簡單學習
最新庫的版本以及更新日志
https://developer.android.google.cn/jetpack/androidx/releases/work?hl=zh-cn
首先導入庫
下邊的庫看自己需求添加，并非所有的都需要，比如java和kotlin兩種
dependencies {
def work_version = "2.2.0"
// (Java only)
implementation "androidx.work:work-runtime:$work_version"
// Kotlin + coroutines
implementation "androidx.work:work-runtime-ktx:$work_version"
// optional - RxJava2 support
implementation "androidx.work:work-rxjava2:$work_version"
// optional - GCMNetworkManager support
implementation "androidx.work:work-gcm:$work_version"
// optional - Test helpers
androidTestImplementation "androidx.work:work-testing:$work_version"
}
創建任務
繼承Worker類，實現doWork方法，doWork() 方法在 WorkManager 提供的后臺線程上同步運行
public class UploadWorker extends Worker {
public UploadWorker(
@NonNull Context context,
@NonNull WorkerParameters params) {
super(context, params);
}
@Override
public Result doWork() {
// Do the work here--in this case, upload the images.
uploadImages()
// Indicate whether the task finished successfully with the Result
return Result.success()
}
}
已成功完成：Result.success()
已失敗：Result.failure()
需要稍后重試：Result.retry()
成功和失敗，還可以傳個Data數據，給下一個worker或者自己接收
val data = Data.Builder().apply {
//可以put一些基礎數據類型
putString("key", "from My Worker");
}.build()
簡單介紹下幾種任務
- Worker
public abstract class Worker extends ListenableWorker
- CoroutineWorker [kotlin下用的]
abstract class CoroutineWorker(
appContext: Context,
params: WorkerParameters
) : ListenableWorker(appContext, params)
配置運行任務的方式和時間
worker弄好了，我們還要確定任務執行的方式，是一次性的，還是重復性的，系統也提供了對應的類
OneTimeWorkRequest uploadWorkRequest = new OneTimeWorkRequest.Builder(UploadWorker.class)
.build()
代碼簡單的寫了這兩種任務的實例
//任務運行的一些條件設置
var constraints=Constraints.Builder()
.setRequiredNetworkType(NetworkType.CONNECTED)
.setRequiresBatteryNotLow(false)
.setRequiresCharging(false)
.setRequiresDeviceIdle(false)
.setTriggerContentMaxDelay(10,TimeUnit.MINUTES)
.setTriggerContentUpdateDelay(10,TimeUnit.SECONDS)
.build()
//這個數據在Worker里可以通過getInputData（）方法拿到
var input=Data.Builder()
.putString("url","www.xxx.xxx")
.putInt("retry",3)
.build()
var request= OneTimeWorkRequest.Builder(MyWoker::class.java)
.addTag("xxx")
.setConstraints(constraints)
.setInitialDelay(10,TimeUnit.SECONDS)
.setInputData(input)
.build()
var request2=PeriodicWorkRequest.Builder(MyWoker::class.java, 10,TimeUnit.MINUTES)
.setConstraints(constraints)
.setInitialDelay(10,TimeUnit.SECONDS)
.setInputData(input)
.build()
kotlin版本的
request= OneTimeWorkRequestBuilder<MyWoker>()
.setConstraints(constraints)
.setInitialDelay(10,TimeUnit.SECONDS)
.setInputData(input)
.build()
request2= PeriodicWorkRequestBuilder<MyWoker>(10,TimeUnit.MINUTES)
.setConstraints(constraints)
.setInitialDelay(10,TimeUnit.SECONDS)
.setInputData(input)
.build()
其他：
PeriodicWorkRequest的Builder還有一種構造方法，可以傳入flex時間，不傳的默認和repeat interval時間一樣
public Builder(
@NonNull Class<? extends ListenableWorker> workerClass,
long repeatInterval,
@NonNull TimeUnit repeatIntervalTimeUnit,
long flexInterval,
@NonNull TimeUnit flexIntervalTimeUnit)
這個時間有啥用，看下文檔
就是說你repeat時間是15分鐘，flex時間是5分鐘，那么其實就相當于每次延遲5分鐘執行任務，當然不是5分鐘以后立馬執行，worker這東西時間不是確定的，它是在這個時間段執行
Note that flex intervals are ignored for certain OS versions (in particular, API 23).
