public class MainActivity extends Activity {
 JobScheduler js;
 JobInfo.Builder builder;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  js=(JobScheduler) getSystemService(Context.JOB_SCHEDULER_SERVICE);
  builder=new Builder(1, new ComponentName(this, DemoService.class));
  builder.setRequiredNetworkType(JobInfo.NETWORK_TYPE_UNMETERED);
  js.schedule(builder.build());
 }
}

public class DemoService extends JobService{
 @Override
 public boolean onStartJob(JobParameters params) {
  // TODO Auto-generated method stub
  final JobParameters mJobParameters=params;
  AsyncTask<Void, Void, Void> mTask = new AsyncTask<Void, Void, Void>() {
  @Override
  protected Void doInBackground(Void... params) {
   // TODO Auto-generated method stub
   return null;
  }
  @Override
  protected void onPostExecute(Void result) {
   // TODO Auto-generated method stub
   Toast.makeText(wenfengService.this, "hello", 1000).show();
   jobFinished(mJobParameters, true);
   super.onPostExecute(result);
  }
  };
  mTask.execute();
  return true;
 }
 @Override
 public boolean onStopJob(JobParameters params) {
  // TODO Auto-generated method stub
  Toast.makeText(this, "bye", 1000).show();
  return true;
 }
}

<service
 android:name=".DemoService "
android:permission="android.permission.BIND_JOB_SERVICE"
 android:exported="true"/>

@Override
public boolean onStartJob(final JobParameters params) {
 mDownloadArtworkTask = new DownloadArtworkTask(this) {
 @Override
 protected void onPostExecute(Boolean success) {
  jobFinished(params, !success);
 }
 };
 mDownloadArtworkTask.execute();
 return true;
}

@Override
public boolean onStopJob(final JobParameters params) {
 if (mDownloadArtworkTask != null) {
 mDownloadArtworkTask.cancel(true);
 }
 return true;
}