ExecutorService para manejar tareas asíncronas

ExecutorService.java

import android.os.Bundle;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ExampleActivity extends AppCompatActivity {

    private TextView textView;
    private ExecutorService executorService;

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

        textView = findViewById(R.id.textView);

        // Inicializar ExecutorService
        executorService = Executors.newSingleThreadExecutor();

        // Ejecutar tarea asíncrona para conectar via socket
        executorService.execute(new Runnable() {
            @Override
            public void run() {
                // Realiza la tarea de conexión de socket en el hilo de fondo
                final String result = connectToServer();

                // Actualiza la UI con el resultado
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        updateUI(result);
                    }
                });
            }
        });
    }

    private String connectToServer() {
        String serverIp = "172.172.172.172";
        int serverPort = 1234; // Asegúrate de que el puerto sea correcto
        String messageToSend = "Hello, Server!";
        StringBuilder response = new StringBuilder();

        try (Socket socket = new Socket(serverIp, serverPort);
             OutputStream outputStream = socket.getOutputStream();
             BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()))) {

            // Enviar mensaje al servidor
            outputStream.write(messageToSend.getBytes());
            outputStream.flush();

            // Leer la respuesta del servidor
            String line;
            while ((line = reader.readLine()) != null) {
                response.append(line).append('\n');
            }

        } catch (Exception e) {
            e.printStackTrace();
            return "Error: " + e.getMessage();
        }
        return response.toString();
    }

    private void updateUI(String result) {
        textView.setText(result);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        executorService.shutdown();
    }
}