//23的設備，這個字段無效
* <p><pre>
* [ before flex | flex ][ before flex | flex ]...
* [ cannot run work | can run work ][ cannot run work | can run work ]...
* \____________________________________/\____________________________________/...
* interval 1 interval 2 ...(repeat)
間隔任務時間是有限制的,你設置比這個小沒用，它會自動改成這個最小值
/**
* The minimum interval duration for {@link PeriodicWorkRequest} (in milliseconds).
*/
public static final long MIN_PERIODIC_INTERVAL_MILLIS = 15 * 60 * 1000L; // 15 minutes.
/**
* The minimum flex duration for {@link PeriodicWorkRequest} (in milliseconds).
*/
public static final long MIN_PERIODIC_FLEX_MILLIS = 5 * 60 * 1000L; // 5 minutes.
開始執行任務
上邊request也有了，worker也有了，那么現在讓request開始處理worker吧
首先獲取WorkManager的實例，以前沒有context參數，還得手動init，現在不用了，傳個context，會自己判斷有沒有init來生成對應的實例
WorkManager.getInstance(applicationContext)
執行,有beginWith,then,enqueue操作
WorkManager.getInstance(applicationContext).beginWith(request).then(request3).then(request).enqueue()
WorkManager.getInstance(applicationContext).enqueue(arrayListOf(request,request3,request2))
beginWith,then只能執行一次性的任務
enqueue啥任務都行
參數可以是單個任務，也可以是多個任務【集合】
public final @NonNull WorkContinuation beginWith(@NonNull OneTimeWorkRequest work)
public abstract @NonNull WorkContinuation beginWith(@NonNull List<OneTimeWorkRequest> work)
public final Operation enqueue(@NonNull WorkRequest workRequest)
public abstract Operation enqueue(@NonNull List<? extends WorkRequest> requests)
public final @NonNull WorkContinuation then(@NonNull OneTimeWorkRequest work)
public abstract @NonNull WorkContinuation then(@NonNull List<OneTimeWorkRequest> work)
public abstract @NonNull Operation enqueue();
上邊的這些還有另外一種UniqueWork
顧名思義，就是對于uniqueWorkName一樣的任務只能有一個，那已經有咋辦，由第二個參數來決定
public abstract @NonNull WorkContinuation beginUniqueWork(
@NonNull String uniqueWorkName,
@NonNull ExistingWorkPolicy existingWorkPolicy,
@NonNull List<OneTimeWorkRequest> work)
3個看名字大概就知道啥意思了，如果沒有存在的同名任務，那么添加一個新的，這時候這個參數無意義，大家都一樣
replace：有老的，把老的取消刪除
keep：有老的，就繼續老的，新的其實就等于沒用到
append：就是把現有的任務 添加到老的任務下邊，您不能將 APPEND 與 PeriodicWorkRequest 一起使用。
public enum ExistingWorkPolicy {
/**
* If there is existing pending (uncompleted) work with the same unique name, cancel and delete
* it. Then, insert the newly-specified work.
*/
REPLACE,
/**
* If there is existing pending (uncompleted) work with the same unique name, do nothing.
* Otherwise, insert the newly-specified work.
*/
KEEP,
/**
* If there is existing pending (uncompleted) work with the same unique name, append the
* newly-specified work as a child of all the leaves of that work sequence. Otherwise, insert
* the newly-specified work as the start of a new sequence.
*/
APPEND
}
取消任務
tag 可以在workerRequest里設置，上邊有
uuid 可以通過workerRequest ，getId拿到
至于uniqueWork對應上邊的uniqueWork
image.png
查看任務的狀態
下邊是方法，先拿到你要找的任務
WorkManager.getInstance(applicationContext).getWorkInfosByTag("xxx").get()[0].state
image.png
public enum State {
/**
* Used to indicate that the {@link WorkRequest} is enqueued and eligible to run when its
* {@link Constraints} are met and resources are available.
