Android Gradle 构建插件 4.0.0 和 R8 脱糖在 API 19 上不起作用
Android Gradle Build Plugin 4.0.0 & R8 Desugaring not working on API 19
我正在将 Android 应用程序从使用 Proguard 的脱糖转换为 Android Gradle 构建插件 4.0.0 中提供的新 R8 脱糖。
我已按照 in the official documentation 中详细说明的步骤启用 Java 8 库脱糖：
gradle.properties
projectJavaVersion = 1.8
android.useAndroidX=true
android.enableJetifier=true
应用build.gradle
plugins {
id 'com.android.application'
id 'kotlin-android'
}
android {
buildToolsVersion '29.0.2'
compileSdkVersion 29
compileOptions {
coreLibraryDesugaringEnabled true
sourceCompatibility projectJavaVersion
targetCompatibility projectJavaVersion
}
kotlinOptions {
jvmTarget = projectJavaVersion
}
defaultConfig {
multiDexEnabled true
minSdkVersion 19
targetSdkVersion 23
applicationId = 'com.example.app'
}
buildTypes {
release {
...
minifyEnabled true
}
debug {
debuggable true
minifyEnabled true
}
}
}
dependencies {
coreLibraryDesugaring "com.android.tools:desugar_jdk_libs:1.0.10"
...
}
您可以看到我们至少支持 API 19。没有构建错误（使用Gradle 6.1.1），但有以下警告：
Warning in synthesized for lambda desugaring:
Type `j$.$r8$wrapper$java$util$function$Function$-V-WRP` was not found, it is required for default or static interface methods desugaring of `java.util.Comparator java.time.chrono.-$$Lambda$AbstractChronology$j22w8kHhJoqCd56hhLQK1G0VLFw.thenComparing($-vivified-$.java.util.function.Function)`
Warning in synthesized for lambda desugaring:
Type `j$.$r8$wrapper$java$util$function$ToLongFunction$-V-WRP` was not found, it is required for default or static interface methods desugaring of `java.util.Comparator java.time.chrono.-$$Lambda$AbstractChronology$j22w8kHhJoqCd56hhLQK1G0VLFw.thenComparingLong($-vivified-$.java.util.function.ToLongFunction)`
Warning in synthesized for lambda desugaring:
Type `j$.$r8$wrapper$java$util$function$ToDoubleFunction$-V-WRP` was not found, it is required for default or static interface methods desugaring of `java.util.Comparator java.time.chrono.-$$Lambda$AbstractChronology$j22w8kHhJoqCd56hhLQK1G0VLFw.thenComparingDouble($-vivified-$.java.util.function.ToDoubleFunction)`
Warning in synthesized for lambda desugaring:
Type `j$.$r8$wrapper$java$util$function$ToIntFunction$-V-WRP` was not found, it is required for default or static interface methods desugaring of `java.util.Comparator java.time.chrono.-$$Lambda$AbstractChronology$j22w8kHhJoqCd56hhLQK1G0VLFw.thenComparingInt($-vivified-$.java.util.function.ToIntFunction)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ConcurrentHashMap$EntryIterator.class:
Type `j$.$r8$wrapper$java$util$function$Consumer$-V-WRP` was not found, it is required for default or static interface methods desugaring of `void java.util.concurrent.ConcurrentHashMap$EntryIterator.forEachRemaining($-vivified-$.java.util.function.Consumer)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ConcurrentHashMap$CollectionView.class:
Type `j$.$r8$wrapper$java$util$stream$Stream$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.stream.Stream java.util.concurrent.ConcurrentHashMap$CollectionView.parallelStream()`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ConcurrentHashMap$CollectionView.class:
Type `j$.$r8$wrapper$java$util$Spliterator$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.Spliterator java.util.concurrent.ConcurrentHashMap$CollectionView.spliterator()`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ConcurrentHashMap$CollectionView.class:
Type `j$.$r8$wrapper$java$util$function$Predicate$-V-WRP` was not found, it is required for default or static interface methods desugaring of `boolean java.util.concurrent.ConcurrentHashMap$CollectionView.removeIf($-vivified-$.java.util.function.Predicate)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/DesugarCollections$SynchronizedMap.class:
