“Conversion to Dalvik format failed with error 1” on external JAR

Question

In my Android application in Eclipse I get the following error.

UNEXPECTED TOP-LEVEL EXCEPTION:
java.lang.IllegalArgumentException: already add

Answer 1

I ran into this problem because the Android-Maven-plugin in Eclipse was apparently not recognizing transitive references and references referenced twice from a couple of projects (including an Android library project), and including them more than once. I had to use hocus-pocus to get everything included only once, even though Maven is supposed to take care of all this.

For example, I had a core library globalmentor-core, that was also used by globalmentor-google and globalmentor-android (the latter of which is an Android library). In the globalmentor-android pom.xml I had to mark the dependency as "provided" as well as excluded from other libraries in which it was transitively included:

    
        com.globalmentor
        globalmentor-core
        1.0-SNAPSHOT
        
        provided
    

Then in the final application pom.xml I had to use the right trickery to allow only one inclusion path---as well as not explicitly including the core library:

    
    
    
    
    
    

    
        com.globalmentor
        globalmentor-google
        1.0-SNAPSHOT
        
            
            
                com.globalmentor
                globalmentor-core
            
        
    

    
        com.globalmentor
        globalmentor-android
        1.0-SNAPSHOT