*/
ENQUEUED,
/**
* Used to indicate that the {@link WorkRequest} is currently being executed.
*/
RUNNING,
/**
* Used to indicate that the {@link WorkRequest} has completed in a successful state. Note
* that {@link PeriodicWorkRequest}s will never enter this state (they will simply go back
* to {@link #ENQUEUED} and be eligible to run again).
*/
SUCCEEDED,
/**
* Used to indicate that the {@link WorkRequest} has completed in a failure state. All
* dependent work will also be marked as {@code #FAILED} and will never run.
*/
FAILED,
/**
* Used to indicate that the {@link WorkRequest} is currently blocked because its
* prerequisites haven't finished successfully.
*/
BLOCKED,
/**
* Used to indicate that the {@link WorkRequest} has been cancelled and will not execute.
* All dependent work will also be marked as {@code #CANCELLED} and will not run.
*/
CANCELLED;
/**
* Returns {@code true} if this State is considered finished.
*
* @return {@code true} for {@link #SUCCEEDED}, {@link #FAILED}, and * {@link #CANCELLED}
* states
*/
public boolean isFinished() {
return (this == SUCCEEDED || this == FAILED || this == CANCELLED);
}
}
刪除完成的任務
包括，success，failed，cancelled
- Is finished (succeeded, failed, or cancelled)
- Has zero unfinished dependents
這些任務其實是寫在用room庫處理的數據庫里的，就算worker執行完，任務信息也不會立馬刪除，還是在數據庫了，只是狀態變了而已，當然系統過一段時間會清理掉這些完成的任務的，具體多久不清楚
我們也可以手動刪除已完成的任務，
workManager.pruneWork()
點擊參考 源碼研究
worker state 查看
進度設置，WorkManager 2.3.0-alpha01以上才有的
鏈接工作
比如,先有3個任務filter1,2,3,都一起做完了以后把結果告訴下個工作compress，現在看下compress咋獲取到數據
WorkManager.getInstance(myContext)
// Candidates to run in parallel
.beginWith(Arrays.asList(filter1, filter2, filter3))
// Dependent work (only runs after all previous work in chain)
.then(compress)
.then(upload)
// Don't forget to enqueue()
.enqueue();
首先我們知道一個worker做完，可以在結果了插入數據
val output=Data.Builder().putString("path","out put data").build()
return Result.success(output)
如果filter1,2,3是同一個worker，output里的key都一樣，那咋拿到這些value？
這里可以用到InputMerger，對output里的數據進行處理
WorkManager 提供兩種不同類型的 InputMerger：
-
OverwritingInputMerger會嘗試將所有輸入中的所有鍵添加到輸出中。如果發生沖突，它會覆蓋先前設置的鍵。
舉個例子：filter 返回的key都是path，那么compress里最后收到的只有一個path，就是最后執行的那個filter傳出來的 -
ArrayCreatingInputMerger會嘗試合并輸入，并在必要時創建數組
這種把value封裝成一個集合了，可以去看下源碼，比較簡單，比如你是string，設置這個以后，在compress任務里拿到的value就是個stringArray了
OneTimeWorkRequestBuilder<CompressWorker>().setInputMerger(ArrayCreatingInputMerger::class.java).build()
//設置了inputMerger為ArrayCreatingInputMerger以后，數據就封裝成集合了
val input=inputData;
val path=input.getStringArray("path")
默認不設置的話，就是OverwritingInputMerger，也就是key一樣的，后邊的數據會覆蓋前邊的
創建 OneTimeWorkRequest 鏈時，需要注意以下幾點：
從屬 OneTimeWorkRequest 僅在其所有父級 OneTimeWorkRequest 都成功完成（即返回 Result.success()）時才會被解除阻塞（變為 ENQUEUED 狀態）。
如果有任何父級 OneTimeWorkRequest 失敗（返回 Result.failure()），則所有從屬 OneTimeWorkRequest 也會被標記為 FAILED。
如果有任何父級 OneTimeWorkRequest 被取消，則所有從屬 OneTimeWorkRequest 也會被標記為 CANCELLED
image.png
自定義 WorkManager 配置和初始化
前邊講過，新版庫默認init了workerManager
public class WorkManagerInitializer extends ContentProvider {
@Override
public boolean onCreate() {
// Initialize WorkManager with the default configuration.
