1.判断虚拟机位数和版本
//32位 java -version java version "1.7.0_79" Java(TM) SE Runtime Environment (build 1.7.0_79-b15) Java HotSpot(TM) Server VM (build 24.79-b02, mixed mode)
#64 位 java version "1.7.0_75" Java(TM) SE Runtime Environment (build 1.7.0_75-b13) Java HotSpot(TM) 64-Bit Server VM (build 24.75-b04, mixed mode)
原文：http://www.cnblogs.com/predisw/p/4977707.html