implementation "androidx.work:work-runtime:2.7.1" //基礎(chǔ)使用
implementation "androidx.work:work-multiprocess:2.7.1" //跨進程時引用

Data data = new Data.Builder().putBoolean("is_test", false).build();
WorkManager.getInstance(this).enqueue(
        new OneTimeWorkRequest.Builder(Test.class) // 執(zhí)行任務(wù)一次性任務(wù)
                .setInputMerger(NewInputMerge.class) // 輸入數(shù)據(jù)合并策略，這里并沒有用，鏈?zhǔn)教幚頃r，多個上流執(zhí)行結(jié)果合并，作為下流輸入數(shù)據(jù)
                .setBackoffCriteria(BackoffPolicy.EXPONENTIAL, 5, TimeUnit.MINUTES) // 重試策略
                .setExpedited(OutOfQuotaPolicy.RUN_AS_NON_EXPEDITED_WORK_REQUEST) // 加急處理
                .addTag("test").addTag("huahua") // 標(biāo)識
                .setInputData(data) // 輸入數(shù)據(jù)
                .setInitialDelay(5, TimeUnit.SECONDS) // 執(zhí)行延時時間
                .setConstraints(new Constraints.Builder().setRequiresBatteryNotLow(true).build()) // 約束，部分約束只對高版本有效
                .build()
);

WorkManager.getInstance(this).enqueue(
        new PeriodicWorkRequest.Builder(Test.class, 2, TimeUnit.HOURS) // 執(zhí)行周期性任務(wù)，周期2小時
                .setBackoffCriteria(BackoffPolicy.EXPONENTIAL, 5, TimeUnit.MINUTES)
                .setExpedited(OutOfQuotaPolicy.RUN_AS_NON_EXPEDITED_WORK_REQUEST)
                .addTag("test").addTag("huahua")
                .setInputData(data)
                .setInitialDelay(5, TimeUnit.SECONDS) // 首次執(zhí)行延時時間
                .setConstraints(new Constraints.Builder().setRequiresBatteryNotLow(true).build())
                .build()
);

WorkManager.getInstance(this).enqueueUniqueWork("test", ExistingWorkPolicy.KEEP,
        new OneTimeWorkRequest.Builder(Test.class).build()); // 此種方法會對重復(fù)名字的任務(wù)進行處理

WorkManager.getInstance(this).getWorkInfosByTagLiveData("test").observe(this, 
        new Observer<List<WorkInfo>>() {
            @Override
            public void onChanged(List<WorkInfo> workInfos) {

            }
        });

public class Test extends Worker {
    public Test(@NonNull Context context, @NonNull WorkerParameters workerParams) {
        super(context, workerParams);
        Data input = getInputData(); // 獲取輸入數(shù)據(jù)
        boolean isTest = input.getBoolean("is_test", true);
    }

    @NonNull
    @Override
    public Result doWork() {
        return Result.success();
    }
}

<string name="androidx_startup" translatable="false">androidx.startup</string>

<provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    android:exported="false"
    tools:node="merge">
    <meta-data
        android:name="androidx.work.WorkManagerInitializer"
        android:value="androidx.startup"
        tools:node="remove" /> // 這表示移除
</provider>

public final class WorkManagerInitializer implements Initializer<WorkManager> {

    private static final String TAG = Logger.tagWithPrefix("WrkMgrInitializer");

    @NonNull
    @Override
    public WorkManager create(@NonNull Context context) {
        Logger.get().debug(TAG, "Initializing WorkManager with default configuration.");
        WorkManager.initialize(context, new Configuration.Builder().build()); // 這里提供Configuration
        return WorkManager.getInstance(context);
    }

    @NonNull
    @Override
    public List<Class<? extends androidx.startup.Initializer<?>>> dependencies() {
        return Collections.emptyList(); // 提供需要執(zhí)行的其它Initializer
    }
}

