android：通过php连接mysql（WAMP设置） - 应用程序崩溃

Question

我是android新手，所以任何建议都会非常有帮助。

我想通过PHP连接Mysql，但应用程序在尝试连接时崩溃。

private class ProcessLogin extends AsyncTask<String, String, JSONObject> { 
      private ProgressDialog pDialog; 
      String email,password; 
      @Override 
      protected void onPreExecute() { 
       super.onPreExecute(); 
       inputEmail = (EditText) findViewById(R.id.email); 
       inputPassword = (EditText) findViewById(R.id.pword); 
       email = inputEmail.getText().toString(); 
       password = inputPassword.getText().toString(); 
       pDialog = new ProgressDialog(login.this); 
       pDialog.setTitle("Contacting Servers"); 
       pDialog.setMessage("Logging in ..."); 
       pDialog.setIndeterminate(false); 
       pDialog.setCancelable(true); 
       pDialog.show(); 
      } 

      protected JSONObject doInBackground(String... args) { 
       UserFunctions userFunction = new UserFunctions(); 
       JSONObject json = userFunction.loginUser(email, password); 
       return json; 
      } 

下的DB_CONFIG文件是这样的：

define('DB_USER', "root"); // db user 
    define('DB_PASSWORD', ""); // db password (mention your db password here) 
    define('DB_DATABASE', "aap1"); // database name 
    define('DB_SERVER', "localhost"); // db server 

我加入数据库中的表项。

此外，函数调用如下：

public JSONObject loginUser(String email, String password){ 
      // Building Parameters 
      List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(); 
      params.add(new BasicNameValuePair("tag", Custlogin_tag)); 
      params.add(new BasicNameValuePair("email", email)); 
      params.add(new BasicNameValuePair("password", password)); 
      JSONObject json = jsonParser.getJSONFromUrl(loginURL, params); 
      return json; 
     } 

    private static String loginURL = "http://127.0.0.1/app1/index.php"; 

下面是logcat的：

10-07 23:22:40.596: E/Buffer Error(2003): Error converting result java.lang.NullPointerException: lock == null 
    10-07 23:22:40.676: E/JSON Parser(2003): Error parsing data org.json.JSONException: End of input at character 0 of 
    10-07 23:22:40.766: E/AndroidRuntime(2003): FATAL EXCEPTION: main 
    10-07 23:22:40.766: E/AndroidRuntime(2003): Process: com.example.app1, PID: 2003 
    10-07 23:22:40.766: E/AndroidRuntime(2003): java.lang.NullPointerException 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at com.example.app1.login$ProcessLogin.onPostExecute(login.java:180) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at com.example.aap1.login$ProcessLogin.onPostExecute(login.java:1) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at android.os.AsyncTask.finish(AsyncTask.java:632) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at android.os.AsyncTask.access$600(AsyncTask.java:177) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:645) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at android.os.Handler.dispatchMessage(Handler.java:102) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at android.os.Looper.loop(Looper.java:136) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at android.app.ActivityThread.main(ActivityThread.java:5017) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at java.lang.reflect.Method.invokeNative(Native Method) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at java.lang.reflect.Method.invoke(Method.java:515) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 
    10-07 23:22:40.766: E/AndroidRuntime(2003):  at dalvik.system.NativeStart.main(Native Method) 

JSON解析器如下：

`public JSONObject getJSONFromUrl(String url, List<?> params) { 
     // Making HTTP request 
     try { 
      // defaultHttpClient 
      DefaultHttpClient httpClient = new DefaultHttpClient(); 
      HttpPost httpPost = new HttpPost(url); 
      httpPost.setEntity(new UrlEncodedFormEntity 
      ((List<? extends NameValuePair>) 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(); 
     }` 

和PHP脚本：

`if ($tag == 'login') { 
     // Request type is check Login 
     $email = $_POST['email']; 
     $password = $_POST['password']; 
     // check for user 
     $user = $db->getUserByEmailAndPassword($email, $password); 
     if ($user != false) { 
      // user found 
      // echo json with success = 1 
      $response["success"] = 1; 
      $response["user"]["email"] = $user["email"]; 
      $response["user"]["uname"] = $user["username"]; 
      $response["user"]["uid"] = $user["unique_id"]; 
      $response["user"]["created_at"] = $user["created_at"]; 
      echo json_encode($response); 
     } else { 
      // user not found 
      // echo json with error = 1 
      $response["error"] = 1; 
      $response["error_msg"] = "Incorrect email or password!"; 
      echo json_encode($response); 
     }` 

和DB函数为：

` public function getUserByEmailAndPassword($email, $password) { 
        $result = mysqli_query("SELECT * FROM users WHERE email = '$email'") 
     or die(mysqli_error()); 
        // check for result 
        $no_of_rows = mysqli_num_rows($result); 
        if ($no_of_rows > 0) { 
            $result = mysqli_fetch_array($result); 
            $salt = $result['salt']; 
            $encrypted_password = $result['encrypted_password']; 
            $hash = $this->checkhashSSHA($salt, $password); 
            // check for password equality 
            if ($encrypted_password == $hash) { 
                // user authentication details are correct 
                return $result; 
            } 
        } else { 
            // user not found 
            return false; 
        } 
   }` 

我已经测试通过testmysql.php数据库连接，这是罚款。

Answer 1

变化

List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>(); 

由于List<NameValuePair> params = new ArrayList<NameValuePair>();