ClassNotFoundException with Guice 2.0

Question

The code below generates an error using Guice 2.0. With Guice 1.0 everything is fine. The JDK is Java 6 update 15.

public class App {
    public static void main(String[] args) {
     Guice.createInjector(new AbstractModule() {
      @Override
      protected void configure() {
       // just testing 
      }
     });
    }
}

The error is:

Exception in thread "main" java.lang.NoClassDefFoundError: [Lorg/aopalliance/intercept/MethodInterceptor;
    at java.lang.Class.getDeclaredMethods0(Native Method)
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2427)
    at java.lang.Class.getDeclaredMethods(Class.java:1791)
    at com.google.inject.internal.ProviderMethodsModule.getProviderMethods(ProviderMethodsModule.java:78)
    at com.google.inject.internal.ProviderMethodsModule.configure(ProviderMethodsModule.java:70)
    at com.google.inject.spi.Elements$RecordingBinder.install(Elements.java:223)
    at com.google.inject.spi.Elements$RecordingBinder.install(Elements.java:232)
    at com.google.inject.spi.Elements.getElements(Elements.java:101)
    at com.google.inject.InjectorShell$Builder.build(InjectorShell.java:135)
    at com.google.inject.InjectorBuilder.build(InjectorBuilder.java:102)
    at com.google.inject.Guice.createInjector(Guice.java:92)
    at com.google.inject.Guice.createInjector(Guice.java:69)
    at com.google.inject.Guice.createInjector(Guice.java:59)
    at App.main(App.java:6)
Caused by: java.lang.ClassNotFoundException: org.aopalliance.intercept.MethodInterceptor
    at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
    ... 14 more

What can be the problem?

Answer 1

You have missed to include a dependency jar with the class org.aopalliance.intercept.MethodInterceptor in the classpath.

Answer 2

as Boris Pavlović mentions in his answer, you're missing a jar. Specifically the aopalliance.jar file, which comes in the guice zip file

Alternatively, you might try using guice-2.0-no_aop.jar, but I'm not sure if that will work.

Adding this file to the classpath depends on which tool you use to run your java code.

• If you are running java from the command line:

windows: java -cp aopalliance.jar;guice-2.0.jar;other_jars.jar YourMainClass
*nix:    java -cp aopalliance.jar:guice-2.0.jar:other_jars.jar YourMainClass

• If you are running java from Eclipse, typically you'll have some type of lib/ directory. Put your jar there, then right-click on the jar -> Build Path -> Add to Build Path