CentOS6.4 uninstall your own openjdk and install jdk1.6.21

#进入系统的terminal to view the current JDK version:

Shell>java-version

#查看安装包

Shell>rpm-qa|grep Java

#将上条命令查出来的结果卸载掉 and see if the uninstallation was successful

Shell>rpm-e--nodeps ... java ...

Sehll>java-version

#下载jdk安装包, Address: http://www.oracle.com/technetwork/java/javase/downloads/ Java-archive-downloads-javase6-419409.html#jdk-6u21-b07-oth-jpr

#将下载的文件jdk -6u21-linux-x64-rpm.bin into the/usr/java directory

Shell>mkdir/usr/java

Shell>cd/usr/java

#查看jdk Permissions for -6u21-linux-x64-rpm.bin

Shell>list-l

#修改为可执行

Shell>chmod 777 Jdk-6u21-linux-x64-rpm.bin

#执行安装包

Shell>./jdk-6u21-linux-x64-rpm.bin

#配置环境变量, edit the file/etc/profile, join in the last few lines

#export java_home=/usr/java/jdk1.6.0_21
#export classpath=.: $JAVA _home/jre/lib/rt.jar: $JAVA _home/lib/dt.jar: $JAVA _home/lib/tools.jar
#export path= $PATH: $JAVA _home/bin

Shell>vi/etc/profile

#使环境变量生效

Shell>source/etc/profile

#查看jdk版本

Shell>java-version

It's supposed to be a success here.

CentOS6.4 uninstall your own openjdk and install jdk1.6.21