查看 jdk 安装路径
[root@zh74 ~]# whereis javajava: /usr/local/java /opt/jdk1.8.0_144/bin/java /usr/local/java/bin/java[root@zh74 ~]# which java/opt/jdk1.8.0_144/bin/java[root@zh74 ~]# echo $JAVA_HOME/usr/local/java[root@zh74 ~]# echo $PATH/opt/jdk1.8.0_144/bin:/root/perl5/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/root/bin:/root/bin:/usr/local/mysql/bin:/usr/local/java/bin:/usr/local/java/bin如果是windows中,可以使用:set java_home:查看JDK安装路径java -version:查看JDK版本
卸载 旧版本的JDK
确定JDK的版本:
rpm -qa | grep jdkrpm -qa | grep gcj方法一、[root@zh74 opt]# lsjdk1.8.0_144 ORCLfmap[root@zh74 opt]# rm -rf jdk1.8.0_144/再去 /etc/profile 文件下将 jdk 的路径删除方法二、yum -y remove java对应版本方法三、 rpm -qa|grep jdkrpm -e --nodeps jdk 版本
安装 JDK
下载新版本的JDK
官方地址: /technetwork/java/javase/downloads/index.htm
[root@zh74 ~]# tar zxf jdk-10.0.1_linux-x64_bin.tar.gz [root@zh74 ~]# mv jdk-10.0.1 /usr/local/java配置环境变量[root@zh74 ~]# tail -4 /etc/profile#export JAVA_HOME=/usr/local/java#export PATH=$PATH:/usr/local/java/bin[root@zh74 ~]# source /etc/profile[root@zh74 ~]# java -versionjava version "10.0.1" -04-17Java(TM) SE Runtime Environment 18.3 (build 10.0.1+10)Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.1+10, mixed mode)