Type `j$.$r8$wrapper$java$util$function$BiFunction$-V-WRP` was not found, it is required for default or static interface methods desugaring of `void java.util.DesugarCollections$SynchronizedMap.replaceAll($-vivified-$.java.util.function.BiFunction)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/DesugarCollections$SynchronizedMap.class:
Type `j$.$r8$wrapper$java$util$function$BiConsumer$-V-WRP` was not found, it is required for default or static interface methods desugaring of `void java.util.DesugarCollections$SynchronizedMap.forEach($-vivified-$.java.util.function.BiConsumer)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ThreadLocalRandom.class:
Type `j$.$r8$wrapper$java$util$stream$IntStream$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.stream.IntStream java.util.concurrent.ThreadLocalRandom.ints()`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ThreadLocalRandom.class:
Type `j$.$r8$wrapper$java$util$stream$LongStream$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.stream.LongStream java.util.concurrent.ThreadLocalRandom.longs()`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ThreadLocalRandom.class:
Type `j$.$r8$wrapper$java$util$stream$DoubleStream$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.stream.DoubleStream java.util.concurrent.ThreadLocalRandom.doubles(long)`
Warning: Type `java.util.OptionalConversions` was not found, it is required for default or static interface methods desugaring of `java.util.OptionalLong j$.$r8$wrapper$java$util$stream$LongStream$-WRP.findAny()`
Warning: Type `java.util.LongSummaryStatisticsConversions` was not found, it is required for default or static interface methods desugaring of `java.util.LongSummaryStatistics j$.$r8$wrapper$java$util$stream$LongStream$-WRP.summaryStatistics()`
Warning: Type `java.util.IntSummaryStatisticsConversions` was not found, it is required for default or static interface methods desugaring of `java.util.IntSummaryStatistics j$.$r8$wrapper$java$util$stream$IntStream$-WRP.summaryStatistics()`
Warning: Type `java.util.DoubleSummaryStatisticsConversions` was not found, it is required for default or static interface methods desugaring of `java.util.DoubleSummaryStatistics j$.$r8$wrapper$java$util$stream$DoubleStream$-WRP.summaryStatistics()`
当我 运行 应用程序启动 activity 并在代码中使用以下可选时，应用程序崩溃
I/ApplicationBase: Testing Java 8
E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
Process: com.example.app.DEV, PID: 8265
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NoClassDefFoundError: j$.util.Optional
at com.example.app.ApplicationBase.launch(ApplicationBase.java:251)
at com.example.app.LaunchTask.doInBackground(LaunchTask.java:19)
at com.example.app.LaunchTask.doInBackground(LaunchTask.java:6)
at android.os.AsyncTask.call(AsyncTask.java:288)
ApplicationBase.java
import androidx.multidex.MultiDexApplication
import java.util.Optional;
public class ApplicationBase extends MultiDexApplication implements LaunchTask.Launcher {
@SuppressLint("NewApi")
@Override
public void launch() throws IOException {
IOHandler ioHandler = new AndroidAppIOHandler(getApplicationContext());
Logger.i(TAG, "Testing Java 8");
Optional.of("xyz").ifPresent(__ -> Logger.i(TAG, "Good"));
Logger.i(TAG, "Tested Java 8");
...
}
...
}
我错过了什么？
阅读 后，似乎发现 launch() 方法存在问题，我们进行了进一步调查。我可以确认 MultiDex.install() 在 launch().
之前被调用
如果我在 AndroidAppIoHandler 中添加一个 Optional，像这样：
public AndroidAppIOHandler(Context context) {
this.context = context;
final Optional<Context> context1 = Optional.of(context);
Log.d("TESTMULTIDEX1", context1.getClass() + " " + context1.get().getClass() + " " + context1.toString());
}
然后我看到：
D/TESTMULTIDEX1( 2826): class j$.util.Optional class com.example.app.ApplicationBase Optional[com.example.app.ApplicationBase@9d006a00]
从launch()的第一行开始调用。
如果我将 Optional 添加到 launch() 方法的下一行，如下所示：
public void launch() throws IOException {
IOHandler ioHandler = new AndroidAppIOHandler(getApplicationContext());
final Optional<IOHandler> ioHandler1 = Optional.of(ioHandler);
...
