转载一个简单的粒子效果实现，便于学习粒子系统也可直接使用到自己的程序中。作者在他网站上做了个例子程序 http://www.jhlabs.com/java/particles.html-a simple particle system

Java 2D plot/graph applet. It displays the graph directly from the database using a socket server on a configurable port. The graph is scalable and configurable in HTML