安装JDK

1.先解压JDK（这样可以减少切换JDK造成的时间）

 cp jdk-7u75-linux-x64.tar.gz /usr/local/iron/java  
  1. tar xvf  jdk-7u75-linux-x64.tar.gz  

2.配置环境变量

[root@localhost~]# vi /etc/profile 

export JAVA_HOME=/usr/local/iron/java/jdk1.7.0_79 
export JRE_HOME=/usr/local/iron/java/jdk1.7.0_79/jre  
export PATH=$PATH:/usr/local/iron/java/jdk1.7.0_79/bin  
export CLASSPATH=./:/usr/local/iron/java/jdk1.7.0_79/lib:/usr/local/iron/java/jdk1.7.0_79/jre/lib  

3.卸载原来的 OpenJDK

[root@tzrmyyhospital10 ~]# rpm -qa|grep java
java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64
java-1.6.0-openjdk-1.6.0.0-1.66.1.13.0.el6.x86_64
tzdata-java-2013g-1.el6.noarch
[root@tzrmyyhospital10 ~]# 
[root@tzrmyyhospital10 ~]# rpm -e --nodeps tzdata-java-2013g-1.el6.noarch
[root@tzrmyyhospital10 ~]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64
[root@tzrmyyhospital10 ~]# rpm -e --nodeps java-1.6.0-openjdk-1.6.0.0-1.66.1.13.0.el6.x86_64

4.让环境变量生效

source /etc/profile