Job Scheduler未在Android N上运行

Job Scheduler在 Android Marshmallow和Lollipop设备上按预期工作,但它没有运行和Nexus 5x(Android N预览版).

用于安排作业的代码

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);

服务在清单中定义为：

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

在Android N(预览版)上是否有任何人遇到此问题？

解决方法

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

根据文件：

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.

示例定期作业计划为5秒：

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();

以上代码适用于Lollipop&棉花糖但是当你在牛轧糖中运行时你会注意到以下日志：

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

因为我们将周期性刷新间隔设置为5秒,小于thresholdgetMinPeriodMillis(). 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调度作业.

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();
}

示例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);
    }
}