Android异步请求

 class MyTask_SendMessage extends AsyncTask<String, Void, String> {

         @Override
         protected void onPostExecute(String result) {
             super.onPostExecute(result);
             ShowResponseFromTuling(result);
         }

         @Override
         protected String doInBackground(String... arg0) {
             HttpPost request = new HttpPost(arg0[0]);
             // 必须要添加该Http头才能调用WebMethod时返回JSON数据
             request.addHeader("Content-Type", "application/json; charset=utf-8");

             try {
                 // 添加参数
                 JSONObject param = new JSONObject();
                 param.put("key", Constants.API_KEY);
                 param.put("info", arg0[1]);
                 HttpEntity entity = new StringEntity(param.toString(), "utf-8");
                 request.setEntity(entity);

                 // 发送请求并获取反馈
                 HttpResponse response = new DefaultHttpClient()
                         .execute(request);
                 int code = response.getStatusLine().getStatusCode();
                 if (code == 200) {
                     String result = EntityUtils.toString(response.getEntity());
                     return result.toString();
                 }
                 return "";
             } catch (Exception e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
             return "";
         }

     }