- install The Graphical Editing Framework (GEF) first.
in Eclipse: Help>Install new software … > GEF - download AmaterasUML from https://en.osdn.jp/projects/amateras/releases/p4435
- unzip AmaterasUML_1.3.4.zip into ECLIPSE_PATH/plugins
- net.java.amateras.xstream_1.3.4.jar
- net.java.amateras.umleditor_1.3.4.jar
- net.java.amateras.umleditor.java_1.3.4.jar
- restart Eclipse.
- in Eclipse - File>New>AmaterasUML>…
Now you are able to create nice class-diagram by drag and drop.