WorkManager.initialize(getContext(), new Configuration.Builder().build());
return true;
}
如果不滿意，可以刪掉，然后自己重寫
先刪掉這個ContentProvider
<provider
android:name="androidx.work.impl.WorkManagerInitializer"
android:authorities="${applicationId}.workmanager-init"
tools:node="remove" />
然后在application里繼承Configuration.Provider，寫自己的Configuration
class MyApplication extends Application implements Configuration.Provider {
@Override
public Configuration getWorkManagerConfiguration() {
return Configuration.Builder()
.setMinimumLoggingLevel(android.util.Log.INFO)
.build();
}
}
//下邊是Configuration的屬性，都可以通過builder里修改
public static final class Builder {
Executor mExecutor;
WorkerFactory mWorkerFactory;
Executor mTaskExecutor;
int mLoggingLevel = Log.INFO;
int mMinJobSchedulerId = IdGenerator.INITIAL_ID;
int mMaxJobSchedulerId = Integer.MAX_VALUE;
int mMaxSchedulerLimit = MIN_SCHEDULER_LIMIT;
然后看下下圖，我們取消自動初始化以后，在application里實現Provider，這里就用到了
image.png
補充
- 如何停止worker
，比如下邊你在執行一個循環任務的時候，可以加個條件，判斷是否isStopped來決定任務是否繼續下去
public Result doWork() {
for (int i = 0; i < 100; ++i) {
if (isStopped()) {
break;
}
try {
downloadSynchronously("https://www.google.com");
} catch (IOException e) {
return Result.failure();
}
}
return Result.success();
}
- kotlin下的CoroutineWorker 取消任務
CoroutineWorker 通過取消協程并傳播取消信號來自動處理停工情況。您無需執行任何特殊操作來處理停工任務
class CoroutineDownloadWorker(context: Context, params: WorkerParameters) : CoroutineWorker(context, params) {
override val coroutineContext = Dispatchers.IO
override suspend fun doWork(): Result = coroutineScope {
val jobs = (0 until 100).map {
async {
downloadSynchronously("https://www.google.com")
}
}
// awaitAll will throw an exception if a download fails, which CoroutineWorker will treat as a failure
jobs.awaitAll()
Result.success()
}
}
- Constraints.Builder().setRequiresCharging(false) 這個boolean值的作用
，如果設置為true，那么必須插上電源這個任務才會運行。 這里插上電源，我試了下，必須是交流電。用數據線連接到電腦上的不算。
begin(a).then(b)的效果，a執行完，并且dowork（）返回WorkerResult.SUCCESS ，b才會執行。
如果a返回了FAILED,那么b不會執行的，如果a返回retry，那么a就會等待時機再次嘗試，直到返回成功，b才會執行。
測試中發現。點開start以后，我就打開應用程序，點了強制停止，然后發現過了一會它又成了運行狀態了【強制停止不是灰色的，又可以點擊了】
而且studio的日志里看到下邊的東西
22:44:17.247 : Failed execv(/system/bin/dex2oat --runtime-arg -classpath --runtime-arg --debuggable --instruction-set=arm --instruction-set-features=smp,-div,-atomic_ldrd_strd --runtime-arg -Xrelocate --boot-image=/system/framework/boot.art --runtime-arg -Xms64m --runtime-arg -Xmx512m --instruction-set-variant=cortex-a53 --instruction-set-features=default --dex-file=/data/app/com.charliesong.demo0327-1/split_lib_dependencies_apk.apk --oat-file=/data/dalvik-cache/arm/data@app@com.charliesong.demo0327-1@split_lib_dependencies_apk.apk@classes.dex) because non-0 exit status
22:44:18.887 D/PackageManagerHelper: androidx.work.impl.background.systemjob.SystemJobService enabled
22:44:18.887 D/Schedulers: Created SystemJobScheduler and enabled SystemJobService
22:44:18.897 D/PackageManagerHelper: androidx.work.impl.background.firebase.FirebaseJobService could not be disabled
java.lang.IllegalArgumentException: Component class androidx.work.impl.background.firebase.FirebaseJobService does not exist in com.charliesong.demo0327
22:44:18.897 D/PackageManagerHelper: androidx.work.impl.background.systemalarm.SystemAlarmService disabled
22:44:18.907 I/InstantRun: starting instant run server: is main process
22:44:18.907 D/ForceStopRunnable: Application was force-stopped, rescheduling.
