The dreaded java.lang.NoClassDefFoundError

Question

I\'ve looked through many of the existing threads about this error, but still no luck. I\'m not even trying to package a jar or use any third-party packaging tools. I\'m s

Answer 1

Eclipse doesn't build executable java classes by default. Don't ask me why, but it probably has something to do with using their own tools.jar (somewhere in plugins/org.eclipse.core ?) so that Eclipse can run without a JDK.

You can usually go to your project bin directory and do:

java -cp . MyClass

But if you have external jars, Eclipse handles those internally in another weird way, so you'll need to add those too.