How to handle socket events as a background service in Android?

Question

I am new to Android development, and I wanted my application to detect socket events even when the application is not active through the Background service (so that I can give a push notification, for example, if there is a new message caused by a socket event like Whatsapp and others do this).

I implemented a background service and an application class that starts the service, but stuck where and how to put socket events as a Runnable task in my background service.

I modified the socket.io android chat sample project below and added a service and application class.

ChatApplication.java

package com.github.nkzawa.socketio.androidchat;

import android.app.Application;
import android.content.Intent;
import android.content.res.Configuration;

import io.socket.client.IO;
import io.socket.client.Socket;

import java.net.URISyntaxException;

public class ChatApplication extends Application {

    @Override
    // called when the application is starting, before any other application objects have been created
    public void onCreate() {
        super.onCreate();

        // represents our background service
        Intent background = new Intent(this, SocketBackgroundService.class);
        startService(background);
    }

    private Socket mSocket;
    {
        try {
            mSocket = IO.socket(Constants.CHAT_SERVER_URL);
        } catch (URISyntaxException e) {
            throw new RuntimeException(e);
        }
    }

    public Socket getSocket() {
        return mSocket;
    }
}

SocketBackgroundService.java

package com.github.nkzawa.socketio.androidchat;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

public class SocketBackgroundService extends Service {
    private boolean isRunning;
    private Thread backgroundThread;

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        this.isRunning = false;
        this.backgroundThread = new Thread(myTask);
    }

    private Runnable myTask = new Runnable() {
        @Override
        public void run() {
            // do something in here
            Log.i("INFO", "SOCKET BACKGROUND SERVICE IS RUNNING");

            //TODO - how to handle socket events here?
            //How do I do something like mSocket.on(Socket.EVENT_CONNECT,onConnect); here?
        }
    };

    @Override
    public void onDestroy() {
        this.isRunning = false;
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if( !this.isRunning) {
            this.isRunning = true;
            this.backgroundThread.start();
        }

        return START_STICKY;
    }
}

Answer 1

, . , .

Answer 2

. , ANR ( ), - . 5 . .
:

• Thread

• public class SocketBackgroundService extends Service {
  
  private SocketThread mSocketThread;
  
  @Override
  public IBinder onBind(Intent intent) {
      return null;
  }
  
  @Override
  public void onCreate() {
  
      mSocketThread = SocketThread.getInstance();
  }
  
  
  @Override
  public void onDestroy() {
      //stop thread and socket connection here
  }
  
  @Override
  public int onStartCommand(Intent intent, int flags, int startId) {
      if (mSocketThread.startThread) {
      } else {
          stopSelf();
      }
  
      return START_STICKY;
  }
  }
  
  public class SocketThread extends Thread {
  
  private static SocketThread mSocketThread;
  private SocketClient mSocketClient;
  
  private SocketThread() {
  }
  
  // create single instance of socket thread class
  public static SocketThread getInstance() {
      if (mSocketThread == null)//you can use synchronized also
      {
          mSocketThread = new SocketThread();
      }
      return mSocketThread;
  }
  
  
  public boolean startThread() {
              =new SocketClient();
      if (socketClient.isConnected()) {
          mSocketThread.start()
          return true;
      }
      return false;
  }
  
  @Override
  public void run() {
      super.run();
      while (mSocketClient.isConnected()) {
          // continue listen
      }
      // otherwise remove socketClient instance and stop thread
  }
  
  public class SocketClient {
      //write all code here regarding opening, closing sockets
      //create constructor
      public SocketClient() {
          // open socket connection here
      }
  
      public boolean isConnected() {
          return true;
      }
  }