Centos安装和配置jdk

在安装之前先检查一下自己的系统，rpm -qa|grep jdk 键入终端，查看安装了多少jdk 

如果没有直接跳到下载jdk那一步骤，如果有比如果我的

java-1.7.0-openjdk-devel-1.7.0.141-2.6.10.1.el6_9.x86_64

java-1.7.0-openjdk-javadoc-1.7.0.141-2.6.10.1.el6_9.noarch

java-1.7.0-openjdk-1.7.0.141-2.6.10.1.el6_9.x86_64

java-1.7.0-openjdk-demo-1.7.0.141-2.6.10.1.el6_9.x86_64

java-1.7.0-openjdk-src-1.7.0.141-2.6.10.1.el6_9.x86_64

建议先删除

yum remove xxx

例如

yum remove java-1.7.0-openjdk-devel-1.7.0.141-2.6.10.1.el6_9.x86_64

然后安装jdk

1)下载安装jdk

JDK下载官网

http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

下载后上传到服务器（目录可自定义）

# rpm -ivh jdk-8u131-linux-x64.rpm

Preparing...               ########################################### [100%]

1:jdk1.8.0_113          ########################################### [100%]

Unpacking JAR files...

tools.jar...

plugin.jar...

javaws.jar...

deploy.jar...

rt.jar...

jsse.jar...

charsets.jar...

localedata.jar...

# java -version

java version"1.8.0_131"

Java(TM) SE Runtime Environment (build 1.8.0_111-b14)

Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode)

# vim

/etc/profile添加jdk环境变量

exportJAVA_HOME=/usr/java/jdk1.8.0_131

export CLASSPATH=.:$JAVA_HOME/jre/lib/rt.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

export PATH=$PATH:$JAVA_HOME/bin

# source /etc/profile