Exception java.lang.IncompatibleClassChangeError while running Groovy in Eclipse Juno

Question

I have recently downloaded Eclipse Juno and installed latest Groovy plugin.

Now here is how my Groovy file looks like.

package groovy_support

class TimePass {
static void main(def args){
    println "Hello World"
}
}

When i run this from either my previous eclipse version (indigo) or from command line, it runs. On Eclipse Juno, however, it complains with following exception on Eclipse console.

Caught: java.lang.IncompatibleClassChangeError: Found class org.objectweb.asm.ClassVisitor, but interface was expected
java.lang.IncompatibleClassChangeError: Found class org.objectweb.asm.ClassVisitor, but interface was expected

Note that "Groovy Libraries" are already on classpath.

Now what am i doing wrong here?

Answer 1

Are you on the latest groovy/dependent jars? .

The java.lang.IncompatibleClassChangeError happens due to back ward compatibility issues. The client code needs to be recompiled to resolve it.

The specific error you are seeing is because org.objectweb.asm.ClassVisitor is an Interface in asm 3.2 and a Class in asm 4.0 onwards.

Answer 2

I had the same problem using Spring and Groovy in one module. Spring in 3.1.2 still uses older ASM, Groovy uses the one with the class. While it may be possible to adjust some excludes, I bet it's not always an option.

After reading this thread I decided to do with groovy-all.jar instead of the list of all the Groovy needed libs. If that is an option for you, it might be easy way how to avoid any further problems.