maven的坑: Exception in thread "pool-1-thread-1" java.lang.NoClassDefFoundError: org/eclipse/aether/spi/connector/Transfer$State

Exception in thread "main" java.lang.NoClassDefFoundError: org/eclipse/aether/spi/connector/Transfer$State
    at org.eclipse.aether.connector.wagon.WagonRepositoryConnector$GetTask.run(WagonRepositoryConnector.java:608)
    at org.eclipse.aether.util.concurrency.RunnableErrorForwarder$1.run(RunnableErrorForwarder.java:67)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassNotFoundException: org.eclipse.aether.spi.connector.Transfer$State
    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)
    ... 5 more