然后我看到：
java.lang.NoClassDefFoundError: j$.util.Optional
在同一执行中，在打印上面的其他消息后！
如果崩溃仅出现在 API 级别 19 的设备上，原因可能是在使用脱糖类型之前未调用 MultiDex.install。
java.util.Optional 的实现（在脱糖库中称为 j$.util.Optional ）在一个单独的 DEX 文件中。在不支持原生 multi dex（在 API 级别 21 中添加）的设备上，必须先调用 MultiDex.install 才能使用脱糖类型。在 MultiDexApplication 中，对 MultiDex.install 的调用在 attachBaseContext 中。如果在 MultiDex.install 之前调用 launch 方法，您将看到 NoClassDefFoundError.
我遇到了一个非常相似的问题，就我而言，结果是 Android Gradle 插件中的 a bug。长话短说，AGP 在不同的 DEX 文件中生成一些相同的包装器 类，这些包装器在旧的 Android 版本上会造成 Dalvik/ART。而且问题只出现在调试版本上，因为 R8/ProGuard 在发布版本中删除了 类 的重复数据。
那个问题有a workaround：
buildscript {
repositories {
maven {
url "https://storage.googleapis.com/r8-releases/raw/master" // NOTICE 'master' here!
}
}
dependencies {
classpath 'com.android.tools:r8:f03be11f11b8405b69876d05337e917a5519e52a' // Must be before the Gradle Plugin for Android.
classpath 'com.android.tools.build:gradle:X.Y.Z' // Your current AGP version.
}
}
希望这对您有所帮助。
我在仍然支持 Android 4.1 的旧版应用程序中遇到了同样的问题。在创建示例项目并尝试重现错误后，我发现了问题（或错误？）。
不幸的是，Android 4.4 或更低版本的设备似乎无法使用任何 Java 8 class 或将由 Core Library Desugaring 在 onCreate 方法中触及的接口应用程序。
这似乎是一个奇怪的多重索引issue/bug。
我尝试了以下方法：
class CoreApplication : MultiDexApplication() {
override fun attachBaseContext(base: Context?) {
//adding the new GMS causes to many Methods in APK, therefore configure Application as MultiDex
super.attachBaseContext(base)
MultiDex.install(this)
}
override fun onCreate() {
super.onCreate()
Optional.of("TEst")
}
}
这将导致您提到的崩溃：
03-22 18:36:09.231 657-657/com.plauzeware.CoreLibraryDesugeringCrashOnAndroidKitkat E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.plauzeware.CoreLibraryDesugeringCrashOnAndroidKitkat, PID: 657
java.lang.NoClassDefFoundError: j$.util.Optional
at com.plauzeware.corelibrarydesugeringcrashonandroidkitkat.CoreApplication.onCreate(Application.kt:17)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1030)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4409)
at android.app.ActivityThread.access00(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1270)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
但是当我将对 Optional 的调用包装在一个助手中时 class
class Loader {
companion object {
fun load() {
Optional.of("TEst")
}
}
}
并在我的 onCreate 函数中调用它
class CoreApplication : MultiDexApplication() {
override fun attachBaseContext(base: Context?) {
//adding the new GMS causes to many Methods in APK, therefore configure Application as MultiDex
super.attachBaseContext(base)
MultiDex.install(this)
}
override fun onCreate() {
super.onCreate()
Loader.load()
}
}
它会起作用的。我认为这是一个错误，我将提交错误报告并使用 Link 更新此答案。
因为 multidexing 问题也触及像 Iterable 这样的基本界面，所以解决这些错误真的很痛苦。特别是因为我们仍然使用 OrmLite，它会一直使用 Iterable。
我已经添加了我的代码以供参考我的 Github
更新：
Here 是错误报告的 link。
这已通过升级到 Android Gradle 构建插件 4.2.0 解决，其中 R8 正确脱糖。
我正在将 Android 应用程序从使用 Proguard 的脱糖转换为 Android Gradle 构建插件 4.0.0 中提供的新 R8 脱糖。
我已按照 in the official documentation 中详细说明的步骤启用 Java 8 库脱糖：
gradle.properties
projectJavaVersion = 1.8
android.useAndroidX=true
android.enableJetifier=true
应用build.gradle
plugins {
id 'com.android.application'
id 'kotlin-android'
}
android {
buildToolsVersion '29.0.2'
compileSdkVersion 29
compileOptions {
coreLibraryDesugaringEnabled true
sourceCompatibility projectJavaVersion
targetCompatibility projectJavaVersion
}
kotlinOptions {
jvmTarget = projectJavaVersion
}
defaultConfig {
multiDexEnabled true
minSdkVersion 19
targetSdkVersion 23
applicationId = 'com.example.app'
}
buildTypes {
release {
...
