Problem building imported java-source

[Lisa]

I have set up the following build-script:
C:\Programfiler\Java\jdk1.6.0\bin\javac.exe -g %r*.java

Everything works fine when importing a source directory consisting of only two java-files with no package-structure (just a test-application). But when importing a source directory with a package-structure that also have dependencies to additional libraries, I get several errors:

1. in folders not including any .java-files the build completes with exit code 2. How to ignore folders not including any .java-files?

2. package w.x.y.z does not exist. How to specify where to find packages to be imported? Is there another way to do this than adding them all to the classpath?

Thanks in advance.