在android應用程序中獲取jsonObject的空值

我有從json對象獲取值的問題.json_encode返回null到android的字符串。在android應用程序中獲取jsonObject的空值

的logcat：

05-01 22:36:21.653: D/Create Response(801): {} 

05-01 22:36:21.653: W/System.err(801): org.json.JSONException: No value 
for success 

05-01 22:36:21.663: W/System.err(801): at 

org.json.JSONObject.get(JSONObject.java:354) 

05-01 22:36:21.663: W/System.err(801): at 

org.json.JSONObject.getInt(JSONObject.java:443)

MyPhp.php

<?php 


header('Content-type=application/json; charset=utf-8'); 
$response = array(); 
// check for required fields 
if (isset($_POST['B_Name']) && isset($_POST['Au_Name']) && 
isset($_POST['Pub']) && isset($_POST['Pr']) && 
isset($_POST['B_Genre'])) { 

$B_Name = $_POST['B_Name']; 
$Au_Name = $_POST['Au_Name']; 
$Pub = $_POST['Pub']; 
$Pr = $_POST['Pr']; 
$B_Genre = $_POST['B_Genre']; 

// include db connect class 
require_once(__DIR__ . '/android/db_connect.php'); 

// connecting to db 
$db = new DB_CONNECT(); 

// mysql inserting a new row 
$result = mysql_query("INSERT INTO products(Book_Name, Author_Name, Book_Genre, Price, Publication) VALUES('$B_Name', '$Au_Name', '$B_Genre', '$Pr', '$Pub')"); 

// check if row inserted or not 
if ($result) { 
    // successfully inserted into database 
    $response["success"] = 1; 
    $response["message"] = "Product successfully created."; 


$encoded_rows = array_map('utf8_encode', $response); 
    echo json_encode($encoded_rows); 
} else { 
    // failed to insert row 
    $response["success"] = 0; 
    $response["message"] = "Oops! An error occurred."; 

    $encoded_rows = array_map('utf8_encode', $response); 
    echo json_encode($encoded_rows); 
    } 
} else { 

    $response["success"] = 0; 
    $response["message"] = "Required field(s) is missing"; 
    $encoded_rows = array_map('utf8_encode', $response); 
    echo json_encode($encoded_rows); 
    }

這裏是我的一片doInBackground的：

 String B_Name = BookName.getText().toString(); 
     String Au_Name = AuthorName.getText().toString(); 
     String Pub = Publication.getText().toString(); 
     String Pr = Price.getText().toString(); 
     String B_Genre = BookGenre.getText().toString(); 


     List<NameValuePair> params = new ArrayList<NameValuePair>(); 
     params.add(new BasicNameValuePair("B_Name", B_Name)); 
     params.add(new BasicNameValuePair("Au_Name", Au_Name)); 
     params.add(new BasicNameValuePair("Pub", Pub)); 
     params.add(new BasicNameValuePair("Pr", Pr)); 
     params.add(new BasicNameValuePair("B_Genre", B_Genre)); 

     // getting JSON Object 
     // Note that create product url accepts POST method 
     JSONObject json = jsonParser.makeHttpRequest(url_create_product, 
       "POST", params); 

     // check log cat fro response 
     Log.d("Create Response", json.toString()); 

     // check for success tag 
     try { 
      int success = json.getInt(TAG_SUCCESS); 

      if (success == 1) { 
       Intent i = new Intent(getApplicationContext(),  
     MainActivity.class); 
       startActivity(i); 
       finish(); 


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

來源

2015-04-30 hdiz

看起來像你的json字符串是空的：「{}」 – Buddy

好友 - 我知道，但爲什麼？ – hdiz

似乎問題是與PHP代碼。 check echo method of php。

我還沒有在php上工作，但我認爲echo json_encode($encoded_rows);聲明只是打印json的字符串格式。檢查你在哪裏返回json字符串作爲迴應。

來源

2015-05-01 06:22:48 seema

在android應用程序中獲取jsonObject的空值

回答

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