没有得到JSON响应

Question

我有以下代码为“POST”请求，其中，我有一个API和参数。 但是，在这里我没有得到任何回应，也没有错误。 PLZ帮助我。

public JSONObject makeHttpRequest(String url, List<NameValuePair> params)  throws Exception {  
     // Making HTTP request 
     try { 
      Log.d("URL :", url); 
      Log.d("params :", params.toString()); 
       // defaultHttpClient 
       DefaultHttpClient httpClient = new DefaultHttpClient(); 
       HttpPost httpPost = new HttpPost(url); 
       httpPost.setEntity(new UrlEncodedFormEntity(params)); 
       HttpResponse httpResponse = httpClient.execute(httpPost); 
       HttpEntity httpEntity = httpResponse.getEntity(); 
       is = httpEntity.getContent(); 
      Log.d("InputStreem :", is.toString()); 
     } catch (UnsupportedEncodingException e) { 
      e.printStackTrace(); 
     } catch (ClientProtocolException e) { 
      e.printStackTrace(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
     try { 
      BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8); 
      Log.d("BufferedReader :", reader.toString()); 
        StringBuilder sb = new StringBuilder(); 
        String line = null; 
        while ((line = reader.readLine()) != null) { 
        sb.append(line + "\n"); 
        } 
        is.close(); 
        jsonResponse = sb.toString(); 
      System.out.println("Respose :"+jsonResponse);//Here Resonse: "nothing" 
     } catch (Exception e) { 
      throw new Exception(e.getMessage()); 
     } 
     // try parse the string to a JSON object 
     try { 
      jsonData = new JSONObject(jsonResponse); 
     } catch (JSONException e) { 
      throw new Exception(e.getMessage()); 
     } 
     // return JSON String 
     return jsonData; 
    } 

Answer 1

试试这个：

1. 定义JSON级。例如：

`

public class JSONParser { 

     static InputStream is = null; 
     static JSONObject jObj = null; 
     static String json = ""; 

     // constructor 
     public JSONParser() { 

     } 

     public JSONObject getJSONFromUrl(String url, List<NameValuePair> params) { 

      // Making HTTP request 
      try { 
       // defaultHttpClient 
       DefaultHttpClient httpClient = new DefaultHttpClient(); 
       HttpPost httpPost = new HttpPost(url); 
       httpPost.setEntity(new UrlEncodedFormEntity(params)); 

       HttpResponse httpResponse = httpClient.execute(httpPost); 
       HttpEntity httpEntity = httpResponse.getEntity(); 
       is = httpEntity.getContent(); 

      } catch (UnsupportedEncodingException e) { 
       e.printStackTrace(); 
      } catch (ClientProtocolException e) { 
       e.printStackTrace(); 
      } catch (IOException e) { 
       e.printStackTrace(); 
      } 

      try { 
       BufferedReader reader = new BufferedReader(new InputStreamReader(
         is, "iso-8859-1"), 8); 
       StringBuilder sb = new StringBuilder(); 
       String line = null; 
       while ((line = reader.readLine()) != null) { 
        sb.append(line + "\n"); 
       } 
       is.close(); 
       json = sb.toString(); 
       Log.e("JSON", json); 
      } catch (Exception e) { 
       Log.e("Buffer Error", "Error converting result " + e.toString()); 
      } 

      // try parse the string to a JSON object 
      try { 
       jObj = new JSONObject(json); 
      } catch (JSONException e) { 
       Log.e("JSON Parser", "Error parsing data " + e.toString()); 
      } 

      // return JSON String 
      return jObj; 

     } } 

定义函数级，其包含了所有你的应用将与服务器进行通信的功能。例如：

公共类UserFunctions {

private JSONParser jsonParser; 

// URL of the API 
private static String functionURL = "http://xxx.xxx.xxx.xx/.../"; 

// TAG to determine which function/query should be executed on serverside 
// e.g. with IF-ELSE 
private static String function_tag = "getData"; 

// Constructor 
public UserFunctions() { 
    jsonParser = new JSONParser(); 
} 

/** 
* FUNCTION GetSomeData 
**/ 

// Here you can define functions, and give parameters (if you need) 
// and catch those on serverside with POST as their names 
// you defined in qoutes, in this example you could catch the 2 parameters 
// with 
// $email = $_POST['email']; and $password = $_POST['password']; (assumed 
// you use PHP) 

public JSONObject functionGetData(String parameter1, String parameter2) { 
    // Building Parameters 
    List<NameValuePair> params = new ArrayList<NameValuePair>(); 
    params.add(new BasicNameValuePair("tag", function_tag)); 
    params.add(new BasicNameValuePair("email", parameter1)); 
    params.add(new BasicNameValuePair("password", parameter1)); 
    JSONObject json = jsonParser.getJSONFromUrl(functionURL, params); 
    return json; 
}} 

使用AsynchTask获取JSON数据。例如：

私有类FetchDataTask扩展 的AsyncTask {

String parameter1, parameter2; 

    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
     // Define variables here (if needed), that will be commited to 
     // function/method in 
     // doInBackground() as parameters 

    } 

    @Override 
    protected JSONObject doInBackground(String... args) { 

     UserFunctions userFunction = new UserFunctions(); 

     JSONObject json = userFunction.functionGetData(parameter1, 
       parameter2); 

     return json; 

    } 

    @Override 
    protected void onPostExecute(JSONObject json) { 

     try { 

      // Catch data from JSON 
      // Create JSON object and get it by calling method 
      // getString("data") 
      // on serverside json: 
      // $response["jsonObj"]["data"] = $SQL_result['columnXY']; 

      JSONObject json_object = json.getJSONObject("jsonObj"); 

      String data = json_object.getString("data"); 

     } catch (JSONException e) { 
      e.printStackTrace(); 

     } 

    }} 

希望它能帮助。