查看是否有内置的java环境:
[root@localhost ~]# java -version java version "1.7.0_45" OpenJDK Runtime Environment (rhel-2.4.3.3.el6-x86_64 u45-b15) OpenJDK 64-Bit Server VM (build 24.45-b08, mixed mode)查看已安装的java:
[root@localhost ~]# rpm -qa | grep java java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64 tzdata-java-2013g-1.el6.noarch java-1.6.0-openjdk-1.6.0.0-1.66.1.13.0.el6.x86_64分别执行命令yum删除以上3个:
[root@localhost ~]# yum remove java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64 [root@localhost ~]# yum remove java-1.6.0-openjdk-1.6.0.0-1.66.1.13.0.el6.x86_64 [root@localhost ~]# yum remove tzdata-java-2013g-1.el6.noarch或者通过rpm -e删除:
[root@localhost ~]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64 [root@localhost ~]# rpm -e --nodeps java-1.6.0-openjdk-1.6.0.0-1.66.1.13.0.el6.x86_64 [root@localhost ~]# rpm -e --nodeps tzdata-java-2013g-1.el6.noarch例如,下面是删除java 1.7时的过程:
[root@localhost ~]# yum remove java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64 Loaded plugins: fastestmirror, refresh-packagekit, security Setting up Remove Process Resolving Dependencies --> Running transaction check -->xxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxx xxxxxxxxxx Installed size: 90 M Is this ok [y/N]: y (屏幕停在这里时输入y) Downloading Packages: Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Erasing : 1:java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64 1/1 Verifying : 1:java-1.7.0-openjdk-1.7.0.45-2.4.3.3.el6.x86_64 1/1 Removed: java-1.7.0-openjdk.x86_64 1:1.7.0.45-2.4.3.3.el6 Complete!可通过命令确认是否删除成功:
[root@localhost ~]# java -bash: /usr/bin/java: 没有那个文件或目录 [root@localhost ~]# javac -bash: javac: command not found [root@localhost ~]# rpm -qa | grep java 不输出信息================================================================================== 安装java8 这里我下载的是压缩包,进行离线安装 官方下载地址:http://download.oracle.com/otn-pub/java/jdk/8u111-b14/jdk-8u111-linux-x64.tar.gz 将安装包放到/usr/local目录下后 命令进入到local目录:
[root@localhost local]# cd /usr/local/查看目录下的文件:
[root@localhost local]# ls bin games jdk-8u111-linux-x64.tar.gz lib libexec share etc include lib64 sbin src
解压
jdk-8u111-linux-x64.tar.gz:
[root@localhost local]# tar –xzvf jdk-8u111-linux-x64.tar.gz
获取解压后java目录绝对路径:
[root@localhost local]# cd jdk1.8.0_111/ [root@localhost jdk1.8.0_111]# pwd /usr/local/jdk1.8.0_111配置环境变量:
[root@localhost local]# vi /etc/profile在export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL
下面添加:
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL export JAVA_HOME=/usr/local/jdk1.8.0_111 export PATH=$JAVA_HOME/bin:$PATH保存并退出后执行命令source /etc/profile使修改的profile文件生效
[root@localhost jdk1.8.0_111]# source /etc/profile输入java,javac验证配置,到此处java环境配置完成。
[root@localhost local]# tar –xzvf jdk-8u111-linux-x64.tar.gz获取解压后java目录绝对路径:
[root@localhost local]# cd jdk1.8.0_111/ [root@localhost jdk1.8.0_111]# pwd /usr/local/jdk1.8.0_111配置环境变量:
[root@localhost local]# vi /etc/profile在export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL 下面添加:
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL export JAVA_HOME=/usr/local/jdk1.8.0_111 export PATH=$JAVA_HOME/bin:$PATH保存并退出后执行命令source /etc/profile使修改的profile文件生效
[root@localhost jdk1.8.0_111]# source /etc/profile输入java,javac验证配置,到此处java环境配置完成。