mvn Caused by: java.lang.NoClassDefFoundError: org/sonatype/aether/version/Versi

mvn dependency:tree 报了这么个错：

写道

import: Entry[import from realm ClassRealm[maven.api, parent: null]]

-----------------------------------------------------

at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:168)
at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
... 20 more
Caused by: org.apache.maven.plugin.PluginContainerException: A required class was missing while executing org.apache.maven.plugins:maven-dependency-plugin:2.6:tree: org/sonatype/aether/version/VersionConstraint

at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:166)
... 21 more
Caused by: java.lang.NoClassDefFoundError: org/sonatype/aether/version/VersionConstraint
at java.lang.Class.getDeclaredMethods0(Native Method)
at java.lang.Class.privateGetDeclaredMethods(Class.java:2442)
at java.lang.Class.getDeclaredMethods(Class.java:1808)
at com.google.inject.spi.InjectionPoint.getInjectionPoints(InjectionPoint.java:688)
at com.google.inject.spi.InjectionPoint.forInstanceMethodsAndFields(InjectionPoint.java:380)
at com.google.inject.internal.ConstructorBindingImpl.getInternalDependencies(ConstructorBindingImpl.java:164)
at com.google.inject.internal.InjectorImpl.getInternalDependencies(InjectorImpl.java:613)
at com.google.inject.internal.InjectorImpl.cleanup(InjectorImpl.java:569)
at com.google.inject.internal.InjectorImpl.initializeJitBinding(InjectorImpl.java:555)
at com.google.inject.internal.InjectorImpl.createJustInTimeBinding(InjectorImpl.java:884)
at com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive(InjectorImpl.java:805)
at com.google.inject.internal.InjectorImpl.getJustInTimeBinding(InjectorImpl.java:282)
at com.google.inject.internal.InjectorImpl.getBindingOrThrow(InjectorImpl.java:214)
at com.google.inject.internal.InjectorImpl.getProviderOrThrow(InjectorImpl.java:1006)
at com.google.inject.internal.InjectorImpl.getProvider(InjectorImpl.java:1038)
at com.google.inject.internal.InjectorImpl.getProvider(InjectorImpl.java:1001)
at com.google.inject.internal.InjectorImpl.getInstance(InjectorImpl.java:1051)
at org.eclipse.sisu.space.AbstractDeferredClass.get(AbstractDeferredClass.java:48)
at com.google.inject.internal.ProviderInternalFactory.provision(ProviderInternalFactory.java:81)
at com.google.inject.internal.InternalFactoryToInitializableAdapter.provision(InternalFactoryToInitializableAdapter.java:53)
at com.google.inject.internal.ProviderInternalFactory$1.call(ProviderInternalFactory.java:65)
at com.google.inject.internal.ProvisionListenerStackCallback$Provision.provision(ProvisionListenerStackCallback.java:115)
at org.eclipse.sisu.bean.BeanScheduler$Activator.onProvision(BeanScheduler.java:176)
at com.google.inject.internal.ProvisionListenerStackCallback$Provision.provision(ProvisionListenerStackCallback.java:126)
at com.google.inject.internal.ProvisionListenerStackCallback.provision(ProvisionListenerStackCallback.java:68)
at com.google.inject.internal.ProviderInternalFactory.circularGet(ProviderInternalFactory.java:63)
at com.google.inject.internal.InternalFactoryToInitializableAdapter.get(InternalFactoryToInitializableAdapter.java:45)
at com.google.inject.internal.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:46)
at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1103)
at com.google.inject.internal.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:40)
at com.google.inject.internal.SingletonScope$1.get(SingletonScope.java:145)
at com.google.inject.internal.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:41)
at com.google.inject.internal.InjectorImpl$2$1.call(InjectorImpl.java:1016)
at com.google.inject.internal.InjectorImpl.callInContext(InjectorImpl.java:1092)
at com.google.inject.internal.InjectorImpl$2.get(InjectorImpl.java:1012)
at org.eclipse.sisu.inject.LazyBeanEntry.getValue(LazyBeanEntry.java:81)
at org.eclipse.sisu.plexus.LazyPlexusBean.getValue(LazyPlexusBean.java:51)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:263)
at org.codehaus.plexus.DefaultPlexusContainer.lookup(DefaultPlexusContainer.java:243)
at org.apache.maven.shared.dependency.graph.internal.DefaultDependencyGraphBuilder.buildDependencyGraph(DefaultDependencyGraphBuilder.java:60)
at org.apache.maven.plugin.dependency.TreeMojo.execute(TreeMojo.java:202)
at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
... 21 more
Caused by: java.lang.ClassNotFoundException: org.sonatype.aether.version.VersionConstraint
at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
... 63 more

查询：

Caused by: java.lang.NoClassDefFoundError: org/sonatype/aether/version/VersionConstraint 

根据：https://cwiki.apache.org/confluence/display/MAVEN/AetherClassNotFound

https://issues.apache.org/jira/browse/MDEP-407的说明：maven-dependency-plugin2.8以后的版本已经修复了这个问题，所以

使用：

mvn  org.apache.maven.plugins:maven-dependency-plugin:2.8:tree -X

就确实没有这个问题了。