android 判断service是否正在运行

public static boolean isServiceExisted(Context context, String className) {
        ActivityManager activityManager = (ActivityManager) context
                .getSystemService(Context.ACTIVITY_SERVICE);
        List<ActivityManager.RunningServiceInfo> serviceList = activityManager
                .getRunningServices(Integer.MAX_VALUE);

        if (!(serviceList.size() > 0)) {
            return false;
        }

        for (int i = 0; i < serviceList.size(); i++) {
            RunningServiceInfo serviceInfo = serviceList.get(i);
            ComponentName serviceName = serviceInfo.service;

            if (serviceName.getClassName().equals(className)) {
                return true;
            }
        }
        return false;
    }