NoClassDefFoundError when project imported to Eclipse?

Question

I am working on an app which uses Commonslang.jar libraries. I was trying to setup it on a new system with newly installed Eclipse.The project is not showing any error But when I run the project it force closes with NoClassDefFoundError at each point where I use Commonslang lib.

I dont know how to fix this problem.Please help?

Answer 1

I think there are "lib" folder in your project directory so just change it "libs" instead of "lib" and clean project and check it..

> Note: No need to build path for any third party library

Answer 2

You need to create libs folder in your project and copy that jar file there. Then in eclipse, right-click on that jar file (which is in libs folder) select Build Path and then select Add to Build Path.

Remember: if you are using a jar file in your Android Library Project, and associating that library project with your regular UI project, it won't be enough. You must need to include that jar file (as described above) in both of your projects (Android Library and UI project) to make it work.

Answer 3

Have you added the jar to the Java Build Path? Go to the Properties for the Project and select Java Build Path -> Libraries tab then add the external jar there.