CentOS 7.5下Java环境的安装配置
1、查看系统中的java环境
[root@localhost ~]# java -version openjdk version “1.8.0_101″ OpenJDK Runtime Environment (build 1.8.0_101-b13) OpenJDK 64-Bit Server VM (build 25.101-b13, mixed mode)
进一步查看JDK信息：
[root@localhost ~]# rpm -qa | grep java javapackages-tools-3.4.1-11.el7.noarch java-1.8.0-openjdk-headless-1.8.0.101-3.b13.el7_2.x86_64 python-javapackages-3.4.1-11.el7.noarch tzdata-java-2016f-1.el7.noarch java-1.8.0-openjdk-1.8.0.101-3.b13.el7_2.x86_64
卸载 OpenJDK：rpm -e –nodeps
[root@localhost ~]# rpm -e –nodeps javapackages-tools-3.4.1-11.el7.noarch [root@localhost ~]# rpm -e –nodeps java-1.8.0-openjdk-headless-1.8.0.101-3.b13.el7_2.x86_64 [root@localhost ~]# rpm -e –nodeps python-javapackages-3.4.1-11.el7.noarch [root@localhost ~]# rpm -e –nodeps tzdata-java-2016f-1.el7.noarch [root@localhost ~]# rpm -e –nodeps java-1.8.0-openjdk-1.8.0.101-3.b13.el7_2.x86_64
2、安装jdk
下载jdk的rpm安装包上传到/usr/local/java
下载地址：http://www.Oracle.com/technetwork/java/javase/downloads/index.html
cd /usr/local/java 进入jdk所在的文件夹执行安装命令：
[root@localhost java]# rpm -ivh jdk-8u91-linux-x64.rpm 准备中… ################################# [100%]正在升级/安装… 1:jdk1.8.0_91-2000:1.8.0_91-fcs ################################# [100%]Unpacking JAR files… tools.jar… plugin.jar… javaws.jar… deploy.jar… rt.jar… jsse.jar… charsets.jar… localedata.jar… jfxrt.jar…
不报错就安装成功
验证：
[root@localhost java]# java -versionjava version “1.8.0_91″Java(TM) SE Runtime Environment (build 1.8.0_91-b14)Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode)
3、环境变量设置
修改系统环境变量文件vi + /etc/profile
[root@localhost java]# vi + /etc/profile
fi
HOSTNAME=`/usr/bin/hostname 2>/dev/null`HISTSIZE=1000if [ “$HISTCONTROL” = “ignorespace” ] ; then export HISTCONTROL=ignorebothelse export HISTCONTROL=ignoredupsfi
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL
JAVA_HOME=/usr/java/jdk1.8.0_91JRE_HOME=/usr/java/jdk1.8.0_91/jrePATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/binCLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar:$JRE_HOME/libexport JAVA_HOME JRE_HOME PATH CLASSPATH
# By default, we want umask to get set. This sets it for login shell# Current threshold for system reserved uid/gids is 200# You could check uidgid reservation validity in# /usr/share/doc/setup-*/uidgid fileif [ $UID -gt 199 ] && [ “`id -gn`” = “`id -un`” ]; then umask 002else umask 022fi
for i in /etc/profile.d/*.sh ; do if [ -r “$i” ]; then if [ “${-#*i}” != “$-” ]; then . “$i” else . “$i” >/dev/null fi fidone
unset iunset -f pathmunge”/etc/profile” 82L, 1972C
红色字体的为添加的设置，通常java安装在/usr/java/目录下
使修改生效[root@localhost ~]# source /etc/profile //使修改立即生效
验证配置：
[root@localhost java]# echo $PATH/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/usr/java/jdk1.8.0_91/bin:/usr/java/jdk1.8.0_91/jre/bin
这样就完成的对整个java环境的配置
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