Centos7安装jdk1.8(两种安装方式)
1，检查本机是否安装了jdk，安装了就不用安装了
命令如下：
[root@localhost ~]# java -version
-bash: java: 未找到命令
[root@localhost ~]#
注意：说明未安装
一，下载安装
JDK下载地址：
http://www.oracle.com/technetwork/java/javase/downloads/index.html
下载你自己需要的版本
3，使用rz命令上传，没有的可以下载：yum install lrzsz
3.1上传到 /home 目录下
[root@localhost ~]# yum install lrzsz --安装rz命令
[root@localhost ~]# cd /home --进入/home目录
[root@localhost home]#rz --上传
[root@localhost home]# tar -zxvf jdk-8u181-linux-x64.tar.gz --解压
如果觉得名字太长可以重新命名
[root@localhost home]# mv jdk1.8.0_181/ jdk1.8
[root@localhost home]#mkdir /usr/java --创建/java目录
[root@localhost home]# mv jdk1.8 /usr/java --转移到/usr/java目录下
配置环境变量
vim命令不能使用？？只能使用vi命令？
安装一下吧
[root@localhost home]#yum install vim
[root@localhost home]# vim /etc/profile
在export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE HISTCONTROL 之后新增以下三行
export JAVA_HOME=/usr/java/jdk1.8
export CLASSPATH=.:%JAVA_HOME%/lib/dt.jar:%JAVA_HOME%/lib/tools.jar
export PATH=$PATH:$JAVA_HOME/bin
使刚刚的配置文件生效
[root@localhost home]# source /etc/profile
测试jdk是否安装成功
[root@localhost home]# java -version
java version "1.8.0_191"
Java(TM) SE Runtime Environment (build 1.8.0_191-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.191-b12, mixed mode)
“出现以上说明成功”
二，命令安装
1，通过以下命令获得java JDK列表
[root@localhost huimou]# yum -y list java*
CentOS Linux 7 - AppStream 1.1 MB/s | 8.8 MB 00:07
CentOS Linux 7 - BaseOS 371 kB/s | 5.6 MB 00:15
CentOS Linux 7 - Extras 6.1 kB/s | 10 kB 00:01
可安装的软件包
java-1.8.0-openjdk.x86_64 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-accessibility.x86_64 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-demo.x86_64 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-devel.x86_64 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-headless.x86_64 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-headless-slowdebug.x86_64 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-javadoc.noarch 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-javadoc-zip.noarch 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-slowdebug.x86_64 1:1.8.0.302.b08-0.el8_4 appstream
java-1.8.0-openjdk-src.x86_64 1:1.8.0.302.b08-0.el8_4 appstream
java-11-openjdk.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-11-openjdk-demo.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-11-openjdk-devel.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-11-openjdk-headless.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-11-openjdk-javadoc.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-11-openjdk-javadoc-zip.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-11-openjdk-jmods.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-11-openjdk-src.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-11-openjdk-static-libs.x86_64 1:11.0.12.0.7-0.el8_4 appstream
java-atk-wrapper.x86_64 0.33.2-6.el8 appstream
javapackages-filesystem.noarch 5.3.0-1.module_el8.0.0+11+5b8c10bd appstream
javapackages-tools.noarch 5.3.0-1.module_el8.0.0+11+5b8c10bd appstream
[root@localhost huimou]#
2，通过yum安装JDK下载 java-1.8.0 可以选择自己需要的版本！！！
yum -y install java-1.8.0-openjdk*
3，等待安装完成
通过yum默认安装的路径为/usr/lib/jvm/java-版本号（如/usr/lib/jvm/java-1.8.0）
4，测试jdk是否安装成功
[root@localhost huimou]# java -version
openjdk version "1.8.0_302"
OpenJDK Runtime Environment (build 1.8.0_302-b08)
OpenJDK 64-Bit Server VM (build 25.302-b08, mixed mode)
