org.json.JSONException：值

Question

I'm trying to get an android app developed in Android studio to send data from a Register user activity to a database. The idea is once the user types in all the required information and clicks the register button the data should go to a database and the Login activity should re-appear. However, when I click on the register button on the Register user activity nothing is happening, no redirection to Login activity or data being sent to database.

Below is my Register user activity code:

package com.example.vi5h.split;
import android.content.Intent;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.toolbox.Volley;
import org.json.JSONException;
import org.json.JSONObject;

public class RegisterUserActivity extends AppCompatActivity {

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

    final EditText etFullName = (EditText) findViewById(R.id.etFullName);
    final EditText etUsername = (EditText) findViewById(R.id.etUsername);
    final EditText etPassword = (EditText) findViewById(R.id.etPassword);
    final EditText etEmail = (EditText) findViewById(R.id.etEmail);
    final Button btnRegister = (Button) findViewById(R.id.btnRegister);

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

            final String name = etFullName.getText().toString();
            final String username = etUsername.getText().toString();
            final String password = etPassword.getText().toString();
            final String email = etEmail.getText().toString();

            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(RegisterUserActivity.this, LoginActivity.class);
                            RegisterUserActivity.this.startActivity(intent);

                        }else {
                            AlertDialog.Builder builder = new AlertDialog.Builder(RegisterUserActivity.this);
                            builder.setMessage("Register Failed")
                                    .setNegativeButton("Retry", null)
                                    .create()
                                    .show();
                        }


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


                }
            };


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


        }
    });



}
}

Below is my Register request class code:

package com.example.vi5h.split;
import com.android.volley.Response;
import com.android.volley.toolbox.StringRequest;
import java.util.HashMap;
import java.util.Map;


public class RegisterRequest extends StringRequest {

private static final String REGISTER_REQUEST_URL = "https://split.000webhostapp.com/Register.php";
private Map<String, String> params;

public RegisterRequest(String name, String username, String email, String password, Response.Listener<String> listener)
{

    super(Method.POST, REGISTER_REQUEST_URL, listener, null);
    params = new HashMap<>();
    params.put("name", name);
    params.put("username", username);
    params.put("email", email);
    params.put("password", password);
}


@Override
public Map<String, String> getParams() {
    return params;
}
}

Below is my PHP script (Register.php):

<?php
$con = mysqli_connect("localhost", "id2833909_split421", "pass321", "id2833909_splitw");

$name = $_POST["name"];
$email = $_POST["email"];
$username = $_POST["username"];
$password = $_POST["password"];
$statement = mysqli_prepare($con, "INSERT INTO user (name, username, email, password) VALUES (?, ?, ?, ?)");
mysqli_stmt_bind_param($statement, "siss", $name, $username, $email, $password);
mysqli_stmt_execute($statement);

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

echo json_encode($response);
?>

And finnally below is the error thrown on Logcat after I tapped the Register button: https://imgur.com/b8x0Su6

Answer 1

If you visit https://split.000webhostapp.com/Register.php in a Web browser, you get back broken content. It is not a complete Web page, but instead is a bunch of error messages:

<br />
<b>Notice</b>:  Undefined index: name in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>4</b><br />
<br />
<b>Notice</b>:  Undefined index: email in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>5</b><br />
<br />
<b>Notice</b>:  Undefined index: username in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>6</b><br />
<br />
<b>Notice</b>:  Undefined index: password in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>7</b><br />
<br />
<b>Warning</b>:  mysqli_stmt_bind_param() expects parameter 1 to be mysqli_stmt, boolean given in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>9</b><br />
<br />
<b>Warning</b>:  mysqli_stmt_execute() expects parameter 1 to be mysqli_stmt, boolean given in <b>/storage/ssd5/909/2833909/public_html/Register.php</b> on line <b>10</b><br />
{"success":true}

The first three characters of that response are <br . Those happen to be the first three characters that the JSON parser is complaining about in your error message. So, my guess is that the Web server is sending back the same sort of broken content in response to your Volley request.

So, take a look at response and see what you are getting as plain text. Then, fix whatever problem the response indicates.