android.intent.action.SCREEN_ON
android.intent.action.SCREEN_OFF

android.intent.action.batteryprofile.SCR_OFF
android.intent.action.batteryprofile.SCR_ON

Intent startIntent=null;
@Override
 public void onStart(Intent intent, int startId) {
  startIntent=intent;
  IntentFilter filter=new IntentFilter();
  filter.addAction(Intent.ACTION_SCREEN_ON);
  filter.addAction(Intent.ACTION_SCREEN_OFF);
  receiver=new RelativeBroadcastReceiver();
  registerReceiver(receiver, filter);
  System.out.println("service onStart and action is "+intent.getAction());
  System.out.println("service onStart and startId is "+startId);
 };
 @Override
 public void onDestroy() {
  // TODO Auto-generated method stub
  System.out.println("service onDestroy");
  unregisterReceiver(receiver);
  if(startIntent!=null){
   System.out.println("serviceIntent not null");
   startService(startIntent);
  }

@Override
 public void onReceive(Context context, Intent intent) {
  // TODO Auto-generated method stub
  String action=intent.getAction();
  System.out.println("action is "+action);
  Intent lockIntent=new Intent(context,MyLockScreen.class);
  lockIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
  context.startActivity(lockIntent);
}

super.onCreate(savedInstanceState);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
setContentView(R.layout.main);