在Linux中运行的免费实用程序，用于从Java源文件创建UML类图

I prefer to jot down UML-diagrams on paper and then implement them using Java. It would be nice to have a utility which could create UML-diagrams for me which I may share on-line and include in the digital documentation. In other words: I want to create UML diagrams from Java source code.I prefer to jot down UML-diagrams on paper and