Как решить JSONException

Я пытаюсь сделать страницу регистрации из активности приложения Android, связывающей данные с моей базой данных SQL, но всякий раз, когда я запускаю ее, я получаю эту ошибку:

W / System.err: org.json.JSONException: значение типа java.lang.String
не может быть преобразован в JSONObject

, Как решить эту проблему?

этот класс регистров

public class RegistrationActivity extends AppCompatActivity {

private static final String TAG = "RegisterActivity";
private static final String URL_FOR_REGISTRATION = "http://192.168.1.33/arswebservices/register.php";
ProgressDialog progressDialog;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_registration);
final EditText NameRegister = (EditText) findViewById(R.id.reg_UserName);
final  EditText EmailRegister = (EditText) findViewById(R.id.reg_Email);
final EditText PasswordRegister = (EditText)                                           findViewById(R.id.reg_Password);
Button registrationButton = (Button) findViewById(R.id.reg_Button);

// Progress dialog
progressDialog = new ProgressDialog(this);
progressDialog.setCancelable(false);
registrationButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
registerUser(NameRegister.getText().toString(), EmailRegister.getText().toString(),
PasswordRegister.getText().toString());
}
});
}

private void registerUser(final String name,  final String email, final String password) {
// Tag used to cancel the request
String cancel_req_tag = "register";

progressDialog.setMessage("Adding you ...");
showDialog();

StringRequest strReq = new StringRequest(Request.Method.POST,
URL_FOR_REGISTRATION, new Response.Listener<String>() {

@Override
public void onResponse(String response) {
Log.d(TAG, "Register Response: " + response.toString());
hideDialog();

try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("error");


if (!error) {
String user = jObj.getJSONObject("user").getString("name");
Toast.makeText(getApplicationContext(), "Hi " + user +", You are successfully Added!", Toast.LENGTH_SHORT).show();

// Launch login activity
Intent intent = new Intent(
RegistrationActivity.this,
LoginActivity.class);
startActivity(intent);
finish();
} else {

String errorMsg = jObj.getJSONObject("user").getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}

}
}, new Response.ErrorListener() {

@Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Registration Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
@Override
protected Map<String, String> getParams() {
// Posting params to register url
Map<String, String> params = new HashMap<String, String>();
params.put("name", name);
params.put("email", email);
params.put("password", password);
return params;
}
};
// Adding request to request queue
AppSingleton.getInstance(getApplicationContext()).addToRequestQueue(strReq, cancel_req_tag);
}

private void showDialog() {
if (!progressDialog.isShowing())
progressDialog.show();
}

private void hideDialog() {
if (progressDialog.isShowing())
progressDialog.dismiss();
}
}