I have the code and I used javac *.java, because javac SimpleChat.java does not work (SwingBrowseListener and SwingQueryListener not found). javac *.java went well. But if I start up SimpleChat or BrowserApp (with java -cp . SimpleChat), I get the error message: Exception in thread "main" java.lang.NoClassDefFoundError: com/apple/dnssd/ResolveListener. I think the ResolveListener is in the .lib file. I even put this file in the . dir. But it is not working. If I use the .jar file, it is working. But I like to change code, so I need to use java(c). What Am I doing wrong?