minifyEnabled true
}
debug {
debuggable true
minifyEnabled true
}
}
}
dependencies {
coreLibraryDesugaring "com.android.tools:desugar_jdk_libs:1.0.10"
...
}
您可以看到我们至少支持 API 19。没有构建错误（使用Gradle 6.1.1），但有以下警告：
Warning in synthesized for lambda desugaring:
Type `j$.$r8$wrapper$java$util$function$Function$-V-WRP` was not found, it is required for default or static interface methods desugaring of `java.util.Comparator java.time.chrono.-$$Lambda$AbstractChronology$j22w8kHhJoqCd56hhLQK1G0VLFw.thenComparing($-vivified-$.java.util.function.Function)`
Warning in synthesized for lambda desugaring:
Type `j$.$r8$wrapper$java$util$function$ToLongFunction$-V-WRP` was not found, it is required for default or static interface methods desugaring of `java.util.Comparator java.time.chrono.-$$Lambda$AbstractChronology$j22w8kHhJoqCd56hhLQK1G0VLFw.thenComparingLong($-vivified-$.java.util.function.ToLongFunction)`
Warning in synthesized for lambda desugaring:
Type `j$.$r8$wrapper$java$util$function$ToDoubleFunction$-V-WRP` was not found, it is required for default or static interface methods desugaring of `java.util.Comparator java.time.chrono.-$$Lambda$AbstractChronology$j22w8kHhJoqCd56hhLQK1G0VLFw.thenComparingDouble($-vivified-$.java.util.function.ToDoubleFunction)`
Warning in synthesized for lambda desugaring:
Type `j$.$r8$wrapper$java$util$function$ToIntFunction$-V-WRP` was not found, it is required for default or static interface methods desugaring of `java.util.Comparator java.time.chrono.-$$Lambda$AbstractChronology$j22w8kHhJoqCd56hhLQK1G0VLFw.thenComparingInt($-vivified-$.java.util.function.ToIntFunction)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ConcurrentHashMap$EntryIterator.class:
Type `j$.$r8$wrapper$java$util$function$Consumer$-V-WRP` was not found, it is required for default or static interface methods desugaring of `void java.util.concurrent.ConcurrentHashMap$EntryIterator.forEachRemaining($-vivified-$.java.util.function.Consumer)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ConcurrentHashMap$CollectionView.class:
Type `j$.$r8$wrapper$java$util$stream$Stream$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.stream.Stream java.util.concurrent.ConcurrentHashMap$CollectionView.parallelStream()`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ConcurrentHashMap$CollectionView.class:
Type `j$.$r8$wrapper$java$util$Spliterator$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.Spliterator java.util.concurrent.ConcurrentHashMap$CollectionView.spliterator()`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ConcurrentHashMap$CollectionView.class:
Type `j$.$r8$wrapper$java$util$function$Predicate$-V-WRP` was not found, it is required for default or static interface methods desugaring of `boolean java.util.concurrent.ConcurrentHashMap$CollectionView.removeIf($-vivified-$.java.util.function.Predicate)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/DesugarCollections$SynchronizedMap.class:
Type `j$.$r8$wrapper$java$util$function$BiFunction$-V-WRP` was not found, it is required for default or static interface methods desugaring of `void java.util.DesugarCollections$SynchronizedMap.replaceAll($-vivified-$.java.util.function.BiFunction)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/DesugarCollections$SynchronizedMap.class:
Type `j$.$r8$wrapper$java$util$function$BiConsumer$-V-WRP` was not found, it is required for default or static interface methods desugaring of `void java.util.DesugarCollections$SynchronizedMap.forEach($-vivified-$.java.util.function.BiConsumer)`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ThreadLocalRandom.class:
