umlet
http://www.umlet.com/
安装：
1.下载 com.umlet.plugin-14.2.zip
2. 解压 获得 com.umlet.plugin-14.2.jar
3. 置于 %eclipse_home%/plugins文件夹下
4. 重启eclipse
使用：http://www.umlet.com/faq.htm
How to start UMLet as Eclipse-Plugin?
Download the "com.umlet.plugin*.jar" file and copy it to Eclipse‘s plugin directory.
To create a new, empty UMLet diagram in Eclipse,
1. select a directory in the Eclipse resource navigator;
2. select "File/New/Other.." from the menu or the context menu; in the subsequent wizard,
3. select "UMLet/Diagram".
ModelGoon UML4Java
安装
http://www.modelgoon.org/?page_id=75
- Offline installation
- Using the Eclipse Marketplace Client (MPC)
- Using the Udapte Site : http://www.modelgoon.org/update
使用
http://www.modelgoon.org/?page_id=199
将java源码拖拽至窗口生成uml关系 
Class Diagram Tutorial
Select Classes from the Package Explorer and drop then on the Diagram. ModelGoon will compute and display its structural features and relationships with other classes already displayed.
Right clicking on the editor shows a context menu with view manipulation and export actions. As the diagram is not yet notified by the JDT when code modification occurs, it must be refreshed manually with the “Update Diagram” command. Zooming can also be performed by holding Control key any scrolling up or down with the mouse.
Right clicking on elements show deletion (only for classes) and navigation actions
Note : Only source files which are located inside a Java project source folder are supported by ModelGoon.