A 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 or in these slides why you should prefer this library than each separate API. All features from Android Oreo are backward compatible back to Ice Cream Sandwich.
Download the latest version or grab via Gradle:
dependencies {
implementation 'com.evernote:android-job:1.2.6'
// or
implementation 'com.evernote:android-job:1.3.0-alpha06'
}Starting with version 1.3.0 the library will use the WorkManager internally, please read the documentation and opt-in.
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.
You can read the JavaDoc here.
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 recommended to initialize the JobManager in the onCreate() method of your Application object, but there is an alternative, if you don't have access to the Application class.
public class App extends Application {
@Override
public void onCreate() {
super.onCreate();
JobManager.create(this).addJobCreator(new DemoJobCreator());
}
}public class DemoJobCreator implements JobCreator {
@Override
@Nullable
public Job create(@NonNull String tag) {
switch (tag) {
case DemoSyncJob.TAG:
return new DemoSyncJob();
default:
return null;
}
}
}After that you can start scheduling jobs.
public class DemoSyncJob extends Job {
public static final String TAG = "job_demo_tag";
@Override
@NonNull
protected Result onRunJob(Params params) {
// run your job here
return Result.SUCCESS;
}
public static void scheduleJob() {
new JobRequest.Builder(DemoSyncJob.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(DemoSyncJob.TAG)
.setExecutionWindow(30_000L, 40_000L)
.setBackoffCriteria(5_000L, JobRequest.BackoffPolicy.EXPONENTIAL)
.setRequiresCharging(true)
.setRequiresDeviceIdle(false)
.setRequiredNetworkType(JobRequest.NetworkType.CONNECTED)
.setExtras(extras)
.setRequirementsEnforced(true)
.setUpdateCurrent(true)
.build()
.schedule();
}
private void schedulePeriodicJob() {
int jobId = new JobRequest.Builder(DemoSyncJob.TAG)
.setPeriodic(TimeUnit.MINUTES.toMillis(15), TimeUnit.MINUTES.toMillis(5))
.build()
.schedule();
}
private void scheduleExactJob() {
int jobId = new JobRequest.Builder(DemoSyncJob.TAG)
.setExact(20_000L)
.build()
.schedule();
}
private void runJobImmediately() {
int jobId = new JobRequest.Builder(DemoSyncJob.TAG)
.startNow()
.build()
.schedule();
}
private void cancelJob(int jobId) {
JobManager.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
}
}The library doesn't use reflection, but it relies on three 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.
WorkManager is a new architecture component from Google and tries to solve a very similar problem this library tries to solve: implementing background jobs only once for all Android versions. The API is very similar to this library, but provides more features like chaining work items and it runs its own executor.
If you start a new project, you should be using WorkManager instead of this library. You should also start migrating your code from this library to WorkManager. At some point in the future this library will be deprecated.
Starting with version 1.3.0 this library will use the WorkManager internally for scheduling jobs. That should ease the transition to the new architecture component. You only need to add the WorkManager to your classpath, e.g.
dependencies {
implementation "android.arch.work:work-runtime:$work_version"
}This library will detect the WorkManager at runtime and use it from now on. To opt-out of this change (what isn't recommended) either exclude WorkManager from your app or turn the API off with
JobConfig.setApiEnabled(JobApi.WORK_MANAGER, false);The API and feature set of android-job and WorkManager are really similar. However, some features are unique and only supported by one or the other
| Feature | android-job | WorkManager |
|---|---|---|
| Exact jobs | Yes | No |
| Transient jobs | Yes | No |
| Daily jobs | Yes | No |
| Custom Logger | Yes | No |
| Observe job status | No | Yes |
| Chained jobs | No | Yes |
| Work sequences | No | Yes |
This library does not automatically bundle the Google Play Services, because the dependency is really heavy and not all apps want to include them. That's why you need to add the dependency manually, if you want that the library uses the GcmNetworkManager on Android 4, then include the following dependency.
dependencies {
compile "com.google.android.gms:play-services-gcm:latest_version"
}Because of recent changes in the support library, you must turn on the service manually in your AndroidManifest.xml
<service
android:name="com.evernote.android.job.gcm.PlatformGcmService"
android:enabled="true"
tools:replace="android:enabled"/>If you don't turn on the service, the library will always use the AlarmManager on Android 4.x.
Crashes after removing the GCM dependency is a known limitation of the Google Play Services. Please take a look at this workaround to avoid those crashes.
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