don't create a new response object, and keep the old string value in the exception and have the object as ApiException->responseObject

modules/swagger-codegen/src/main/resources/php/ApiException.mustache

@@ -24,17 +24,22 @@ class ApiException extends Exception {
   /**
    * The HTTP body of the server response.
    */
-  protected $response_body;
+  protected $responseBody;
 
   /**
    * The HTTP header of the server response.
    */
-  protected $response_headers;
+  protected $responseHeaders;
+
+  /**
+   * The deserialized response object
+   */
+  protected $responseObject;
 
   public function __construct($message="", $code=0, $responseHeaders=null, $responseBody=null) {
     parent::__construct($message, $code);
-    $this->response_headers = $responseHeaders;
-    $this->response_body = $responseBody;
+    $this->responseHeaders = $responseHeaders;
+    $this->responseBody = $responseBody;
   }
 
   /**
@@ -43,7 +48,7 @@ class ApiException extends Exception {
    * @return string HTTP response header
    */
   public function getResponseHeaders() {
-    return $this->response_headers;
+    return $this->responseHeaders;
   }
 
   /**
@@ -52,7 +57,18 @@ class ApiException extends Exception {
    * @return string HTTP response body
    */
   public function getResponseBody() {
-    return $this->response_body;
+    return $this->responseBody;
   }
 
+  /**
+   * sets the deseralized response object (during deserialization)
+   * @param mixed $obj
+   */
+  public function setResponseObject($obj) {
+    $this->responseObject = $obj;
+  }
+
+  public function getResponseObject() {
+    return $this->responseObject;
+  }
 }

modules/swagger-codegen/src/main/resources/php/api.mustache

@@ -140,16 +140,14 @@ class {{classname}} {
                                               $queryParams, $httpBody,
                                               $headerParams);
       } catch (ApiException $e) {
-        $throw = $e;
-
         switch ($e->getCode()) { {{#responses}}{{#dataType}}
           case {{code}}:
             $data = ObjectSerializer::deserialize($e->getResponseBody(), '{{dataType}}');
-            $throw = new ApiException("{{message}}", $e->getCode(), $e->getResponseHeaders(), $data);
+            $e->setResponseObject($data);
             break;{{/dataType}}{{/responses}}
         }
 
-        throw $throw;
+        throw $e;
       }
       {{#returnType}}
       if (!$response) {