Gradle 0.9.+/0.9.2 error: Unable to load class

This morning, all Android Studio projects started failing Gradle sync/build/clean with:

> Could not create plugin of type 'AppPlugin'.

The stacktrace looks like:

* Exception is:
org.gradle.api.GradleScriptException: A problem occurred evaluating project ':Project'.
    at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory.java:54)
    at org.gradle.configuration.DefaultScriptPluginFactory$ScriptPluginImpl.apply(DefaultScriptPluginFactory.java:177)
    at org.gradle.configuration.project.BuildScriptProcessor.execute(BuildScriptProcessor.java:38)
    at org.gradle.configuration.project.BuildScriptProcessor.execute(BuildScriptProcessor.java:25)
    at org.gradle.configuration.project.ConfigureActionsProjectEvaluator.evaluate(ConfigureActionsProjectEvaluator.java:34)
    at org.gradle.configuration.project.LifecycleProjectEvaluator.evaluate(LifecycleProjectEvaluator.java:55)
    at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:507)
    at org.gradle.api.internal.project.AbstractProject.evaluate(AbstractProject.java:82)
    at org.gradle.configuration.DefaultBuildConfigurer.configure(DefaultBuildConfigurer.java:31)
    at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:142)
    at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradleLauncher.java:113)
    at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLauncher.java:81)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildController.run(InProcessBuildActionExecuter.java:64)
    at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:33)
    at org.gradle.launcher.cli.ExecuteBuildAction.run(ExecuteBuildAction.java:24)
    at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProcessBuildActionExecuter.java:35)
    at org.gradle.launcher.daemon.server.exec.ExecuteBuild.doBuild(ExecuteBuild.java:45)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.WatchForDisconnection.execute(WatchForDisconnection.java:42)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.ResetDeprecationLogger.execute(ResetDeprecationLogger.java:24)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.StartStopIfBuildAndStop.execute(StartStopIfBuildAndStop.java:33)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.ReturnResult.execute(ReturnResult.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:71)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput$2.call(ForwardClientInput.java:69)
    at org.gradle.util.Swapper.swap(Swapper.java:38)
    at org.gradle.launcher.daemon.server.exec.ForwardClientInput.execute(ForwardClientInput.java:69)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.LogToClient.doBuild(LogToClient.java:60)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:60)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:45)
    at org.gradle.launcher.daemon.server.DaemonStateCoordinator.runCommand(DaemonStateCoordinator.java:186)
    at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy.doBuild(StartBuildOrRespondWithBusy.java:49)
    at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:34)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.HandleStop.execute(HandleStop.java:36)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.DaemonHygieneAction.execute(DaemonHygieneAction.java:39)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.CatchAndForwardDaemonFailure.execute(CatchAndForwardDaemonFailure.java:32)
    at org.gradle.launcher.daemon.server.exec.DaemonCommandExecution.proceed(DaemonCommandExecution.java:125)
    at org.gradle.launcher.daemon.server.exec.DefaultDaemonCommandExecuter.executeCommand(DefaultDaemonCommandExecuter.java:51)
    at org.gradle.launcher.daemon.server.DefaultIncomingConnectionHandler$ConnectionWorker.handleCommand(DefaultIncomingConnectionHandler.java:155)
    at org.gradle.launcher.daemon.server.DefaultIncomingConnectionHandler$ConnectionWorker.receiveAndHandleCommand(DefaultIncomingConnectionHandler.java:128)
    at org.gradle.launcher.daemon.server.DefaultIncomingConnectionHandler$ConnectionWorker.run(DefaultIncomingConnectionHandler.java:116)
    at org.gradle.internal.concurrent.DefaultExecutorFactory$StoppableExecutorImpl$1.run(DefaultExecutorFactory.java:64)
Caused by: org.gradle.api.plugins.PluginInstantiationException: Could not create plugin of type 'AppPlugin'.
    at org.gradle.api.internal.plugins.DefaultPluginRegistry.loadPlugin(DefaultPluginRegistry.java:69)
    at org.gradle.api.internal.plugins.DefaultPluginContainer.providePlugin(DefaultPluginContainer.java:103)
    at org.gradle.api.internal.plugins.DefaultPluginContainer.addPluginInternal(DefaultPluginContainer.java:68)
    at org.gradle.api.internal.plugins.DefaultPluginContainer.apply(DefaultPluginContainer.java:34)
    at org.gradle.api.internal.plugins.DefaultObjectConfigurationAction.applyPlugin(DefaultObjectConfigurationAction.java:101)
    at org.gradle.api.internal.plugins.DefaultObjectConfigurationAction.access$200(DefaultObjectConfigurationAction.java:32)
    at org.gradle.api.internal.plugins.DefaultObjectConfigurationAction$3.run(DefaultObjectConfigurationAction.java:72)
    at org.gradle.api.internal.plugins.DefaultObjectConfigurationAction.execute(DefaultObjectConfigurationAction.java:114)
    at org.gradle.api.internal.project.AbstractPluginAware.apply(AbstractPluginAware.java:39)
    at org.gradle.api.Project$apply.call(Unknown Source)
    at org.gradle.api.internal.project.ProjectScript.apply(ProjectScript.groovy:34)
    at org.gradle.api.Script$apply.callCurrent(Unknown Source)
    at build_5mm5fv0emagtc49feqskf025g1.run(/projectdir/build.gradle:9)
    at org.gradle.groovy.scripts.internal.DefaultScriptRunnerFactory$ScriptRunnerImpl.run(DefaultScriptRunnerFactory.java:52)
    ... 53 more
Caused by: java.lang.NoClassDefFoundError: com/android/builder/testing/api/DeviceProvider
    at com.android.build.gradle.AppPlugin.$getStaticMetaClass(AppPlugin.groovy)
    at com.android.build.gradle.BasePlugin.<init>(BasePlugin.groovy:1908)
    at com.android.build.gradle.AppPlugin.<init>(AppPlugin.groovy:37)
    at org.gradle.api.internal.DependencyInjectingInstantiator.newInstance(DependencyInjectingInstantiator.java:62)
    at org.gradle.api.internal.plugins.DefaultPluginRegistry.loadPlugin(DefaultPluginRegistry.java:67)
    ... 66 more
Caused by: java.lang.ClassNotFoundException: com.android.builder.testing.api.DeviceProvider
    ... 71 more