<provider
        android:name="androidx.startup.InitializationProvider"
        android:authorities="${applicationId}.androidx-startup"
        android:exported="false"
        tools:node="merge" >
        <meta-data
            android:name="androidx.work.WorkManagerInitializer" // 這里為你的實現(xiàn)的Initializer
            android:value="androidx.startup" /> // 這里必須與R.sting.androidx_startup保持一致
    </provider>

void addListener(Runnable listener, Executor executor)

    public boolean set(@Nullable V value) // 正常設(shè)置結(jié)果

    public boolean setException(Throwable throwable) // 執(zhí)行結(jié)果異常

    public boolean setFuture(ListenableFuture<? extends V> future) // 設(shè)置執(zhí)行結(jié)果來源，也就是ListenableFuture的執(zhí)行結(jié)果

Intent.ACTION_DEVICE_STORAGE_OK // 存儲空間夠用
Intent.ACTION_DEVICE_STORAGE_LOW // 存儲空間很低

@Override
public Boolean getInitialState() {
    Intent intent = mAppContext.registerReceiver(null, getIntentFilter());
    if (intent == null || intent.getAction() == null) {
        return true;
    } else {
        switch (intent.getAction()) {
            case Intent.ACTION_DEVICE_STORAGE_OK:
                return true;
            case Intent.ACTION_DEVICE_STORAGE_LOW:
                return false;
            default:
                return null;
        }
    }
}

public void onBroadcastReceive(Context context, @NonNull Intent intent) {
    if (intent.getAction() == null) {
        return;
    }

    switch (intent.getAction()) {
        case Intent.ACTION_DEVICE_STORAGE_OK:
            setState(true);
            break;
        case Intent.ACTION_DEVICE_STORAGE_LOW:
            setState(false);
            break;
    }
}

    public IntentFilter getIntentFilter() {
        IntentFilter intentFilter = new IntentFilter();
        if (Build.VERSION.SDK_INT >= 23) {
            intentFilter.addAction(BatteryManager.ACTION_CHARGING);
            intentFilter.addAction(BatteryManager.ACTION_DISCHARGING);
        } else {
            intentFilter.addAction(Intent.ACTION_POWER_CONNECTED);
            intentFilter.addAction(Intent.ACTION_POWER_DISCONNECTED);
        }
        return intentFilter;
    }

    @Override
    public Boolean getInitialState() {
        IntentFilter intentFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        Intent intent = mAppContext.registerReceiver(null, intentFilter);
        if (intent == null) {
            Logger.get().error(TAG, "getInitialState - null intent received");
            return null;
        }
        return isBatteryChangedIntentCharging(intent);
    }
    
    private boolean isBatteryChangedIntentCharging(Intent intent) {
        boolean charging;
        if (Build.VERSION.SDK_INT >= 23) {
            int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
            charging = (status == BatteryManager.BATTERY_STATUS_CHARGING
                    || status == BatteryManager.BATTERY_STATUS_FULL);
        } else {
            int chargePlug = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0);
            charging = (chargePlug != 0);
        }
        return charging;
    }

@Override
public void onBroadcastReceive(Context context, @NonNull Intent intent) {
    String action = intent.getAction();
    if (action == null) {
        return;
    }
    Logger.get().debug(TAG, String.format("Received %s", action));
    switch (action) {
        case BatteryManager.ACTION_CHARGING:
            setState(true);
            break;
        case BatteryManager.ACTION_DISCHARGING:
            setState(false);
            break;
        case Intent.ACTION_POWER_CONNECTED:
            setState(true);
            break;
        case Intent.ACTION_POWER_DISCONNECTED:
            setState(false);
            break;
    }
}

    Intent.ACTION_BATTERY_OKAY //電量正常
    Intent.ACTION_BATTERY_LOW //電量低

    @Override
    public Boolean getInitialState() {
        IntentFilter intentFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
        Intent intent = mAppContext.registerReceiver(null, intentFilter);
        if (intent == null) {
            Logger.get().error(TAG, "getInitialState - null intent received");
            return null;
        }

        int status = intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1);
        int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
        int scale = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
        float batteryPercentage = level / (float) scale;

        return (status == BatteryManager.BATTERY_STATUS_UNKNOWN
                || batteryPercentage > BATTERY_LOW_THRESHOLD); // 這里是小于15%算是低
    }

