Android 中 判断给出的service是否是在运行中

public static boolean isServiceRunning(Context mContext, String className) {
boolean isRunning = false;
ActivityManager activityManager = (ActivityManager) mContext
.getSystemService(Context.ACTIVITY_SERVICE);
List<ActivityManager.RunningServiceInfo> serviceList = activityManager
.getRunningServices(30);
if (!(serviceList.size() > 0)) {
return false;
}
for (int i = 0; i < serviceList.size(); i++) {
if (serviceList.get(i).service.getClassName().equals(className)) {
isRunning = true;
break;
}
}
return isRunning;
}