如何解决org.json.JSONException：Value

Question

I'm currently developing a register login application. I'm facing this problem and i can't find any solution that can solve the problem. Anyone have any solution about this? Help will be greatly appreciated.

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);

?>

The following is the logcat

    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)

Can someone please help me about this problem? The problem seems like occur on the response.listener

POSTMAN result

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

Answer 1

You are not getting proper response from your php api . So check that api once using any REST client like postman.

Answer 2

The "Value <!DOCTYPE" seems to indicate you are not receiving a JSON payload, but a HTML one . Which means that the problem may stay on your server side, crashing before the echo json_encode($response); and generating an error page (highly probable a '500 server error').

To confirm, try sending the same payload by accessing the URL from a browser (try a GET) - see what response comes back.

Or just start debugging your PHP script set some breakpoints inside and then trigger the request from the clients side (you setup your PHP debugging into your IDE, haven't you?).