    @Override
    public void onBroadcastReceive(Context context, @NonNull Intent intent) {
        if (intent.getAction() == null) {
            return;
        }
        Logger.get().debug(TAG, String.format("Received %s", intent.getAction()));
        switch (intent.getAction()) {
            case Intent.ACTION_BATTERY_OKAY:
                setState(true);
                break;
            case Intent.ACTION_BATTERY_LOW:
                setState(false);
                break;
        }
    }

NetworkState getActiveNetworkState() {
    NetworkInfo info = mConnectivityManager.getActiveNetworkInfo();
    boolean isConnected = info != null && info.isConnected();
    boolean isValidated = isActiveNetworkValidated();
    boolean isMetered = ConnectivityManagerCompat.isActiveNetworkMetered(mConnectivityManager);
    boolean isNotRoaming = info != null && !info.isRoaming();
    return new NetworkState(isConnected, isValidated, isMetered, isNotRoaming);
}          

   public List<Scheduler> createSchedulers(
            @NonNull Context context,
            @NonNull Configuration configuration,
            @NonNull TaskExecutor taskExecutor) {

        return Arrays.asList(
                Schedulers.createBestAvailableBackgroundScheduler(context, this), // 可以被系統(tǒng)喚起調(diào)用手段
                new GreedyScheduler(context, configuration, taskExecutor, this)); // 進程內(nèi)調(diào)用手段
    }

public static void schedule(Configuration configuration,WorkDatabase workDatabase,List<Scheduler> schedulers) {
        if (schedulers == null || schedulers.size() == 0) {
            return;
        }
        WorkSpecDao workSpecDao = workDatabase.workSpecDao();
        List<WorkSpec> eligibleWorkSpecsForLimitedSlots;
        List<WorkSpec> allEligibleWorkSpecs;
        workDatabase.beginTransaction();
        try {
            eligibleWorkSpecsForLimitedSlots = workSpecDao.getEligibleWorkForScheduling(configuration.getMaxSchedulerLimit()); 
            allEligibleWorkSpecs = workSpecDao.getAllEligibleWorkSpecsForScheduling(MAX_GREEDY_SCHEDULER_LIMIT);

            if (eligibleWorkSpecsForLimitedSlots != null && eligibleWorkSpecsForLimitedSlots.size() > 0) {
                long now = System.currentTimeMillis();
                for (WorkSpec workSpec : eligibleWorkSpecsForLimitedSlots) {
                    workSpecDao.markWorkSpecScheduled(workSpec.id, now); // 進行插槽狀態(tài)處理，非默認才會被GreedyScheduler進行調(diào)度
                }
            }
            workDatabase.setTransactionSuccessful();
        } finally {
            workDatabase.endTransaction();
        }

        if (eligibleWorkSpecsForLimitedSlots != null && eligibleWorkSpecsForLimitedSlots.size() > 0) {
            WorkSpec[] eligibleWorkSpecsArray =
                    new WorkSpec[eligibleWorkSpecsForLimitedSlots.size()];
            eligibleWorkSpecsArray =
                    eligibleWorkSpecsForLimitedSlots.toArray(eligibleWorkSpecsArray);
            for (Scheduler scheduler : schedulers) {
                if (scheduler.hasLimitedSchedulingSlots()) {
                    scheduler.schedule(eligibleWorkSpecsArray);
                }
            }
        }

        if (allEligibleWorkSpecs != null && allEligibleWorkSpecs.size() > 0) {
            WorkSpec[] enqueuedWorkSpecsArray = new WorkSpec[allEligibleWorkSpecs.size()];
            enqueuedWorkSpecsArray = allEligibleWorkSpecs.toArray(enqueuedWorkSpecsArray);
            for (Scheduler scheduler : schedulers) {
                if (!scheduler.hasLimitedSchedulingSlots()) {
                    scheduler.schedule(enqueuedWorkSpecsArray);
                }
            }
        }
    }