我今天尝试将构建环境升级到Gradle 4.4，并尝试构建APK时遇到以下错误:
[CIRCULAR REFERENCE:java.lang.NullPointerException]
Caused by: java.lang.NullPointerException
at com.android.tools.r8.dex.DexFileReader$AttributesAndAnnotations.<init>(DexFileReader.java:1129)
at com.android.tools.r8.dex.DexFileReader.addClassDefsTo(DexFileReader.java:682)
at com.android.tools.r8.dex.ApplicationReader$ClassReader.lambda$readDexSources$0(ApplicationReader.java:213)
at java.util.concurrent.ForkJoinTask$AdaptedRunnableAction.exec(ForkJoinTask.java:1386)
然后，我尝试使用Gradle 4.5进行构建，并且看到了相同的错误。该应用程序可以使用Gradle 4.1很好地构建，但是a problem I reported separately迫使我在无法承受神秘的Dex错误的情况下进行升级。
注意:我禁用了Proguard，但是没有效果。
为了执行Gradle升级，我所做的就是更改gradle-wrapper.properties文件中的版本；没有其他代码或配置更改。
这是来自Gradle控制台的完整，很长的堆栈跟踪，以及几条控制台行-表示当抛出此NullPointerException时，Gradle试图完成transformDexArchiveWithDexMerger任务。
Removed unused resources: Binary resource data reduced from 6200KB to 6191KB: Removed 0%
:app:transformClassesWithDexBuilderForPlayStoreDebugprod
D8 is used to build dex.
:app:transformDexArchiveWithDexMergerForPlayStoreDebugprod
D8 is used to merge dex.
java.lang.NullPointerException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.util.concurrent.ForkJoinTask.getThrowableException(ForkJoinTask.java:598)
at java.util.concurrent.ForkJoinTask.reportException(ForkJoinTask.java:677)
at java.util.concurrent.ForkJoinTask.join(ForkJoinTask.java:720)
at com.google.common.collect.ImmutableList.forEach(ImmutableList.java:397)
at com.android.build.gradle.internal.transforms.DexMergerTransform.transform(DexMergerTransform.java:225)
at com.android.build.gradle.internal.pipeline.TransformTask$2.call(TransformTask.java:221)
at com.android.build.gradle.internal.pipeline.TransformTask$2.call(TransformTask.java:217)
at com.android.builder.profile.ThreadRecorder.record(ThreadRecorder.java:102)
at com.android.build.gradle.internal.pipeline.TransformTask.transform(TransformTask.java:212)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.doExecute(IncrementalTaskAction.java:50)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:39)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:26)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:124)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:113)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:95)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:73)
at org.gradle.api.internal.tasks.execution.OutputDirectoryCreatingTaskExecuter.execute(OutputDirectoryCreatingTaskExecuter.java:51)
at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:59)
at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)
at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)
at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter.java:44)
at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:88)
at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:62)
at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:52)
at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:248)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:241)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:230)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:123)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:79)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98)
at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:623)
at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:578)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at java.util.concurrent.ForkJoinTask.getThrowableException(ForkJoinTask.java:598)
at java.util.concurrent.ForkJoinTask.get(ForkJoinTask.java:1005)
at com.android.tools.r8.utils.ThreadUtils.awaitFutures(ThreadUtils.java:21)
at com.android.tools.r8.dex.ApplicationReader.read(ApplicationReader.java:115)
at com.android.tools.r8.dex.ApplicationReader.read(ApplicationReader.java:86)
at com.android.tools.r8.D8.run(D8.java:156)
at com.android.tools.r8.D8.lambda$run$0(D8.java:71)
at com.android.tools.r8.utils.ExceptionUtils.withCompilationHandler(ExceptionUtils.java:58)
at com.android.tools.r8.utils.ExceptionUtils.withD8CompilationHandler(ExceptionUtils.java:45)
at com.android.tools.r8.D8.run(D8.java:67)
at com.android.builder.dexing.D8DexArchiveMerger.mergeDexArchives(D8DexArchiveMerger.java:106)
at com.android.build.gradle.internal.transforms.DexMergerTransformCallable.call(DexMergerTransformCallable.java:101)
at com.android.build.gradle.internal.transforms.DexMergerTransformCallable.call(DexMergerTransformCallable.java:36)
at java.util.concurrent.ForkJoinTask$AdaptedCallable.exec(ForkJoinTask.java:1424)
at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Suppressed: java.util.concurrent.ExecutionException: java.lang.NullPointerException
at java.util.concurrent.ForkJoinTask.get(ForkJoinTask.java:1006)
... 16 more
[CIRCULAR REFERENCE:java.lang.NullPointerException]
Caused by: java.lang.NullPointerException
at com.android.tools.r8.dex.DexFileReader$AttributesAndAnnotations.<init>(DexFileReader.java:1129)
at com.android.tools.r8.dex.DexFileReader.addClassDefsTo(DexFileReader.java:682)
at com.android.tools.r8.dex.ApplicationReader$ClassReader.lambda$readDexSources$0(ApplicationReader.java:213)
at java.util.concurrent.ForkJoinTask$AdaptedRunnableAction.exec(ForkJoinTask.java:1386)
最佳答案
原来，这是由于我们使用了Butterknife插件的9.0.0-SNAPSHOT版本。
当我们从此切换时:classpath 'com.jakewharton:butterknife-gradle-plugin:9.0.0-SNAPSHOT'
...到为我们构建的旧版本:classpath 'com.jakewharton:butterknife-gradle-plugin:8.5.1'
...循环引用NullPointerException Dex错误消失了。
故事的寓意:坚持使用Gradle插件的稳定，特定版本。
关于android - 循环引用:DexFileReader中的java.lang.NullPointerException，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/48971092/