Java tutorial
package android.support.v4.app; import android.app.job.JobParameters; import android.app.job.JobServiceEngine; import android.app.job.JobWorkItem; import android.content.Intent; import android.os.Build; import android.os.IBinder; import android.support.annotation.RequiresApi; import android.util.Log; public abstract class SafeJobIntentService extends JobIntentService { @Override public void onCreate() { super.onCreate(); if (Build.VERSION.SDK_INT >= 26) { mJobImpl = new SafeJobServiceEngineImpl(this); } } /** * Implementation of a safe JobServiceEngine for interaction with JobIntentService. */ @RequiresApi(26) static final class SafeJobServiceEngineImpl extends JobServiceEngine implements JobIntentService.CompatJobEngine { static final String TAG = "JobServiceEngineImpl"; static final boolean DEBUG = false; final JobIntentService mService; final Object mLock = new Object(); JobParameters mParams; final class WrapperWorkItem implements JobIntentService.GenericWorkItem { final JobWorkItem mJobWork; WrapperWorkItem(JobWorkItem jobWork) { mJobWork = jobWork; } @Override public Intent getIntent() { return mJobWork.getIntent(); } @Override public void complete() { synchronized (mLock) { if (mParams != null) { try { mParams.completeWork(mJobWork); } catch (SecurityException e) { Log.e(TAG, Log.getStackTraceString(e)); } } } } } SafeJobServiceEngineImpl(JobIntentService service) { super(service); mService = service; } @Override public IBinder compatGetBinder() { return getBinder(); } @Override public boolean onStartJob(JobParameters params) { if (DEBUG) Log.d(TAG, "onStartJob: " + params); mParams = params; // We can now start dequeuing work! mService.ensureProcessorRunningLocked(false); return true; } @Override public boolean onStopJob(JobParameters params) { if (DEBUG) Log.d(TAG, "onStartJob: " + params); boolean result = mService.doStopCurrentWork(); synchronized (mLock) { // Once we return, the job is stopped, so its JobParameters are no // longer valid and we should not be doing anything with them. mParams = null; } return result; } /** * Dequeue some work. */ @Override public JobIntentService.GenericWorkItem dequeueWork() { JobWorkItem work = null; synchronized (mLock) { if (mParams == null) { return null; } try { work = mParams.dequeueWork(); } catch (SecurityException e) { Log.e(TAG, Log.getStackTraceString(e)); } } if (work != null) { work.getIntent().setExtrasClassLoader(mService.getClassLoader()); return new WrapperWorkItem(work); } else { return null; } } } }