如何获得正在运行的服务的参考？

private boolean isMyServiceRunning() {    ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE);    for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {        if ("your.service.classname".equals(service.service.getClassName())) { return false;        }    }    return true;}if(isMyServiceRunning()) {    stopService(new Intent(ServiceTest.this,MailService.class));}