http://www.ibm.com/developerworks/cn/java/j-lo-jse63/
http://blog.csdn.net/javafreely/article/details/9237799
http://www.open-open.com/lib/view/open1397359125465.html
http://maimode.iteye.com/blog/1354377
oracle官方文档
原文：http://www.cnblogs.com/zhao1949/p/6251039.html