如何解决org.json.JSONException：值 分类: 技术问答 • 2022-04-21 11:30:48

Question

我目前正在开发一个注册登录应用程序。我面临这个问题，我找不到任何可以解决问题的解决方案。任何人都可以解决这个问题吗？帮助将不胜感激。如何解决org.json.JSONException：值<java.lang.String类型的DOCTYPE不能被转换为JSONObject的

RegisterActivity.java

public class RegisterActivity extends AppCompatActivity { 
AlertDialog.Builder builder; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_register); 

    builder = new AlertDialog.Builder(RegisterActivity.this); 
    final EditText etName = (EditText) findViewById(R.id.etName); 
    final EditText etUserName = (EditText) findViewById(R.id.etUserName); 
    final EditText etPassword = (EditText) findViewById(R.id.etPassword); 
    final EditText etAge = (EditText) findViewById(R.id.etAge); 
    final EditText etEmail = (EditText) findViewById(R.id.etEmail); 
    final Button bRegister = (Button) findViewById(R.id.bRegister); 

    bRegister.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 

      final String name = etName.getText().toString(); 
      final String username = etUserName.getText().toString(); 
      final String password = etPassword.getText().toString(); 
      final int age = Integer.parseInt(etAge.getText().toString()); 
      final String email = etEmail.getText().toString(); 

      if (name.equals("") || username.equals("") || password.equals("") || age == 0 || email.equals("")) { 
       builder.setTitle("Something Went Wrong"); 
       builder.setMessage("Please fill in all the fileds").setPositiveButton("OK", null).create().show(); 

      } else { 

       Response.Listener<String> responseListener = new Response.Listener<String>() { 
        @Override 
        public void onResponse(String response) { 

         try { 
          JSONObject jsonResponse = new JSONObject(response); 
          boolean success = jsonResponse.getBoolean("success"); 

          if (success) { 
           Intent intent = new Intent(RegisterActivity.this, LoginActivity.class); 
           RegisterActivity.this.startActivity(intent); 
          } else { 
           builder = new AlertDialog.Builder(RegisterActivity.this); 
           builder.setMessage("Registration Failed").setNegativeButton("Retry", null).create().show(); 

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


       }; 
       RegisterRequest registerRequest = new RegisterRequest(name, username, password, age, email, responseListener); 
       RequestQueue queue = Volley.newRequestQueue(RegisterActivity.this); 
       queue.add(registerRequest); 


      } 
     } 

    }); 
} 

Register.php

<?php 

    $servername = "mysql6.000webhost.com"; 
    $username = "a5124128_user"; 
    $password = "paddwoed4896"; 
    $dbname = "a5124128_account"; 


    $con = mysqli_connect($servername, $username, $password, $dbname) or die(mysql_error()); 

    $db_selected = mysql_selectdb($con, $dbname); 

    $name = $_POST["name"]; 
    $username = $_POST["username"]; 
    $password = $_POST["password"]; 
    $age = $_POST["age"]; 
    $email = $_POST["email"]; 

    $statement = mysqli_prepare($con, "INSERT INTO user (name, username, password, age, email) VALUES (?, ?, ?, ?, ?)"); 
    mysqli_stmt_bind_param($statement, "sssis", $name, $username, $password, $age, $email); 
    mysqli_stmt_execute($statement); 

    $response = array();; 
    $response["success"] = true; 

    echo json_encode($response); 

?> 

以下是logcat的

09-25 15:41:50.697 17259-17259/com.example.chang.e_ktm W/System.err: org.json.JSONException: Value <!DOCTYPE of type java.lang.String cannot be converted to JSONObject 
09-25 15:41:50.698 17259-17259/com.example.chang.e_ktm W/System.err:  at org.json.JSON.typeMismatch(JSON.java:111) 
09-25 15:41:50.698 17259-17259/com.example.chang.e_ktm W/System.err:  at org.json.JSONObject.<init>(JSONObject.java:160) 
09-25 15:41:50.698 17259-17259/com.example.chang.e_ktm W/System.err:  at org.json.JSONObject.<init>(JSONObject.java:173) 
09-25 15:41:50.698 17259-17259/com.example.chang.e_ktm W/System.err:  at com.example.chang.e_ktm.RegisterActivity$1$1.onResponse(RegisterActivity.java:78) 
09-25 15:41:50.698 17259-17259/com.example.chang.e_ktm W/System.err:  at com.example.chang.e_ktm.RegisterActivity$1$1.onResponse(RegisterActivity.java:73) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:67) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at android.os.Handler.handleCallback(Handler.java:815) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at android.os.Handler.dispatchMessage(Handler.java:104) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at android.os.Looper.loop(Looper.java:210) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at android.app.ActivityThread.main(ActivityThread.java:5830) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at java.lang.reflect.Method.invoke(Native Method) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at java.lang.reflect.Method.invoke(Method.java:372) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1113) 
09-25 15:41:50.699 17259-17259/com.example.chang.e_ktm W/System.err:  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:879) 

有人可以帮我这个问题？这个问题似乎喜欢上了response.listener

邮差结果

http://i.stack.imgur.com/4dBM6.png

Answer 1

你没有得到从php api适当的反应发生。所以请检查api一次使用任何REST client像邮递员。

Answer 2

“Value <！DOCTYPE”似乎表示您没有收到JSON有效负载，但是是HTML one。这意味着问题可能会留在您的服务器端，在echo json_encode($response);之前崩溃并生成错误页面（极有可能是'500服务器错误'）。

为了确认，请尝试从浏览器访问URL发送相同的有效载荷（尝试GET） - 看看有什么反应回来。

或者只是开始调试你的PHP脚本里面设置一些断点，然后触发从客户端请求（你设置你的PHP调试到您的IDE，不是吗？）。