java.lang.NoClassDefFoundError: how do I fix this error?

Question

I am developing an Android application which makes use of the Osmdroid maps api. I have added the library as an external jar in my build path and I do not get any errors during compile time. However, upon device deployment I get the following error:

03-27 16:18:50.986: E/AndroidRuntime(3306): java.lang.NoClassDefFoundError: org.osmdroid.util.GeoPoint

I have done some googgling and it is still a mystery to me.

Here is my IDE configuration.

Eclipse: Indigo Release version 2  
Java SDK: 1.6.0_31  
Android SDK: 17

Answer 1

您需要进入Build Path / Order and Export，并从SDK 17开始检查库。然后清理您的项目。

Answer 2

I doubt about you and your project. From my viewpoint, I see you have a good design. But why are you working with Build Path / Order and Export? Honestly I've never gone to that tab from the first day I worked with Eclipse.

To import jar files as libraries, use tab Libraries -> add external Jars.

And I'm sorry I don't know about game programming, this is just a suggestion: make sure your engine fits what Android supports. For example Android doesn't support javax.imageio. If not, the app can be compiled with external jars, but can be crashed in runtime.