NoClassDefFoundError - Eclipse and Android

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.

I didn't have to put the jar-library in assets or lib(s), but only tick the box for this jar in Properties -> Java Build Path -> "Order and Export" (it was listed before, but not selected)

By adding the external jar into your build path just adds the jar to your package, but it will not be available during runtime.

In order for the jar to be available at runtime, you need to:

• Put the jar under your assets folder
• Include this copy of the jar in your build path
• Go to the export tab on the same popup window
• Check the box against the newly added jar