBuilder.append(URLEncoder.encode(key, "utf8")).append("=").append(URLEncoder.encode(value, "utf8"));
-              }
-              catch (Exception e) {
-                // move on to next
-              }
-            }
-          }
-          response = builder.type(contentType).put(ClientResponse.class, formParamBuilder.toString());
-        }
-        else
+      } else {
           response = builder.type(contentType).put(ClientResponse.class, serialize(body));
       }
     }
     else if ("DELETE".equals(method)) {
-      if(body == null)
+      if ("application/x-www-form-urlencoded".equals(contentType)) {
+        String encodedFormParams = this
+            .getXWWWFormUrlencodedParams(formParams);
+        response = builder.type(contentType).delete(ClientResponse.class,
+            encodedFormParams);
+      } else if(body == null) {
         response = builder.delete(ClientResponse.class);
-      else
+      } else {
         response = builder.type(contentType).delete(ClientResponse.class, serialize(body));
+      }
     }
     else {
       throw new ApiException(500, "unknown method type " + method);
@@ -267,6 +263,31 @@ public class ApiInvoker {
     }
   }
 
+  private String getXWWWFormUrlencodedParams(Map<String, String> formParams) {
+    StringBuilder formParamBuilder = new StringBuilder();
+
+    for (Entry<String, String> param : formParams.entrySet()) {
+      String keyStr = ApiInvoker.parameterToString(param.getKey());
+      String valueStr = ApiInvoker.parameterToString(param.getValue());
+
+      try {
+        formParamBuilder.append(URLEncoder.encode(keyStr, "utf8"))
+            .append("=")
+            .append(URLEncoder.encode(valueStr, "utf8"));
+        formParamBuilder.append("&");
+      } catch (UnsupportedEncodingException e) {
+        // move on to next
+      }
+    }
+    String encodedFormParams = formParamBuilder.toString();
+    if (encodedFormParams.endsWith("&")) {
+      encodedFormParams = encodedFormParams.substring(0,
+          encodedFormParams.length() - 1);
+    }
+    return encodedFormParams;
+  }
+
+
   private Client getClient(String host) {
     if(!hostMap.containsKey(host)) {
       Client client = Client.create();
@@ -276,4 +297,4 @@ public class ApiInvoker {
     }
     return hostMap.get(host);
   }
-}
+}
\ No newline at end of file
diff --git a/modules/swagger-codegen/src/main/resources/JavaJaxRS/pom.mustache b/modules/swagger-codegen/src/main/resources/JavaJaxRS/pom.mustache
index aa7ecf5ab48..607f2116f54 100644
--- a/modules/swagger-codegen/src/main/resources/JavaJaxRS/pom.mustache
+++ b/modules/swagger-codegen/src/main/resources/JavaJaxRS/pom.mustache
@@ -129,7 +129,7 @@
     </repository>
   </repositories>
   <properties>
-    <swagger-core-version>1.5.0-M2</swagger-core-version>
+    <swagger-core-version>2.1.0-M2</swagger-core-version>
     <jetty-version>9.2.9.v20150224</jetty-version>
     <jersey-version>1.13</jersey-version>
     <slf4j-version>1.6.3</slf4j-version>
diff --git a/modules/swagger-generator/pom.xml b/modules/swagger-generator/pom.xml
index bf49f2b976f..582e40f59da 100644
--- a/modules/swagger-generator/pom.xml
+++ b/modules/swagger-generator/pom.xml
@@ -3,14 +3,14 @@
   <parent>
     <groupId>com.wordnik</groupId>
     <artifactId>swagger-codegen-project</artifactId>
-    <version>1.5.0-M2</version>
+    <version>2.1.0-M2</version>
     <relativePath>../..</relativePath>
   </parent>
   <groupId>com.wordnik</groupId>
   <artifactId>swagger-generator</artifactId>
   <packaging>war</packaging>
   <name>swagger-generator</name>
-  <version>1.5.0-M2</version>
+  <version>2.1.0-M2</version>
   <build>
     <sourceDirectory>src/main/java</sourceDirectory>
     <plugins>
diff --git a/pom.xml b/pom.xml
index 59bf41ff0d7..1f386e48b76 100644
--- a/pom.xml
+++ b/pom.xml
@@ -9,7 +9,7 @@
   <artifactId>swagger-codegen-project</artifactId>
   <packaging>pom</packaging>
   <name>swagger-codegen-project</name>
-  <version>1.5.0-M2</version>
+  <version>2.1.0-M2</version>
   <url>https://github.com/swagger-api/swagger-codegen</url>
   <scm>
     <connection>scm:git:git@github.com:swagger-api/swagger-codegen.git</connection>
diff --git a/samples/client/petstore/android-java/src/main/java/io/swagger/client/ApiInvoker.java b/samples/client/petstore/android-java/src/main/java/io/swagger/client/ApiInvoker.java
index 8c3f271a13e..dec0db43f66 100644
--- a/samples/client/petstore/android-java/src/main/java/io/swagger/client/ApiInvoker.java
+++ b/samples/client/petstore/android-java/src/main/java/io/swagger/client/ApiInvoker.java
@@ -16,6 +16,7 @@
 import org.apache.http.entity.StringEntity;
 import org.apache.http.impl.client.*;
 import org.apache.http.impl.conn.*;
+import org.apache.http.impl.conn.tsccm.*;
 import org.apache.http.params.*;
 import org.apache.http.util.EntityUtils;
 
@@ -381,7 +382,7 @@ public Socket createSocket() throws IOException {
       schemeRegistry.register(httpsScheme);
       schemeRegistry.register(new Scheme("http", PlainSocketFactory.getSocketFactory(), 80));
 
