为什么android studio不跟踪响应侦听器？

Question

I have a simple register script in Android studio. I have the php script set to send a response when the code ran correctly. Android studio SHOULD receive a response, but doesn't.

here is the PHP chunk in question;

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

    echo $response;

And here is the CreateUser chunk in question;

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

                final String username = username1.getText().toString();
                final String password = password1.getText().toString();
                final String isadmin = isAdmin.getText().toString();
                Response.Listener<String> responseListener = new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        Log.d("Response Value: ", response);
                            if (response.equals("success")){
                                Intent intent = new Intent(CreateUser.this, MainActivity.class);
                                CreateUser.this.startActivity(intent);
                            }else{
                                AlertDialog.Builder builder = new AlertDialog.Builder(CreateUser.this);
                                builder.setMessage("Register Failed")
                                        .setNegativeButton("Retry",null)
                                        .create()
                                        .show();
                        }
                    }
                };
                RegisterRequest registerRequest = new RegisterRequest(username,password,isadmin,responseListener);
                RequestQueue queue = Volley.newRequestQueue(CreateUser.this);
                queue.add(registerRequest);
            }
        });
    }

and here is the registerrequest;

public class RegisterRequest extends StringRequest {

    private static final String REGISTER_REQUEST_URL = "http://192.168.*.*:80/phptesting/Register.php";
    private Map<String, String> params;
    public RegisterRequest(String username, String password,String isAdmin, Response.Listener<String> listener){
        super(Method.POST, REGISTER_REQUEST_URL,listener,null);
        params = new HashMap<>();
        params.put("username",username);
        params.put("password",password);
        params.put("isAdmin",isAdmin+"");
    }

Answer 1

You cannot echo an array in PHP. When you do that, the output will be

PHP Notice: Array to string conversion in php shell code on line 1
Array

You would need to send the string "success" directly, eg

echo "success";

Or serialize the array to JSON, but then you will have to change your ResponseListener so that it can understand that, probably with Jackson or whatever is available in Android.

A better alternative would be not to read the actual response body but just set the appropriate HTTP status code to indicate success or failure.