22:44:18.987 D/SystemJobService: onStartJob for c4d275cb-10af-4c08-bc9b-0985f196cbd9
22:44:18.987 D/SystemJobScheduler: Scheduling work ID c4d275cb-10af-4c08-bc9b-0985f196cbd9 Job ID 40
22:44:18.987 D/SystemJobService: Job is already being executed by SystemJobService: c4d275cb-10af-4c08-bc9b-0985f196cbd9
22:44:18.997 D/SystemJobScheduler: Scheduling work ID c4d275cb-10af-4c08-bc9b-0985f196cbd9 Job ID 41
22:44:18.997 D/SystemJobScheduler: Scheduling work ID ce1865ad-3d30-4e0d-8474-f6d64307a973 Job ID 42
22:44:18.997 /SystemJobScheduler: Scheduling work ID ce1865ad-3d30-4e0d-8474-f6d64307a973 Job ID 43
22:44:18.997 D/Processor: Processor: processing c4d275cb-10af-4c08-bc9b-0985f196cbd9
22:44:19.017 D/WorkerWrapper: Worker result SUCCESS for c4d275cb-10af-4c08-bc9b-0985f196cbd9
22:44:19.027 D/Processor: Processor c4d275cb-10af-4c08-bc9b-0985f196cbd9 executed; isSuccessful = true, reschedule = false
22:44:19.027 D/SystemJobService: c4d275cb-10af-4c08-bc9b-0985f196cbd9 executed on JobScheduler
22:44:19.027 /SystemJobScheduler: Scheduling work ID ce1865ad-3d30-4e0d-8474-f6d64307a973 Job ID 44
22:44:19.037 /SystemJobScheduler: Scheduling work ID ce1865ad-3d30-4e0d-8474-f6d64307a973 Job ID 45
22:44:39.017 /SystemJobService: onStartJob for c4d275cb-10af-4c08-bc9b-0985f196cbd9
22:44:39.017 /SystemJobService: Job is already being executed by SystemJobService: c4d275cb-10af-4c08-bc9b-0985f196cbd9
22:44:39.017 /Processor: Processor: processing c4d275cb-10af-4c08-bc9b-0985f196cbd9
22:44:39.027 com.charliesong.demo0327 E/WorkerWrapper: Status for c4d275cb-10af-4c08-bc9b-0985f196cbd9 is SUCCEEDED; not doing any work
22:44:39.027 /Processor: Processor c4d275cb-10af-4c08-bc9b-0985f196cbd9 executed; isSuccessful = false, reschedule = false
22:44:39.027 /SystemJobService: c4d275cb-10af-4c08-bc9b-0985f196cbd9 executed on JobScheduler
22:44:48.087 /SystemJobService: onStartJob for ce1865ad-3d30-4e0d-8474-f6d64307a973
22:44:48.087 /Processor: Processor: processing ce1865ad-3d30-4e0d-8474-f6d64307a973
22:44:48.087 /SystemJobService: Job is already being executed by SystemJobService: ce1865ad-3d30-4e0d-8474-f6d64307a973
22:44:48.107 /WorkerWrapper: Worker result SUCCESS for ce1865ad-3d30-4e0d-8474-f6d64307a973
22:44:48.117 /WorkerWrapper: Setting status to enqueued for 95339398-f24f-439f-aab0-3dfbbe787d45
22:44:48.117 /Processor: Processor ce1865ad-3d30-4e0d-8474-f6d64307a973 executed; isSuccessful = true, reschedule = false
22:44:48.117 /SystemJobService: ce1865ad-3d30-4e0d-8474-f6d64307a973 executed on JobScheduler
22:44:48.127 /SystemJobScheduler: Scheduling work ID 95339398-f24f-439f-aab0-3dfbbe787d45 Job ID 46
22:44:48.127 /SystemJobScheduler: Scheduling work ID 95339398-f24f-439f-aab0-3dfbbe787d45 Job ID 47
22:45:09.017 /SystemJobService: onStartJob for ce1865ad-3d30-4e0d-8474-f6d64307a973
