I want to design a Java application in UML with help of ArgoUML and would like to reuse SDK classes in it. Is such thing possible?
Based on the comment of Sean Mickey the correct answer is to add a Java profile to the project.
argouml-stats.tigris.org/documentation/manual-0.30/ch24s03.html
Right click on "Profile Configuration" -> "Manage Profiles..." -> "Java from Available Profiles to Active Profiles"