Can not debug java.lang.NoClassDefFoundError: com/

问题:

I am trying to make an applet for uploading files to openstack swift using jclouds. And I am facing the NoClassDefFoundError, following is the stacktrace:

Exception in thread "main" java.lang.NoClassDefFoundError: com/google/inject/internal/util/$Preconditions
    at org.nnsoft.guice.rocoto.configuration.ConfigurationModule.configure(ConfigurationModule.java:64)
    at com.google.inject.AbstractModule.configure(AbstractModule.java:59)
    at com.google.inject.spi.Elements$RecordingBinder.install(Elements.java:223)
    at com.google.inject.spi.Elements.getElements(Elements.java:101)
    at com.google.inject.spi.Elements.getElements(Elements.java:92)
    at org.nnsoft.guice.rocoto.Rocoto.expandVariables(Rocoto.java:52)
    at org.nnsoft.guice.rocoto.Rocoto.expandVariables(Rocoto.java:47)
    at org.jclouds.config.BindPropertiesToExpandedValues.configure(BindPropertiesToExpandedValues.java:47)
    at com.google.inject.AbstractModule.configure(AbstractModule.java:59)
    at com.google.inject.spi.Elements$RecordingBinder.install(Elements.java:223)
    at com.google.inject.spi.Elements.getElements(Elements.java:101)
    at com.google.inject.internal.InjectorShell$Builder.build(InjectorShell.java:133)
    at com.google.inject.internal.InternalInjectorCreator.build(InternalInjectorCreator.java:103)
    at com.google.inject.Guice.createInjector(Guice.java:95)
    at com.google.inject.Guice.createInjector(Guice.java:72)
    at com.google.inject.Guice.createInjector(Guice.java:62)
    at org.jclouds.ContextBuilder.expandProperties(ContextBuilder.java:385)
    at org.jclouds.ContextBuilder.buildInjector(ContextBuilder.java:320)
    at org.jclouds.ContextBuilder.buildView(ContextBuilder.java:620)
    at org.jclouds.ContextBuilder.buildView(ContextBuilder.java:600)
    at com.cdac.appletclass.Test.main(Test.java:56)
Caused by: java.lang.ClassNotFoundException: com.google.inject.internal.util.$Preconditions
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
    ... 21 more

I googled for com/google/inject/internal/util/$Preconditions, and came to know that it is part of guice-3.0.jar. But guice-3.0.jar is already there in my project. How to debug then? any help..???

回答1:

I suggest printing out what's on your classpath from within your app (see this answer). That way you'll know exactly what classpath your app is using, if there's anything missing or any collisions.

回答2:

Problem is solved now. It was a mistake between guice 3.0 and guice-3.0.0, because both are having the same maven artifact-id but group-id was different.

回答3:

Open the property of your project and add a dependency library.