JobScheduler – Coding in Flow

[embedyt] https://www.youtube.com/watch?v=3EQWmME-hNA[/embedyt]

Since Android Oreo, idle apps can’t keep background services running anymore. So if you need to do operations even if your app is not running in the foreground, you should use a JobScheduler instead.
In this video we will set up such a JobScheduler by creating a class that extends JobService and then scheduling it with the JOB_SCHEDULER_SERVICE.
In the JobService class, we override onStartJob and onStopJob. In onStartJob we will start a background thread to do some long running (fake) operations. In onStopJob we cancel our work because the system will release the wakelock when the criteria for our job are not met anymore (for example we required an unmetered network and the user disables WiFi). In this case we will reschedule our task to try again later.
When we schedule our job, we pass a JobInfo object to the JobScheduler, which will define under which circumstances we want the system to execute our job. Here we can set criteria like setRequiresDeviceCharging, setRequiredNetworkType, setPeriodic and more. We can even make it survive device reboots with setPersisted.
Lastly we register our JobService in the manifest with the android.permission.BIND_JOB_SERVICE permission and the system will then start our service at the appropriate time, even if our app is not running.

JobInfo.Builder documentation:
developer.android.com/reference/android/app/job/JobInfo.Builder.html

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activity_main.xmlMainActivity.javaExampleJobService.javaAndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical"
    tools:context="com.codinginflow.jobschedulerexample.MainActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="scheduleJob"
        android:text="Schedule Job" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="cancelJob"
        android:text="Cancel Job" />

</LinearLayout>

package com.codinginflow.jobschedulerexample;

import android.app.job.JobInfo;
import android.app.job.JobScheduler;
import android.content.ComponentName;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;

public class MainActivity extends AppCompatActivity {
    private static final String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void scheduleJob(View v) {
        ComponentName componentName = new ComponentName(this, ExampleJobService.class);
        JobInfo info = new JobInfo.Builder(123, componentName)
                .setRequiresCharging(true)
                .setRequiredNetworkType(JobInfo.NETWORK_TYPE_UNMETERED)
                .setPersisted(true)
                .setPeriodic(15 * 60 * 1000)
                .build();

        JobScheduler scheduler = (JobScheduler) getSystemService(JOB_SCHEDULER_SERVICE);
        int resultCode = scheduler.schedule(info);
        if (resultCode == JobScheduler.RESULT_SUCCESS) {
            Log.d(TAG, "Job scheduled");
        } else {
            Log.d(TAG, "Job scheduling failed");
        }
    }

    public void cancelJob(View v) {
        JobScheduler scheduler = (JobScheduler) getSystemService(JOB_SCHEDULER_SERVICE);
        scheduler.cancel(123);
        Log.d(TAG, "Job cancelled");
    }
}

package com.codinginflow.jobschedulerexample;

import android.app.job.JobParameters;
import android.app.job.JobService;
import android.util.Log;


public class ExampleJobService extends JobService {
    private static final String TAG = "ExampleJobService";
    private boolean jobCancelled = false;

    @Override
    public boolean onStartJob(JobParameters params) {
        Log.d(TAG, "Job started");
        doBackgroundWork(params);

        return true;
    }

    private void doBackgroundWork(final JobParameters params) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                for (int i = 0; i < 10; i++) {
                    Log.d(TAG, "run: " + i);
                    if (jobCancelled) {
                        return;
                    }

                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }

                Log.d(TAG, "Job finished");
                jobFinished(params, false);
            }
        }).start();
    }

    @Override
    public boolean onStopJob(JobParameters params) {
        Log.d(TAG, "Job cancelled before completion");
        jobCancelled = true;
        return true;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.codinginflow.jobschedulerexample">

    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

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

</manifest>