22:45:09.017 /Processor: Processor: processing ce1865ad-3d30-4e0d-8474-f6d64307a973
22:45:09.017 /SystemJobService: Job is already being executed by SystemJobService: ce1865ad-3d30-4e0d-8474-f6d64307a973
22:45:09.027 com.charliesong.demo0327 E/WorkerWrapper: Status for ce1865ad-3d30-4e0d-8474-f6d64307a973 is SUCCEEDED; not doing any work
22:45:09.027 /Processor: Processor ce1865ad-3d30-4e0d-8474-f6d64307a973 executed; isSuccessful = false, reschedule = false
22:45:09.027 /SystemJobService: ce1865ad-3d30-4e0d-8474-f6d64307a973 executed on JobScheduler
22:45:10.017 /SystemJobService: onStartJob for ce1865ad-3d30-4e0d-8474-f6d64307a973
22:45:10.017 /Processor: Processor: processing ce1865ad-3d30-4e0d-8474-f6d64307a973
22:45:10.017 /SystemJobService: Job is already being executed by SystemJobService: ce1865ad-3d30-4e0d-8474-f6d64307a973
22:45:10.027 com.charliesong.demo0327 E/WorkerWrapper: Status for ce1865ad-3d30-4e0d-8474-f6d64307a973 is SUCCEEDED; not doing any work
22:45:10.027 /Processor: Processor ce1865ad-3d30-4e0d-8474-f6d64307a973 executed; isSuccessful = false, reschedule = false
22:45:10.027 /SystemJobService: ce1865ad-3d30-4e0d-8474-f6d64307a973 executed on JobScheduler
22:45:58.907 /SystemJobService: onStartJob for 95339398-f24f-439f-aab0-3dfbbe787d45
22:45:58.907 /Processor: Processor: processing 95339398-f24f-439f-aab0-3dfbbe787d45
22:45:58.917 /SystemJobService: Job is already being executed by SystemJobService: 95339398-f24f-439f-aab0-3dfbbe787d45
22:45:58.927 /WorkerWrapper: Worker result SUCCESS for 95339398-f24f-439f-aab0-3dfbbe787d45
22:45:58.927 /Processor: Processor 95339398-f24f-439f-aab0-3dfbbe787d45 executed; isSuccessful = true, reschedule = false
22:45:58.927 /SystemJobService: 95339398-f24f-439f-aab0-3dfbbe787d45 executed on JobScheduler
另外當start執行了N次以后，可以看到get到的也是N次的信息,除非卸載重裝，否則start了n次tag為xxx的work，到時候getbytag就能獲取N次
06-10 22:53:50.047 com.charliesong.demo0327 I/System.out: 0==============2140871e-f14a-498e-bc41-e6728b91a7ae====SUCCEEDED//true==[work1]
06-10 22:53:50.047 com.charliesong.demo0327 I/System.out: 1==============85ed6feb-b5d2-4c5b-a3c6-c005ea60054e====SUCCEEDED//true==[work1]
06-10 22:53:50.047 com.charliesong.demo0327 I/System.out: 2==============87b3b5d9-000d-4ef2-ba7e-2c005fc29da8====SUCCEEDED//true==[work1]
06-10 22:53:50.047 com.charliesong.demo0327 I/System.out: 3==============c4d275cb-10af-4c08-bc9b-0985f196cbd9====SUCCEEDED//true==[work1]
不過有點奇怪的是，我start里就有3個任務，可每次都有4條日志,前2條的work ID是一樣的，就是job ID 不一樣，不懂。
06-10 22:59:49.737 xxx D/SystemJobScheduler: Scheduling work ID bbef65fb-aca0-4b8f-96a1-50da7234e5c8 Job ID 8
06-10 22:59:49.737 xxx D/SystemJobScheduler: Scheduling work ID bbef65fb-aca0-4b8f-96a1-50da7234e5c8 Job ID 9
06-10 22:59:49.737 xxxx D/SystemJobScheduler: Scheduling work ID cb3f7b83-9b8b-4e8d-aeb3-915d2498ff3f Job ID 10
