             //拼接url
             components += self.queryComponents(key, value)
         }
-        return "&".join( components.map{"\($0)=\($1)"} as [String])
+       
+        return (components.map { "\($0)=\($1)" } as [String]).joinWithSeparator("&")
+
     }
     
     

                components += queryComponents("\(key)", value)
            }
        } else {
            components.extend([(escape(key), escape("\(value)"))])
        }
        
        return components

        }
    }
    func fireTask() {
        
        task = session.dataTaskWithRequest(request,completionHandler: { (data, response, error) -> Void in
            self.callback(data: NSString(data: data!, encoding: NSUTF8StringEncoding), response: response, error: error)
        })
        task.resume()
