UML class diagrams show relationships between Java classes and details of each class member.
Use WinA&D or MacA&D to draw UML models enriched with Java language specific details, then generate Java class declarations and function frames with one mouse click. Namespaces in WinA&D provide the structure needed to represent Java packages.
Import that file into WinA&D to generate UML class models. Classes can be partitioned into diagrams based on package structure.
The automated process takes just minutes to create models from code for a large project.