06-10 22:59:49.737 xxx D/SystemJobScheduler: Scheduling work ID cb3f7b83-9b8b-4e8d-aeb3-915d2498ff3f Job ID 11
測試
卸載重裝app，然后開啟一個任務
val oneTimeRequest= OneTimeWorkRequestBuilder<Worker2>().setConstraints(constraints).setInputData(data)
.addTag("worker2")
.build()
WorkManager.getInstance().beginWith(oneTimeRequest).enqueue()
class Worker2:Worker() {
override fun doWork(): WorkerResult {
println("start ${javaClass.simpleName}==================")
Thread.sleep(3000)
println("end ${javaClass.simpleName}================")
val date=SimpleDateFormat("yyyyMMDD_HHmmss", Locale.getDefault()).format(Date())
UtilFile.saveStringToTempFile("$date ${javaClass.simpleName} ${inputData.getString("title","")} \r\n")
return WorkerResult.SUCCESS
}
}
日志
21:18:45.793 D/SystemJobScheduler: Scheduling work ID 17d724d0-757e-44e3-8814-1b7a933a3f46 Job ID 0
21:18:45.793 D/SystemJobScheduler: Scheduling work ID 17d724d0-757e-44e3-8814-1b7a933a3f46 Job ID 1
21:18:45.793 D/GreedyScheduler: Starting tracking for 17d724d0-757e-44e3-8814-1b7a933a3f46
D/ConstraintTracker: NetworkStateTracker: initial state = [ Connected=true Validated=true Metered=false NotRoaming=true ]
21:18:45.803 D/NetworkStateTracker: Registering broadcast receiver
21:18:45.803 D/WorkConstraintsTracker: Constraints met for 17d724d0-757e-44e3-8814-1b7a933a3f46
21:18:45.803 D/GreedyScheduler: Constraints met: Scheduling work ID 17d724d0-757e-44e3-8814-1b7a933a3f46
21:18:45.803 D/WorkConstraintsTracker: Constraints met for 17d724d0-757e-44e3-8814-1b7a933a3f46
21:18:45.803 D/GreedyScheduler: Constraints met: Scheduling work ID 17d724d0-757e-44e3-8814-1b7a933a3f46
21:18:45.813 D/Processor: Processor: processing 17d724d0-757e-44e3-8814-1b7a933a3f46
21:18:45.813 D/Processor: Work 17d724d0-757e-44e3-8814-1b7a933a3f46 is already enqueued for processing
I/System.out: start Worker2==================
21:18:45.873 D/ViewRootImpl: MSG_RESIZED_REPORT: ci=Rect(0, 24 - 0, 0) vi=Rect(0, 0 - 0, 0) or=2
21:18:45.883 D/NetworkStateTracker: Network broadcast received
21:18:45.923 I/Timeline: Timeline: Activity_idle id: android.os.BinderProxy@caf4359 time:15813324
21:18:46.803 D/SystemJobService: onStartJob for 17d724d0-757e-44e3-8814-1b7a933a3f46
21:18:46.803 D/Processor: Work 17d724d0-757e-44e3-8814-1b7a933a3f46 is already enqueued for processing
21:18:46.803 D/SystemJobService: Job is already being executed by SystemJobService: 17d724d0-757e-44e3-8814-1b7a933a3f46
21:18:48.843 I/System.out: end Worker2================
21:18:48.843 D/WorkerWrapper: Worker result SUCCESS for 17d724d0-757e-44e3-8814-1b7a933a3f46
21:18:48.853 D/Processor: Processor 17d724d0-757e-44e3-8814-1b7a933a3f46 executed; isSuccessful = true, reschedule = false
21:18:48.853 D/SystemJobService: 17d724d0-757e-44e3-8814-1b7a933a3f46 executed on JobScheduler
間隔時間重復執行某個work
看文章發現有個PeriodicWorkRequest可以執行重復的任務，試了下結果發現沒重復啊，后來點擊源碼才看到，這玩意默認的最小間隔是15分鐘。
