content: package com.example.http;
  
  import android.os.Handler;
  import android.os.Message;
  
  public final class HttpHandler extends Handler {
      final public static int BODY_OK = 0;
      final public static int BODY_ERR = 1;
      private final MainActivity mainActivity;
  
      public HttpHandler(MainActivity mainActivity) {
          this.mainActivity = mainActivity;
      }
  
      @Override
      public void handleMessage(Message message) {
          switch (message.what) {
          case BODY_OK:
              mainActivity.onBody((String) message.obj);
              break;
          case BODY_ERR:
              mainActivity.onError((String) message.obj);
              break;
          default:
              break;
          }
      }
  
      /**
       * 成功获得 HTTP 数据体的回调方法
       * @param body {String} 响应的 HTTP 数据体
       */
      public void onBody(String body) {
          Message message = new Message();
          message.what = BODY_OK;
          message.obj  = body;
          this.sendMessage(message);
      }
  
      /**
       * 获取 HTTP 结果失败时的回调方法
       * @param domain {String} 请求的域名
       * @param url {String} 请求的 URL
       */
      public void onError(String domain, String url) {
          String error = "Domain: domain, " + "url: url";
          Message message = new Message();
          message.what = BODY_ERR;
          message.obj = error;
          this.sendMessage(message);
      }
  }
  