An example that demonstrates using Scala object-nested classes in Java code in NetBeans IDE. NetBeans allows referencing nested class using the binary name, while Eclipse IDE does not allow this.
The issues with Eclipse Java are discussed on StackOverflow: http://stackoverflow.com/questions/10207149/scala-object-nested-classes-in-eclipse-java/
(Tested on Mac OS X Lion with Scala 2.9.2 installed, NetBeans 7.1)
Build the nested library in scala-lib directory using the build shell script build.sh. This will compile the mypackage/Outer.scala class and package into nested.jar.
Then open the netbeans-use project in NetBeans IDE. It will use the created nested.jar file. The mypackage.Main class references nested class mypackage.Outer$Middle$Inner successfully (which Eclipse IDE fails in a similar example).
If Scala library is available (hardcoded at /usr/share/scala-2.9.2/lib/scala-library.jar), the example can also be executed by selecting Run on the project: message Running is displayed in the output.