android - 检查服务是否已经在运行

Question

我有一项服务在我的 Android 应用程序的应用程序类中启动。

该服务每小时运行一次，我不希望它在每次打开应用程序时都启动，这似乎是它现在所做的。我想检查它是否正在运行，如果没有，则运行它。

I found this code在另一个我认为可行的答案中，但如果我运行该应用程序两次，我仍然会从以下代码中收到消息“服务未运行，计划作业”:

public class App extends Application {

    public static final String TAG = "Application";
    public static final int JOB_NUMBER = 3007;

    @Override
    public void onCreate() {
        super.onCreate();
        if(!isMyServiceRunning(DevotionalService.class)) {
            ComponentName componentName = new ComponentName(this, DevotionalService.class);
            JobInfo info = new JobInfo.Builder(JOB_NUMBER, componentName)
                    .setRequiresCharging(false)
                    .setRequiredNetworkType(JobInfo.NETWORK_TYPE_UNMETERED)
                    .setPersisted(true)
                    .setPeriodic(60 * 60 * 1000)
                    .build();
            JobScheduler scheduler = (JobScheduler) getSystemService(JOB_SCHEDULER_SERVICE);
            int resultCode = scheduler.schedule(info);
            if (resultCode == JobScheduler.RESULT_SUCCESS) {
                Log.d(TAG, "Service is not running, Job Scheduled.");
            } else {
                Log.d(TAG, "Service is not running, However job scheduling failed.");
            }
        } else {
            Log.d(TAG, "Service is already running.");
        }
    }

    private boolean isMyServiceRunning(Class<?> serviceClass) {
        ActivityManager manager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
        for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) {
            if (serviceClass.getName().equals(service.service.getClassName())) {
                return true;
            }
        }
        return false;
    }

    public void cancelJob() {
        JobScheduler scheduler = (JobScheduler) getSystemService(JOB_SCHEDULER_SERVICE);
        scheduler.cancel(JOB_NUMBER);
        Log.d(TAG, "Job Cancelled.");
    }
}

有人知道为什么会这样吗？

Answer 1

检查服务是否正在运行:

class MyService extends Service {
   private static boolean isRunning;
   public int onStartCommand (Intent intent, 
                int flags, 
                int startId) {
        isRunning = true;
        ...
   }
   public void onDestroy() {
       isRunning = false;
   }
   public static boolean isRunning() { 
       return isRunning;
   }
}

然后检查它是否正在运行，只需检查 MyService.isRunning()。

检查服务是否已安排:

if(JobScheduler.getPendingJob(jobID) == null) {
   //job notscheduled
}