java.net.SocketException: socket failed: EPERM (Operation not permitted)

I am working on an Android Studio project with several activities. I am currently trying to read the output from a Java Servlet on localhost but it seems to be crashing due to a socket permission.

I've made a new project, used the exact same code and worked perfectly. So I dont understand why is not willing to work on my project.

public class LoginActivity extends AppCompatActivity {


String apiUrl = "http://10.0.2.2:8080/ProyectService/Servlet?action=login";
EditText username;
EditText password;
AlertDialog dialog;
Usuario session;

@Override
public void onCreate(Bundle savedInstanceState) {
    // Inicializacion de ventana
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login);
    getSupportActionBar().hide();

    // Inicializacion de componentes
    username = findViewById(R.id.username);
    password = findViewById(R.id.password);

    // Inicializacion de funcionalidad de botones
    Button button= (Button) findViewById(R.id.login);
    button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            UserLoginTask mAuthTask = new UserLoginTask();
            mAuthTask.execute();
        }
    });

    password = findViewById(R.id.password);
    createAlertDialog("Usuario o Contraseña Incorrectos");
    }

    private void createAlertDialog(String message){
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage(message)
            .setTitle("Error");
    dialog = builder.create();
    }



    // ASYNCRONUS NETWORK PROCESS

    public class UserLoginTask extends AsyncTask<String, String, String> {

    @Override
    protected void onPreExecute() {
    }


    @Override
    protected String doInBackground(String... params) {

        // implement API in background and store the response in current variable
        String current = "";
        try {
            URL url;
            HttpURLConnection urlConnection = null;
            try {
                url = new URL(apiUrl);
                System.out.println(apiUrl);
                urlConnection = (HttpURLConnection) url
                        .openConnection();

                InputStream in = urlConnection.getInputStream();

                InputStreamReader isw = new InputStreamReader(in);

                int data = isw.read();
                while (data != -1) {
                    current += (char) data;
                    data = isw.read();
                    //System.out.print(current);

                }
                System.out.print(current);
                // return the data to onPostExecute method
                return current;

            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (urlConnection != null) {
                    urlConnection.disconnect();
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
            return "Exception: " + e.getMessage();
        }
        return current;
        }
    }

    protected void onPostExecute(String success) {
        Log.i(success, "");
       //attemptLogin();
    }
}

I Expect it to read the data but it crashes at this line:

InputStream in = urlConnection.getInputStream();

This is the error output:

java.net.SocketException: socket failed: EPERM (Operation not permitted)
at java.net.Socket.createImpl(Socket.java:492)
at java.net.Socket.getImpl(Socket.java:552)
at java.net.Socket.setSoTimeout(Socket.java:1180)
at com.android.okhttp.internal.io.RealConnection.connectSocket(RealConnection.java:143)
at com.android.okhttp.internal.io.RealConnection.connect(RealConnection.java:116)
at com.android.okhttp.internal.http.StreamAllocation.findConnection(StreamAllocation.java:186)
at com.android.okhttp.internal.http.StreamAllocation.findHealthyConnection(StreamAllocation.java:128)
at com.android.okhttp.internal.http.StreamAllocation.newStream(StreamAllocation.java:97)
at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:289)
at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:232)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:465)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:411)
at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:248)
at com.example.controller.LoginActivity$UserLoginTask.doInBackground(LoginActivity.java:114)
at com.example.controller.LoginActivity$UserLoginTask.doInBackground(LoginActivity.java:93)
at android.os.AsyncTask$3.call(AsyncTask.java:378)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:289)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
at java.lang.Thread.run(Thread.java:919)

Solution 1:

Solved: All I needed to do was to uninstall the app from the emulator or physical connected device and run it again.

Solution 2:

Just uninstall the app from the emulator then run again and it’ll work. I had the same issue

To uninstall the app run your project when "the application had stopped" message appear click "app info" then uninstall.