android 지금 서비스가 동작 중인지 확인하는 코드

private Boolean isServiceRunning(String serviceName) {

ActivityManager activityManager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
for (RunningServiceInfo runningServiceInfo : activityManager.getRunningServices(Integer.MAX_VALUE)) {
if (serviceName.equals(runningServiceInfo.service.getClassName())) {
return true;
}
}
return false;
}