centos上安装jdk

一、准备工作 卸载OpenJDK1.查找需要卸载的OpenJDK [xsdbc@localhost ~]$ rpm -qa | grep openjdk | grep -v grep java-1.7.0-openjdk-1.7.0.75-2.5.4.2.el7_0.x86_64 java-1.6.0-openjdk-devel-1.6.0.34-1.13.6.1.el7_0.x86_64 java-1.7.0-openjdk-headless-1.7.0.75-2.5.4.2.el7_0.x86_64 java-1.6.0-openjdk-1.6.0.34-1.13.6.1.el7_0.x86_64 java-1.7.0-openjdk-devel-1.7.0.75-2.5.4.2.el7_0.x86_642.依次卸载 rpm -e –nodeps java-1.7.0-openjdk-1.7.0.75-2.5.4.2.el7_0.x86_64 rpm -e –nodeps java-1.6.0-openjdk-devel-1.6.0.34-1.13.6.1.el7_0.x86_64 rpm -e –nodeps java-1.7.0-openjdk-headless-1.7.0.75-2.5.4.2.el7_0.x86_64 rpm -e –nodeps java-1.6.0-openjdk-1.6.0.34-1.13.6.1.el7_0.x86_64 rpm -e –nodeps java-1.7.0-openjdk-devel-1.7.0.75-2.5.4.2.el7_0.x86_64 注：权限不足，请使用su root提权后再用。下载JDK  http://www.oracle.com/technetwork/java/javase/downloads/index.html  注：678我都下载了，准备都解压了，但只配置jdk7，其他两个版本备用。也方便日后切换使用。二、安装配置JDK7 1.解压安装jdk文件 tar -zxvf jdk-7u75-linux-x64.tar.gz mkdir /usr/java mv ./jdk1.7.0_75 /usr/java/jdk1.7.0_75 rm -rf ./jdk1.7.0_752.配置JDK7 编辑/etc/profile文件 vi /etc/profile 在/etc/profile文件尾部添加 export JAVA_HOME=/usr/java/jdk1.7.0_75 export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar export PATH=$PATH:$JAVA_HOME/bin使用source /etc/profile命令重新加载/etc/profile文件，使修改的内容在当前shell窗口中生效。（永久生效，重启系统或注销用户）三、测试 [xsdbc@localhost ~]$ java -version java version “1.7.0_75” Java™ SE Runtime Environment (build 1.7.0_75-b13) Java HotSpot™ 64-Bit Server VM (build 24.75-b04, mixed mode) OK!完成了～四、拓展 每次安装系统都要如此配置无疑是很讨厌的。技术男有义务让这些变得简单，将更多的时间留给美眉。程序猿不能容忍重复性工作，浪费生命。 来吧，编写脚本一次完成整个安装。

<!-- lang: shell -->
#!/bin/bash
# shell script to install jdk

# 1. remove openjdk if exists.

for i in $(rpm -qa | grep openjdk | grep -v grep)
do
echo "Deleting rpm -> "$i
rpm -e --nodeps $i
done

if [[ ! -z $(rpm -qa | grep jdk | grep -v grep) ]];
then
echo "-->Failed to remove the defult Jdk."
else

# 2.tar and install JDK(jdk-7u75-linux-x64.tar.gz)

tar -zxvf jdk-7u75-linux-x64.tar.gz
mkdir /usr/java
mv ./jdk1.7.0_75 /usr/java/jdk1.7.0_75
rm -rf ./jdk1.7.0_75

# 3. config /etc/profile

echo "export JAVA_HOME=/usr/java/jdk1.7.0_75" >>/etc/profile
echo -e 'export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar'>>/etc/profile
echo -e 'export PATH=$PATH:$JAVA_HOME/bin'>>/etc/profile

source /etc/profile

fi

原文链接:http://my.oschina.net/cennac/blog/373881