android - 作业计划程序未在 Android N 上运行

Question

Job Scheduler 在 Android Marshmallow 和 Lollipop 设备上按预期运行，但未运行且 Nexus 5x(Android N 预览版)。

调度作业的代码

        ComponentName componentName = new ComponentName(MainActivity.this, TestJobService.class.getName());
        JobInfo.Builder builder;
        builder = new JobInfo.Builder(JOB_ID, componentName);
        builder.setPeriodic(5000);
        JobInfo jobInfo;
        jobScheduler = (JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
        jobInfo = builder.build();
        int jobId = jobScheduler.schedule(jobInfo);

服务在 list 中定义为:

<service android:name=".TestJobService"
            android:permission="android.permission.BIND_JOB_SERVICE" />

有人在 Android N(预览版)上遇到这个问题吗？

Answer 1

在 Android Nougat 中， setPeriodic(long intervalMillis) 方法调用使用 setPeriodic (long intervalMillis, long flexMillis) 安排定期作业。

根据文档:

JobInfo.Builder setPeriodic (long intervalMillis, long flexMillis)

Specify that this job should recur with the provided interval and flex. The job can execute at any time in a window of flex length at the end of the period.

intervalMillis long: Millisecond interval for which this job will repeat. A minimum value of getMinPeriodMillis() is enforced.

flexMillis long: Millisecond flex for this job. Flex is clamped to be at least getMinFlexMillis() or 5 percent of the period, whichever is higher.

计划为 5 秒的示例定期作业:

private static final int JOB_ID = 1001;
private static final long REFRESH_INTERVAL  = 5 * 1000; // 5 seconds

JobInfo jobInfo = new JobInfo.Builder(JOB_ID, serviceName)
        .setPeriodic(REFRESH_INTERVAL)
        .setExtras(bundle).build();

上述代码在 Lollipop & Marshmallow 中运行良好，但在 Nougat 中运行时，您会注意到以下日志:

W/JobInfo: Specified interval for 1001 is +5s0ms. Clamped to +15m0s0ms
W/JobInfo: Specified flex for 1001 is +5s0ms. Clamped to +5m0s0ms

由于我们将周期性刷新间隔设置为小于阈值的 5 秒getMinPeriodMillis()。 Android Nougat 强制执行 getMinPeriodMillis()。

作为一种解决方法，如果作业间隔小于 15 分钟，我将使用以下代码定期安排作业。

JobInfo jobInfo;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
  jobInfo = new JobInfo.Builder(JOB_ID, serviceName)
      .setMinimumLatency(REFRESH_INTERVAL)
      .setExtras(bundle).build();
} else {
  jobInfo = new JobInfo.Builder(JOB_ID, serviceName)
      .setPeriodic(REFRESH_INTERVAL)
      .setExtras(bundle).build();
}

JobService 示例:

public class SampleService extends JobService {
    @Override public boolean onStartJob(JobParameters params) {
        doSampleJob(params); 
        return true;
    }

    @Override public boolean onStopJob(JobParameters params) {
        return false;
    }

    public void doSampleJob(JobParameters params) {
        // Do some heavy operation
        ...... 
        // At the end inform job manager the status of the job.
        jobFinished(params, false);
    }
}