An utility library for Android to run jobs delayed in the background. Depending on the Android version either the JobScheduler, GcmNetworkManager or AlarmManager is getting used. You can find out in this blog post why you should prefer this library than each separate API.
Download the latest version or grab via Gradle:
dependencies {
compile 'com.evernote:android-job:1.0.2'
}If you didn't turn off the manifest merger from the Gradle build tools, then no further step is required to setup the library. Otherwise you manually need to add the permissions and services like in this AndroidManifest.
The class JobManager serves as entry point. Your jobs need to extend the class Job. Create a JobRequest with the corresponding builder class and schedule this request with the JobManager.
Before you can use the JobManager you must initialize the singleton. You need to provide a Context and add a JobCreator implementation after that. The JobCreator maps a job tag to a specific job class. It's recommend to initialize the JobManager in the onCreate() method of your Application object.
public class App extends Application {
@Override
public void onCreate() {
super.onCreate();
JobManager.create(this).addJobCreator(new DemoJobCreator());
}
}public class DemoJobCreator implements JobCreator {
@Override
public Job create(String tag) {
switch (tag) {
case DemoJob.TAG:
return new DemoJob();
default:
return null;
}
}
}After that you can start scheduling jobs.
public class DemoJob extends Job {
public static final String TAG = "job_demo_tag";
@Override
@NonNull
protected Result onRunJob(Params params) {
// run your job
return Result.SUCCESS;
}
}
private void scheduleJob() {
new JobRequest.Builder(DemoJob.TAG)
.setExecutionWindow(30_000L, 40_000L)
.build()
.schedule();
}The JobRequest.Builder class has many extra options, e.g. you can specify a required network connection, make the job periodic, pass some extras with a bundle, restore the job after a reboot or run the job at an exact time.
Each job has a unique ID. This ID helps to identify the job later to update requirements or to cancel the job.
private void scheduleAdvancedJob() {
PersistableBundleCompat extras = new PersistableBundleCompat();
extras.putString("key", "Hello world");
int jobId = new JobRequest.Builder(DemoJob.TAG)
.setExecutionWindow(30_000L, 40_000L)
.setBackoffCriteria(5_000L, JobRequest.BackoffPolicy.EXPONENTIAL)
.setRequiresCharging(true)
.setRequiresDeviceIdle(false)
.setRequiredNetworkType(JobRequest.NetworkType.CONNECTED)
.setExtras(extras)
.setRequirementsEnforced(true)
.setPersisted(true)
.build()
.schedule();
}
private void schedulePeriodicJob() {
int jobId = new JobRequest.Builder(DemoJob.TAG)
.setPeriodic(60_000L)
.setPersisted(true)
.build()
.schedule();
}
private void scheduleExactJob() {
int jobId = new JobRequest.Builder(DemoJob.class)
.setExact(20_000L)
.setPersisted(true)
.build()
.schedule();
}
private void cancelJob(int jobId) {
JobManger.instance().cancel(jobId);
}If a non periodic Job fails, then you can reschedule it with the defined back-off criteria.
public class RescheduleDemoJob extends Job {
@Override
@NonNull
protected Result onRunJob(Params params) {
// something strange happened, try again later
return Result.RESCHEDULE;
}
@Override
protected void onReschedule(int newJobId) {
// the rescheduled job has a new ID
}
}Warning: With Android Marshmallow Google introduced the auto backup feature. All job information are stored in a shared preference file called evernote_jobs.xml and in a database called evernote_jobs.db. You should exclude these files so that they aren't backed up.
By default the API for the GcmNetworkManager is disabled. In order to use it for pre Lollipop devices you must add the GCM dependency in your build.gradle and then add the service in your AndroidManifest.xml manually.
dependencies {
compile 'com.google.android.gms:play-services-gcm:8.4.0' // or newer
}<service
android:name="com.evernote.android.job.gcm.PlatformGcmService"
android:exported="true"
android:permission="com.google.android.gms.permission.BIND_NETWORK_TASK_SERVICE">
<intent-filter>
<action android:name="com.google.android.gms.gcm.ACTION_TASK_READY"/>
</intent-filter>
</service>The library doesn't use reflection, but it relies on two Services and two BroadcastReceivers. In order to avoid any issues, you shouldn't obfuscate those four classes. The library bundles its own Proguard config and you don't need to do anything, but just in case you can add these rules in your configuration.
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