引用外部Java和Android库

Question

I am trying to reference a Java and an Android library (that I created) to use within my Android application built in Eclipse.

I am referencing the Java library via Properties-->Java Build Path-->Projects-->Add.
I am referencing the Android library via Properties-->Android-->Library-->Add.

Both of these are shown within the windows after adding them. I also moved the Java library to the top of the list within Properties-->Java Build Path-->Order and Export.

My project compiles fine but when I run the application on my device I get a NoClassDefFoundError from the Java library. The class is in there and should work.

Did I miss something that I need to link in order to get this running correctly?

Answer 1

I am referencing the Java library via Properties-->Java Build Path-->Projects-->Add.

This is incorrect. Please undo that, and then copy the JAR into libs/ within your project. If you are on the R22 or higher version of the tools, you may also need to go to "Order and Export" in your build path dialog and check "Android Private Libraries" .

What you did only added the JAR to the compile path. Putting the JAR in libs/ will add it to the compile path and package the JAR's contents in your APK, so those classes are available at runtime.