linux下rpm安装和卸载jdk

安装jdk-7u21：rpm -ivh rpm -ivh jdk-7u21-linux-x64.rpm

安装时出现以下错误，提示文件冲突，代表正在安装的jdk-7u21和已安装的jdk-7u79冲突：

file /etc/init.d/jexec from install of jdk-2000:1.7.0_21-fcs.x86_64 conflicts with file from package jdk-2000:1.7.0_79-fcs.x86_64

查看已安装的jdk：rpm -qa|grep jdk

卸载掉冲突的jdk：rpm -e --nodeps jdk-1.7.0_79-fcs.x86_64

从新安装jdk-7u21 ：rpm -ivh rpm -ivh jdk-7u21-linux-x64.rpm

查看当前安装的jdk：rpm -qa|grep jdk