NoClassDefFoundError - Eclipse and Android

Tom R picture Tom R · Feb 11, 2010 · Viewed 115k times · Source

I'm having a problem trying to run an Android app which, up until adding a second external library to its build path, was working fine. Since having added the scoreninja jar, I now get a NoClassDefFoundError when I try to run the app.

Here's the message:

02-11 21:45:26.154: ERROR/AndroidRuntime(3654): java.lang.NoClassDefFoundError: com.scoreninja.adapter.ScoreNinjaAdapter

As all of the build scripts are generated by the Android tools (?), I'm not sure what else I can do other than cleaning and rebuilding or restarting eclipse (I have already tried all three). Does anyone know how I can amend this?

Answer

John O'Connor picture John O'Connor · Mar 29, 2012

I had this problem after updating ADT.

I was storing all of my JAR files in a folder called "lib" and adding the jars to the build path the normal Eclipse way. This worked fine until my update.

After my update, I was getting the NoClassDefFoundError for a class that I could clearly see was included in the jar (checking out the ReferencedLibraries classes).

The solution was to remove my jars from the build path and rename my "lib" folder to "libs". This is an ant convention, and seems to be the way the new ADT finds and includes libraries in an .apk file. Once I did this, everything worked fine.