android通过httpClient请求获取JSON数据并且解析

使用.net创建一个ashx文件，并response.write  json格式

public void ProcessRequest(HttpContext context)



        {



            context.Response.ContentType = "text/plain";



            StringBuilder  jsonBuilder  = new StringBuilder();



            jsonBuilder.Append("{\"parent\":");



            jsonBuilder.Append("{\"children\":");



            jsonBuilder.Append("[");



            jsonBuilder.Append("{\"id\":\"11111\",\"title\":\"aaaaaaa\",\"name\":\"111111111aaaaaaaaaa\"},");



            jsonBuilder.Append("{\"id\":\"22222\",\"title\":\"bbbbbbb\",\"name\":\"222222222aaaaaaaaaa\"},");



            jsonBuilder.Append("{\"id\":\"33333\",\"title\":\"ccccccc\",\"name\":\"33333333aaaaaaaaaa\"}");



            jsonBuilder.Append("]}}");



 



            context.Response.Write(jsonBuilder.ToString());



        }

android代码

public class HttpClient_Get_Activity extends Activity {



   public TextView myTextView = null;



   @Override



   protected void onCreate(Bundle savedInstanceState) {



      // TODO Auto-generated method stub



      super.onCreate(savedInstanceState);



      this.setContentView(R.layout.httpget_httpclient_activity);



     



      Button btn = (Button)this.findViewById(R.id.button1);



      btn.setOnClickListener(new Button.OnClickListener(){



 



         @Override



         public void onClick(View v) {



              new ReadHttpGet().execute("http://190.160.10.79:7890/handler1.ashx");



         }



        



      });



   }



    class ReadHttpGet extends AsyncTask<Object, Object, Object>



    {



 



      @Override



      protected Object doInBackground(Object... params) {



         // TODO Auto-generated method stub



        



         HttpGet httpRequest = new HttpGet(params[0].toString());



         try



         {



            HttpClient httpClient = new DefaultHttpClient();



            HttpResponse httpResponse = httpClient.execute(httpRequest);



           



            if(httpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK)



            {



                String strResult = EntityUtils.toString(httpResponse.getEntity());



                return strResult;



            }



            else



            {



                return "请求出错";



            }



         }



         catch(ClientProtocolException e)



         {



           



         }



         catch (IOException e) {



            // TODO Auto-generated catch block



            e.printStackTrace();



         }



        



         return null;



      }



 



      @Override



      protected void onCancelled(Object result) {



         // TODO Auto-generated method stub



         super.onCancelled(result);



      }



 



      @Override



      protected void onPostExecute(Object result) {



         // TODO Auto-generated method stub



         super.onPostExecute(result);



        



         try



         {



            //创建一个JSON对象



            JSONObject jsonObject = new JSONObject(result.toString()).getJSONObject("parent");



            //获取某个对象的JSON数组



            JSONArray jsonArray = jsonObject.getJSONArray("children");



           



            StringBuilder builder = new StringBuilder();



           



            for(int i = 0; i<jsonArray.length(); i++)



            {



                //新建一个JSON对象，该对象是某个数组里的其中一个对象



                JSONObject jsonObject2 = (JSONObject)jsonArray.opt(i);



               



                builder.append(jsonObject2.getString("id")); //获取数据



                builder.append(jsonObject2.getString("title"));



                builder.append(jsonObject2.getString("name"));



            }



            myTextView.setText(builder.toString());



         }



         catch (JSONException e) {



            // TODO Auto-generated catch block



            e.printStackTrace();



         }



        



      }



 



      @Override



      protected void onPreExecute() {



         // TODO Auto-generated method stub



         //super.onPreExecute();



         Toast.makeText(getApplicationContext(), "开始HTTP GET请求", Toast.LENGTH_LONG).show();



      }



 



      @Override



      protected void onProgressUpdate(Object... values) {



         // TODO Auto-generated method stub



         super.onProgressUpdate(values);



      }



      



    }



}

android中json的浅薄理解

JSONObject 表示形式 {"key" : "value"}

JSONArray 表示形式  [{"key" : "value"},{"key" : "value"},{"key" : "value"}]，JSONArray里面包含多个JSONObject

访问时通过 JSONObject对象去访问，使用 jsonObject.getXXX("key")得到相应的值

一般解析JSON都使用这两个。