對 WorkManager 進行偵錯

如果您發現工作站的執行頻率過高或根本不常執行,以下是一些偵錯步驟,可協助您發現情況。

啟用記錄功能

如要判斷工作站無法正常運作的原因,查看「詳細」 WorkManager 記錄檔會很有幫助。如要啟用記錄功能,請使用自訂初始化功能。

首先,請套用資訊清單合併規則 remove 建立新的 WorkManager 供應商,停用 AndroidManifest.xml 檔案中預設的 WorkManagerInitializer

<provider
    android:name="androidx.work.impl.WorkManagerInitializer"
    android:authorities="${applicationId}.workmanager-init"
    tools:node="remove"/>

現在,預設的 WorkManager 初始化器已停用,您可以使用隨選初始化功能。若要這麼做,android.app.Application 類別必須提供 androidx.work.Configuration.Provider 的實作:

Kotlin

class MyApplication() : Application(), Configuration.Provider {
    override fun getWorkManagerConfiguration() =
        Configuration.Builder()
            .setMinimumLoggingLevel(android.util.Log.DEBUG)
            .build()
}

Java

public class MyApplication extends Application implements Configuration.Provider {
    @NonNull
    @Override
    public Configuration getWorkManagerConfiguration() {
        return new Configuration.Builder()
                .setMinimumLoggingLevel(android.util.Log.DEBUG)
                .build();
    }
}

定義自訂 WorkManager 設定時,系統會在您呼叫 WorkManager.getInstance(Context) (而不是在應用程式啟動時自動) 初始化 WorkManager。詳情請參閱「自訂 WorkManager 設定和初始化」一文,包括 WorkManager 2.1.0 以下版本的支援。

啟用 DEBUG 記錄功能後,您就能透過記錄標記前置字串 WM- 獲得更多記錄檔。

使用 ADB shell dumpsys Jobscheduler

您可以在 Android 6.0 (API 級別 23) 以上版本中使用 adb 取得更多有關工作排程的資訊。如果您是 adb 新手,請參閱「指令列工具」一文瞭解詳情。

安裝 adb 後,請執行下列指令,查看歸因於套件的工作清單:

adb shell dumpsys jobscheduler

輸出內容如下所示:

JOB #u0a172/4: 6412553 com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService
  u0a172 tag=*job*/com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService
  Source: uid=u0a172 user=0 pkg=com.google.android.youtube
  JobInfo:
    Service: com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService
    Requires: charging=false batteryNotLow=false deviceIdle=false
    Extras: mParcelledData.dataSize=180
    Network type: NetworkRequest [ NONE id=0, [ Capabilities: NOT_METERED&INTERNET&NOT_RESTRICTED&TRUSTED&VALIDATED Uid: 10172] ]
    Minimum latency: +1h29m59s687ms
    Backoff: policy=1 initial=+30s0ms
    Has early constraint
  Required constraints: TIMING_DELAY CONNECTIVITY [0x90000000]
  Satisfied constraints: DEVICE_NOT_DOZING BACKGROUND_NOT_RESTRICTED WITHIN_QUOTA [0x3400000]
  Unsatisfied constraints: TIMING_DELAY CONNECTIVITY [0x90000000]
  Tracking: CONNECTIVITY TIME QUOTA
  Implicit constraints:
    readyNotDozing: true
    readyNotRestrictedInBg: true
  Standby bucket: RARE
  Base heartbeat: 0
  Enqueue time: -51m29s853ms
  Run time: earliest=+38m29s834ms, latest=none, original latest=none
  Last run heartbeat: 0
  Ready: false (job=false user=true !pending=true !active=true !backingup=true comp=true)

使用 WorkManager 時,負責管理工作站執行作業的元件在 API 級別 23 以上為 SystemJobService。找出歸因於套件名稱和 androidx.work.impl.background.systemjob.SystemJobService 的工作例項。

每項工作的指令輸出內容都會列出必要、符合和不滿意的限制。檢查工作站的限制是否完全符合要求。

輸出結果也包含最近執行工作的工作記錄,因此您可以利用此記錄,檢查最近是否叫用 SystemJobService

Job history:
     -1h35m26s440ms   START: #u0a107/9008 com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService
     -1h35m26s362ms  STOP-P: #u0a107/9008 com.google.android.youtube/androidx.work.impl.background.systemjob.SystemJobService app called jobFinished

向 WorkManager 2.4.0 以上版本申請診斷資訊

在應用程式的偵錯版本中,您可以使用下列指令,向 WorkManager 2.4.0 以上版本要求診斷資訊:

adb shell am broadcast -a "androidx.work.diagnostics.REQUEST_DIAGNOSTICS" -p "<your_app_package_name>"

提供下列資訊:

  • 過去 24 小時內完成的工作要求。
  • 目前正在執行的作業要求。
  • 已排定的工作要求。

其外觀可能如下 (輸出內容會顯示在 logcat 中):

adb shell am broadcast -a "androidx.work.diagnostics.REQUEST_DIAGNOSTICS" -p "androidx.work.integration.testapp"

adb logcat
...
2020-02-13 14:21:37.990 29528-29660/androidx.work.integration.testapp I/WM-DiagnosticsWrkr: Recently completed work:
2020-02-13 14:21:38.083 29528-29660/androidx.work.integration.testapp I/WM-DiagnosticsWrkr: Id  Class Name   State  Unique Name Tags
    08be261c-2def-4bd6-a716-1e4410968dc4     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    48ce04f1-8df9-450b-96ec-6eceabb9c690     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    c46f4699-c384-440c-a10e-26d56ce02963     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    ce125372-046e-484e-949f-9abb35ce62c3     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    72887ddd-8ed1-4018-b798-fac218e95e16     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    dcff3d61-320d-4996-8644-5d97944bd09c     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    acab0bf7-6087-43ad-bdb5-be0df9195acb     androidx.work.impl.workers.DiagnosticsWorker    SUCCEEDED  null    androidx.work.impl.workers.DiagnosticsWorker
    23136bcd-01dd-46eb-b910-0fe8a140c2a4     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    245f4879-c6d2-4997-8130-e4e90e1cab4c     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    17d05835-bb61-429a-ad11-fe43fc320a54     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    e95f12be-4b0c-4e64-88da-8ee07a31e42f     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    431c3ec2-4a55-469b-b50b-4072d35f1232     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    883a388f-f911-4098-9143-37bd8fbc098a     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    b904163c-6822-4299-8d5a-78df49b7e53d     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
    453fd7b9-2b16-45b9-abc5-3d2ce7b6a4ba     androidx.work.integration.testapp.ToastWorker   SUCCEEDED  null    androidx.work.integration.testapp.ToastWorker
2020-02-13 14:21:38.083 29528-29660/androidx.work.integration.testapp I/WM-DiagnosticsWrkr: Running work:
2020-02-13 14:21:38.089 29528-29660/androidx.work.integration.testapp I/WM-DiagnosticsWrkr: Id  Class Name   State  Unique Name Tags
    b87c8a4f-4ac6-4e25-ba3e-4cea53ce468a     androidx.work.impl.workers.DiagnosticsWorker    RUNNING    null    androidx.work.impl.workers.DiagnosticsWorker
...