Type `j$.$r8$wrapper$java$util$stream$IntStream$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.stream.IntStream java.util.concurrent.ThreadLocalRandom.ints()`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ThreadLocalRandom.class:
Type `j$.$r8$wrapper$java$util$stream$LongStream$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.stream.LongStream java.util.concurrent.ThreadLocalRandom.longs()`
Warning in /Users/username/.gradle/caches/modules-2/files-2.1/com.android.tools/desugar_jdk_libs/1.0.4/961afbdb3d41eebfb63b8c8ccdc97453b869964e/desugar_jdk_libs-1.0.4.jar:java/util/concurrent/ThreadLocalRandom.class:
Type `j$.$r8$wrapper$java$util$stream$DoubleStream$-WRP` was not found, it is required for default or static interface methods desugaring of `$-vivified-$.java.util.stream.DoubleStream java.util.concurrent.ThreadLocalRandom.doubles(long)`
Warning: Type `java.util.OptionalConversions` was not found, it is required for default or static interface methods desugaring of `java.util.OptionalLong j$.$r8$wrapper$java$util$stream$LongStream$-WRP.findAny()`
Warning: Type `java.util.LongSummaryStatisticsConversions` was not found, it is required for default or static interface methods desugaring of `java.util.LongSummaryStatistics j$.$r8$wrapper$java$util$stream$LongStream$-WRP.summaryStatistics()`
Warning: Type `java.util.IntSummaryStatisticsConversions` was not found, it is required for default or static interface methods desugaring of `java.util.IntSummaryStatistics j$.$r8$wrapper$java$util$stream$IntStream$-WRP.summaryStatistics()`
Warning: Type `java.util.DoubleSummaryStatisticsConversions` was not found, it is required for default or static interface methods desugaring of `java.util.DoubleSummaryStatistics j$.$r8$wrapper$java$util$stream$DoubleStream$-WRP.summaryStatistics()`
当我 运行 应用程序启动 activity 并在代码中使用以下可选时，应用程序崩溃
I/ApplicationBase: Testing Java 8
E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
Process: com.example.app.DEV, PID: 8265
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NoClassDefFoundError: j$.util.Optional
at com.example.app.ApplicationBase.launch(ApplicationBase.java:251)
at com.example.app.LaunchTask.doInBackground(LaunchTask.java:19)
at com.example.app.LaunchTask.doInBackground(LaunchTask.java:6)
at android.os.AsyncTask.call(AsyncTask.java:288)
ApplicationBase.java
import androidx.multidex.MultiDexApplication
import java.util.Optional;
public class ApplicationBase extends MultiDexApplication implements LaunchTask.Launcher {
@SuppressLint("NewApi")
@Override
public void launch() throws IOException {
IOHandler ioHandler = new AndroidAppIOHandler(getApplicationContext());
Logger.i(TAG, "Testing Java 8");
Optional.of("xyz").ifPresent(__ -> Logger.i(TAG, "Good"));
Logger.i(TAG, "Tested Java 8");
...
}
...
}
我错过了什么？
阅读 launch() 方法存在问题，我们进行了进一步调查。我可以确认 MultiDex.install() 在 launch().
如果我在 AndroidAppIoHandler 中添加一个 Optional，像这样：
public AndroidAppIOHandler(Context context) {
this.context = context;
final Optional<Context> context1 = Optional.of(context);
Log.d("TESTMULTIDEX1", context1.getClass() + " " + context1.get().getClass() + " " + context1.toString());
}
然后我看到：
D/TESTMULTIDEX1( 2826): class j$.util.Optional class com.example.app.ApplicationBase Optional[com.example.app.ApplicationBase@9d006a00]
从launch()的第一行开始调用。
如果我将 Optional 添加到 launch() 方法的下一行，如下所示：
public void launch() throws IOException {
IOHandler ioHandler = new AndroidAppIOHandler(getApplicationContext());
final Optional<IOHandler> ioHandler1 = Optional.of(ioHandler);
...
