A sample activity monitoring the network connectivity of an android device

connection_monitoring.java

package com.webile.network;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);        
        registerReceiver(networkStateReceiver, filter);
    }
    
    BroadcastReceiver networkStateReceiver = new BroadcastReceiver() {
    	
        @Override
        public void onReceive(Context context, Intent intent) {
        	boolean noConnectivity = intent.getBooleanExtra(ConnectivityManager.EXTRA_NO_CONNECTIVITY, false);
        	
            if(!noConnectivity) {
            		onConnectionFound();
            } else {
            		onConnectionLost();
            }
        }
    };

   
    public void onConnectionLost() {
    	Toast.makeText(this, "Connection lost", Toast.LENGTH_LONG).show();
    }
    
    public void onConnectionFound() {
    	Toast.makeText(this, "Connection found", Toast.LENGTH_LONG).show();
    }
    
    @Override
    protected void onDestroy() {
    	super.onDestroy();
    	unregisterReceiver(networkStateReceiver);
    }
}