安卓GET与POST网络请求的三种方式

http://image.baidu.com/search/index?tn=baiduimage&ipn=r&ct=201326592&cl=2&lm=-1&st=-1&fm=index&fr=&sf=1&fmq=&pv=&ic=0&nc=1&z=&se=1&showtab=0&fb=0&width=&height=&face=0&istype=2&ie=utf-8&word=%E5%8A%A8%E6%BC%AB，

  //1. URL
    URL url = new URL("http://image.baidu.com/search/index?tn=baiduimage&ipn=r&ct=201326592&cl=2&lm=-1&st=-1&fm=index&fr=&sf=1&fmq=&pv=&ic=0&nc=1&z=&se=1&showtab=0&fb=0&width=&height=&face=0&istype=2&ie=utf-8&word=%E5%8A%A8%E6%BC%AB");
    //2. HttpURLConnection
    HttpURLConnection conn=(HttpURLConnection)url.openConnection();
    //3. set(GET)
    conn.setRequestMethod("GET");
    //4. getInputStream
    InputStream is = conn.getInputStream();
    //5. 解析is，获取responseText，这里用缓冲字符流
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();
    String line = null;
    while((line=reader.readLine()) != null){
      sb.append(line);
    }
    //获取响应文本
    String responseText = sb.toString();

//1. URL
    URL url = new URL("http://image.baidu.com/search/index");
    //2. HttpURLConnection
    HttpURLConnection conn = (HttpURLConnection)url.openConnection();
    //3. POST
    conn.setRequestMethod("POST");
    //4. Content-Type,这里是固定写法，发送内容的类型
    conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
    //5. output，这里要记得开启输出流，将自己要添加的参数用这个输出流写进去，传给服务端，这是socket的基本结构
    conn.setDoOutput(true);
    OutputStream os = conn.getOutputStream();
    String param = "tn=baiduimage&ipn=r&ct=201326592&cl=2&lm=-1&st=-1&fm=index&fr=&sf=1&fmq=&pv=&ic=0&nc=1&z=&se=1&showtab=0&fb=0&width=&height=&face=0&istype=2&ie=utf-8&word=%E5%8A%A8%E6%BC%AB";
    //一定要记得将自己的参数转换为字节，编码格式是utf-8
    os.write(param.getBytes("utf-8"));
    os.flush();
    //6. is
    InputStream is = conn.getInputStream();
    //7. 解析is，获取responseText
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
    StringBuilder sb = new StringBuilder();
    String line = null;
    while((line=reader.readLine()) != null){
      sb.append(line);
    }
    //获取响应文本
    String responseText = sb.toString();

  //1. 创建RequestQueue,这是一个请求队列，相当于消息机制处理
  private RequestQueue  mQueue = Volley.newRequestQueue(this);
    //2. StringRequest
    String url = "http://www.baidu.com";
    StringRequest req = new StringRequest(url, 
        new Listener<String>() {
          //请求成功后回调 在主线程中执行
          public void onResponse(String responseText) {
            //解析json 封装结果数据
            Gson gson = new Gson();
            //这里用的Gson解析JSON字符串      
            User result=gson.fromJson(responseText,RequestResult.class);
                      }
        }, new ErrorListener() {
          //请求出错时 执行回调 在主线程中执行
          public void onErrorResponse(VolleyError error) {
            error.printStackTrace();
          }
        });
  //把req 添加到 请求队列中，一定要记得这一步，不然就相当于没有发送请求
    mQueue.add(req);

private RequestQueue mQueue; 
//post请求要用commonRequest请求实现
  String url="www.baidu.com";
  CommonRequest request = new CommonRequest(Request.Method.POST,url,new Response.Listener<String>() {
      public void onResponse(String response) {
        try {
        //这里是请求成功后调用的接口，用JSON工具解析数据
          JSONObject obj = new JSONObject(response);
        } catch (JSONException e) {
          e.printStackTrace();
        }
      }
    },new Response.ErrorListener() {
      public void onErrorResponse(VolleyError error) {
      }
    }){
      //如果用POST请求，要添加参数，一定要重写这个方法来添加参数
      @Override
      protected Map<String, String> getParams() throws AuthFailureError {
        Map<String, String> resultMap = new HashMap<String, String>();
        //这里的添加的具体参数   resultMap.put("username",user.getName());
        resultMap.put("userAge",user.getAge());
        resultMap.put("userGender",user.getGender());
resultMap.put("userSchool",user.getSchool());
        return resultMap;
      }
    };
    mQueue.add(request);
  }

//第一步，新建一个请求参数对象
RequestParams params=new RequestParams("www.baidu.com?inm=2");
//直接调用x.http().get()方法，这里注意x是要用全局MyApplication中初始化后才可以使用，初始化方法为x.Ext.init(this)
    x.http().get(params, new Callback.CommonCallback<String>() {
      @Override
      public void onCancelled(CancelledException arg0) {
      }
      @Override
      public void onError(Throwable arg0, boolean arg1) {
        Log.i("hap.zhu", "http_on_error,请求网络数据失败");
      }
      @Override
      public void onFinished() {
      }
      @Override
      public void onSuccess(String result) {
        Log.i("hap.zhu", "请求数据结果为:"+result);
        Gson gson=new Gson();
        Result result=gson.fromJson(result,Result.class);
        Log.i("hap.zhu", "加载结果为:"+result.toString());
    }
    });

//方法同GET，就是这么简单，网络请求成功会回调监听器里的success接口，直接处理数据结果就行
  RequestParams params=new RequestParams("www.baidu.com");
    params.addBodyParameter("email", username);
    params.addBodyParameter("password", password);
    x.http().post(params, new CommonCallback<String>() {
      @Override
      public void onCancelled(CancelledException arg0) {
      }
      @Override
      public void onError(Throwable arg0, boolean arg1) {
        //网络错误也会提示错误
        callback.Error(arg0.toString());
      }
      @Override
      public void onFinished() {
      }
      @Override
      public void onSuccess(String result) {
        Gson gson=new Gson();
      LoginResult loginResult=gson.fromJson(result, LoginResult.class);