用Java实现邮件传输，很经典的，值得一看的。-using Java-mail transmission, classic, visit the gallery.

source codes for art gallery problem in java

java可以直接调用这个类实现画图功能，但是使用这个类的前提是你的电脑已经装了GraphViz软件，你可以在http://www.graphviz.org/Gallery.php下载windows版本，装完后，找到dot.exe所在的路径，-java can call this class implements the drawing functions, but only if the use of this class is that your computer has installed