然后我看到：
java.lang.NoClassDefFoundError: j$.util.Optional
在同一执行中，在打印上面的其他消息后！
如果崩溃仅出现在 API 级别 19 的设备上，原因可能是在使用脱糖类型之前未调用 MultiDex.install。
java.util.Optional 的实现（在脱糖库中称为 j$.util.Optional ）在一个单独的 DEX 文件中。在不支持原生 multi dex（在 API 级别 21 中添加）的设备上，必须先调用 MultiDex.install 才能使用脱糖类型。在 MultiDexApplication 中，对 MultiDex.install 的调用在 attachBaseContext 中。如果在 MultiDex.install 之前调用 launch 方法，您将看到 NoClassDefFoundError.
我遇到了一个非常相似的问题，就我而言，结果是 Android Gradle 插件中的 a bug。长话短说，AGP 在不同的 DEX 文件中生成一些相同的包装器 类，这些包装器在旧的 Android 版本上会造成 Dalvik/ART。而且问题只出现在调试版本上，因为 R8/ProGuard 在发布版本中删除了 类 的重复数据。
那个问题有a workaround：
buildscript {
repositories {
maven {
url "https://storage.googleapis.com/r8-releases/raw/master" // NOTICE 'master' here!
}
}
dependencies {
classpath 'com.android.tools:r8:f03be11f11b8405b69876d05337e917a5519e52a' // Must be before the Gradle Plugin for Android.
classpath 'com.android.tools.build:gradle:X.Y.Z' // Your current AGP version.
}
}
希望这对您有所帮助。
我在仍然支持 Android 4.1 的旧版应用程序中遇到了同样的问题。在创建示例项目并尝试重现错误后，我发现了问题（或错误？）。
不幸的是，Android 4.4 或更低版本的设备似乎无法使用任何 Java 8 class 或将由 Core Library Desugaring 在 onCreate 方法中触及的接口应用程序。
这似乎是一个奇怪的多重索引issue/bug。
我尝试了以下方法：
class CoreApplication : MultiDexApplication() {
override fun attachBaseContext(base: Context?) {
//adding the new GMS causes to many Methods in APK, therefore configure Application as MultiDex
super.attachBaseContext(base)
MultiDex.install(this)
}
override fun onCreate() {
super.onCreate()
Optional.of("TEst")
}
}
这将导致您提到的崩溃：
03-22 18:36:09.231 657-657/com.plauzeware.CoreLibraryDesugeringCrashOnAndroidKitkat E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.plauzeware.CoreLibraryDesugeringCrashOnAndroidKitkat, PID: 657
java.lang.NoClassDefFoundError: j$.util.Optional
at com.plauzeware.corelibrarydesugeringcrashonandroidkitkat.CoreApplication.onCreate(Application.kt:17)
at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1030)
at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4409)
at android.app.ActivityThread.access00(ActivityThread.java:139)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1270)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:136)
at android.app.ActivityThread.main(ActivityThread.java:5086)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
at dalvik.system.NativeStart.main(Native Method)
但是当我将对 Optional 的调用包装在一个助手中时 class
class Loader {
companion object {
fun load() {
Optional.of("TEst")
}
}
}
并在我的 onCreate 函数中调用它
class CoreApplication : MultiDexApplication() {
override fun attachBaseContext(base: Context?) {
//adding the new GMS causes to many Methods in APK, therefore configure Application as MultiDex
super.attachBaseContext(base)
MultiDex.install(this)
}
override fun onCreate() {
super.onCreate()
Loader.load()
}
}
它会起作用的。我认为这是一个错误，我将提交错误报告并使用 Link 更新此答案。
因为 multidexing 问题也触及像 Iterable 这样的基本界面，所以解决这些错误真的很痛苦。特别是因为我们仍然使用 OrmLite，它会一直使用 Iterable。
我已经添加了我的代码以供参考我的 Github
更新：
Here 是错误报告的 link。
这已通过升级到 Android Gradle 构建插件 4.2.0 解决，其中 R8 正确脱糖。