-      ignoreSSLConnectionManager = new SingleClientConnManager(new BasicHttpParams(), schemeRegistry);
+      ignoreSSLConnectionManager = new ThreadSafeClientConnManager(new BasicHttpParams(), schemeRegistry);
     } catch (NoSuchAlgorithmException e) {
       // This will only be thrown if SSL isn't available for some reason.
     } catch (KeyManagementException e) {
diff --git a/samples/client/petstore/php/SwaggerPetstore-php/lib/models/Category.php b/samples/client/petstore/php/SwaggerPetstore-php/lib/models/Category.php
index 2bd2410268c..101222b4503 100644
--- a/samples/client/petstore/php/SwaggerPetstore-php/lib/models/Category.php
+++ b/samples/client/petstore/php/SwaggerPetstore-php/lib/models/Category.php
@@ -16,7 +16,7 @@
  */
 
 /**
- * testing category description
+ * 
  *
  * NOTE: This class is auto generated by the swagger code generator program. Do not edit the class manually.
  *
diff --git a/samples/html/index.html b/samples/html/index.html
index 1055c9962ad..1ac869c1cee 100644
--- a/samples/html/index.html
+++ b/samples/html/index.html
@@ -420,7 +420,7 @@ <h3 class="field-label">Example data</h3>
     
     <h3 class="field-label">Example data</h3>
     <div class="example-data-content-type">Content-Type: application/xml</div>
-    <pre class="example"><code>not implemented com.wordnik.swagger.models.properties.MapProperty@2acca551</code></pre>
+    <pre class="example"><code>not implemented com.wordnik.swagger.models.properties.MapProperty@787b217</code></pre>
     
   </div> <!-- method -->
   <hr>
@@ -444,11 +444,11 @@ <h3 class="field-label">Return type</h3>
     
     <h3 class="field-label">Example data</h3>
     <div class="example-data-content-type">Content-Type: application/json</div>
-    <pre class="example"><code>{\n  "id" : 123456789,\n  "petId" : 123456789,\n  "complete" : true,\n  "status" : "aeiou",\n  "quantity" : 123,\n  "shipDate" : "2015-04-05T03:02:18.855+0000"\n}</code></pre>
+    <pre class="example"><code>{\n  "id" : 123456789,\n  "petId" : 123456789,\n  "complete" : true,\n  "status" : "aeiou",\n  "quantity" : 123,\n  "shipDate" : "2015-04-06T14:06:47.931+0000"\n}</code></pre>
     
     <h3 class="field-label">Example data</h3>
     <div class="example-data-content-type">Content-Type: application/xml</div>
-    <pre class="example"><code><Order>\n  <id>123456</id>\n  <petId>123456</petId>\n  <quantity>0</quantity>\n  <shipDate>2015-04-04T20:02:18.857Z</shipDate>\n  <status>string</status>\n  <complete>true</complete>\n</Order></code></pre>
+    <pre class="example"><code><Order>\n  <id>123456</id>\n  <petId>123456</petId>\n  <quantity>0</quantity>\n  <shipDate>2015-04-06T08:06:47.934Z</shipDate>\n  <status>string</status>\n  <complete>true</complete>\n</Order></code></pre>
     
   </div> <!-- method -->
   <hr>
@@ -472,11 +472,11 @@ <h3 class="field-label">Return type</h3>
     
     <h3 class="field-label">Example data</h3>
     <div class="example-data-content-type">Content-Type: application/json</div>
-    <pre class="example"><code>{\n  "id" : 123456789,\n  "petId" : 123456789,\n  "complete" : true,\n  "status" : "aeiou",\n  "quantity" : 123,\n  "shipDate" : "2015-04-05T03:02:18.859+0000"\n}</code></pre>
+    <pre class="example"><code>{\n  "id" : 123456789,\n  "petId" : 123456789,\n  "complete" : true,\n  "status" : "aeiou",\n  "quantity" : 123,\n  "shipDate" : "2015-04-06T14:06:47.935+0000"\n}</code></pre>
     
     <h3 class="field-label">Example data</h3>
     <div class="example-data-content-type">Content-Type: application/xml</div>
-    <pre class="example"><code><Order>\n  <id>123456</id>\n  <petId>123456</petId>\n  <quantity>0</quantity>\n  <shipDate>2015-04-04T20:02:18.859Z</shipDate>\n  <status>string</status>\n  <complete>true</complete>\n</Order></code></pre>
+    <pre class="example"><code><Order>\n  <id>123456</id>\n  <petId>123456</petId>\n  <quantity>0</quantity>\n  <shipDate>2015-04-06T08:06:47.935Z</shipDate>\n  <status>string</status>\n  <complete>true</complete>\n</Order></code></pre>
     
   </div> <!-- method -->
   <hr>
diff --git a/samples/server/petstore/jaxrs/pom.xml b/samples/server/petstore/jaxrs/pom.xml
index 05764d01c0d..d75c6bbfda8 100644
--- a/samples/server/petstore/jaxrs/pom.xml
+++ b/samples/server/petstore/jaxrs/pom.xml
@@ -129,7 +129,7 @@
     </repository>
   </repositories>
   <properties>
-    <swagger-core-version>1.5.0-M2</swagger-core-version>
+    <swagger-core-version>2.1.0-M2</swagger-core-version>
     <jetty-version>9.2.9.v20150224</jetty-version>
     <jersey-version>1.13</jersey-version>
     <slf4j-version>1.6.3</slf4j-version>