fun startRepeateWork(){
var request=PeriodicWorkRequest.Builder(MyWorker::class.java,1,TimeUnit.MINUTES).addTag("hello").build()
WorkManager.getInstance().enqueue(request)
UtilNormal.saveUUID(this,request.id.toString())
}
fun getRepeatWorkStatus(){
var str=UtilNormal.getUUID(this)
if(TextUtils.isEmpty(str)){
return
}
WorkManager.getInstance().getStatusById(UUID.fromString(str))?.apply {
this.removeObserver(observerOnly)
this.observeForever(observerOnly)
}
}
val observerOnly=object:Observer<WorkStatus>{
override fun onChanged(t: WorkStatus?) {
t?.apply {
println("onChanged==============${t.id}====${t.state}//${t.state.isFinished}==${t.tags}")
}
}
}
今天在一個新項目里添加這個room庫的時候，編譯的時候掛了，說有重復的庫
Error: Program type already present: android.support.v4.app.INotificationSideChannel
解決辦法
在gradle.properties文件下添加
android.useAndroidX=true
android.enableJetifier=true
然后點擊下邊按鈕，遷移為androidX庫，完事就沒問題了。
image.png
然后寫了個任務，等到執行的時候總是掛
public class AutoPlayWork extends Worker{
public AutoPlayWork(@NonNull Context context, @NonNull WorkerParameters workerParams) {
super(context, workerParams);
}
@NonNull
@Override
public Result doWork() {
//xxxx
return Result.success();
}
異常如下
WM-WorkerFactory: Could not instantiate com.mitac.lockdown.util.ScheduleTaskManager$AutoPlayWork
java.lang.NoSuchMethodException: <init> [class android.content.Context, class androidx.work.WorkerParameters]
at java.lang.Class.getConstructor(Class.java:528)
at java.lang.Class.getDeclaredConstructor(Class.java:507)
at androidx.work.WorkerFactory.createWorkerWithDefaultFallback(WorkerFactory.java:91)
點進去看下,也就是newInstance通過構造方法實例化一個對象失敗了，無語
try {
Constructor<? extends ListenableWorker> constructor =
clazz.getDeclaredConstructor(Context.class, WorkerParameters.class);
worker = constructor.newInstance(
appContext,
workerParameters);
return worker;
} catch (Exception e) {
Logger.get().error(TAG, "Could not instantiate " + workerClassName, e);
}
解決辦法：
首先出錯原因，這個work類我是寫在工具里里的，也即是說是個內部類，實例化的時候需要外部類的對象才行的，這個肯定沒有的啊。
所以把這個類設置成靜態的，或者把這個類拉到外邊單獨寫
強制關閉前臺其他應用
需要系統權限，我們的app就是系統級應用，所以可用，否則就需要root了，然后執行adb命令，這個網上有
//需要權限：
android:sharedUserId="android.uid.system"
<uses-permission android:name="android.permission.FOCE_STOP_PACKAGES" />
ActivityManager activityManager = (ActivityManager)getSystemService(Context.ACTIVITY_SERVICE);
activityManager.forceStopPackage("com.android.scan");
注意
對于這種重復的任務,這種任務你如果不手動取消的話，那么任務會一直重復下去，即使app被殺死，下次啟動任務還在的。
你如果每次打開app都執行下邊的代碼，那么你的app里就會有多個這樣的重復任務了。
很明顯不合理，所以
你需要每次執行前，先cancel掉舊的worker，
或者這個執行完做個本地標記，下次執行前先判斷下有沒有執行過
var request=PeriodicWorkRequest.Builder(MyWorker::class.java,1,TimeUnit.MINUTES).addTag("hello").build()
WorkManager.getInstance().enqueue(request)
可以通過worker的tag來找到對應的任務取消
getWorkInfosByTag(MyWorker::class.java.name)
WorkManager.getInstance(this).cancelAllWorkByTag(MyWorker::class.java.name)