There's a bug report with a fair bit of activity, but no resolution yet.

This is Android Studio 0.5.2, gradle version 1.11/0.9.2.

Ideas?

回答1:

Per the latest in the bug report, the issue was that version 0.9.2 was being served from Maven central even though all the necessary components weren't yet available (and gradle doesn't register that as a problem). This breaks things because pieces are missing. Version 0.9.2 is now completely available and works, but if you're seeing this bug your gradle cache is corrupted.

To fix:

gradle --refresh-dependencies

or delete

~/.gradle/caches

and then re-sync.

Prior fix, see above for update.

Based on comments in the bug report, it appears that version 0.9.2 is the source of this problem.

To fix, peg the gradle version to known-good version 0.9.1 instead of 0.9.+, 0.+, +, etc.

In your build.gradle file, change

classpath 'com.android.tools.build:gradle:0.9.+'

classpath 'com.android.tools.build:gradle:0.9.1'

回答2:

In order to use the latest Gradle version 0.9.+, you have to update gradlewrapper.properties file too.

Open gradlewrapper.properties file which locate under youProjectPath/gradle/wrapper/gradlewrapper.properties path:

change distributionUrl url From

distributionUrl=http\://services.gradle.org/distributions/gradle-1.10-all.zip

distributionUrl=http\://services.gradle.org/distributions/gradle-1.11-all.zip

After that, I changed build.gradle dependencies to

classpath 'com.android.tools.build:gradle:0.9.+'

and synced gradle files and everything when good.

Cheers