Linux安装JDK完整步骤
1、检查一下系统中的jdk版本
[root@localhost software]# java -version显示：
[root@localhost ~]# java -version
openjdk version "1.8.0_262"
OpenJDK Runtime Environment (build 1.8.0_262-b10)
OpenJDK 64-Bit Server VM (build 25.262-b10, mixed mode)
[root@localhost ~]#
2、检测jdk安装包
[root@localhost software]# rpm -qa | grep java显示：
[root@localhost ~]# rpm -qa | grep java
javassist-3.16.1-10.el7.noarch
tzdata-java-2020a-1.el7.noarch
javapackages-tools-3.4.1-11.el7.noarch
javamail-1.4.6-8.el7.noarch
pki-base-java-10.5.18-7.el7.noarch
java-1.7.0-openjdk-1.7.0.261-2.6.22.2.el7_8.x86_64
java-1.8.0-openjdk-1.8.0.262.b10-1.el7.x86_64
java-1.8.0-openjdk-headless-1.8.0.262.b10-1.el7.x86_64
nuxwdog-client-java-1.0.5-1.el7.x86_64
java-1.7.0-openjdk-headless-1.7.0.261-2.6.22.2.el7_8.x86_64
python-javapackages-3.4.1-11.el7.noarch
[root@localhost ~]#
3、卸载openjdk
[root@localhost ~]# rpm -e --nodeps tzdata-java-2020a-1.el7.noarch
[root@localhost ~]# rpm -e --nodeps java-1.7.0-openjdk-1.7.0.261-2.6.22.2.el7_8.x86_64
[root@localhost ~]# rpm -e --nodeps java-1.8.0-openjdk-1.8.0.262.b10-1.el7.x86_64
[root@localhost ~]# rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.262.b10-1.el7.x86_64
[root@localhost ~]# rpm -e --nodeps java-1.7.0-openjdk-headless-1.7.0.261-2.6.22.2.el7_8.x86_64
或者使用
[root@localhost jvm]# yum remove *openjdk*之后再次输入rpm -qa | grep java 查看卸载情况：
javassist-3.16.1-10.el7.noarch
javapackages-tools-3.4.1-11.el7.noarch
javamail-1.4.6-8.el7.noarch
pki-base-java-10.5.18-7.el7.noarch
nuxwdog-client-java-1.0.5-1.el7.x86_64
python-javapackages-3.4.1-11.el7.noarch
[root@localhost ~]#
4、安装新的jdk
首先到jdk官网上下载你想要的jdk版本，下载完成之后将需要安装的jdk安装包放到Linux系统指定的文件夹下，并且命令进入该文件夹下：
官网下载最新稳定JDK：https://www.oracle.com/java/technologies/oracle-java-archive-downloads.html
注意：文件夹或文件没有执行权限时，记得修改其权限
[root@localhost Desktop]# pwd
/root/Desktop
[root@localhost Desktop]# ll
total 1860
-rw-r--r--. 1 root root 1904640 May 18 09:27 jdk-8u331-linux-i586.tar.gz
[root@localhost Desktop]#
解压 jdk-8u131-linux-x64.tar.gz安装包
[root@localhost software]# mkdir -p /usr/lib/jvm
[root@localhost Desktop]# chmod 777 /usr/lib/jvm [root@localhost software]# tar -zxvf jdk-8u131-linux-x64.tar.gz -C /usr/lib/jvm
[root@localhost Desktop]# pwd /root/Desktop [root@localhost Desktop]# ll total 1860 -rwxrwxrwx. 1 root root 1904640 May 18 09:27 jdk-8u331-linux-i586.tar.gz [root@localhost Desktop]# tar -zxvf jdk-8u331-linux-i586.tar.gz -C /usr/lib/jvm jdk1.8.0_331/ jdk1.8.0_331/COPYRIGHT jdk1.8.0_331/LICENSE jdk1.8.0_331/README.html jdk1.8.0_331/THIRDPARTYLICENSEREADME.txt jdk1.8.0_331/bin/ jdk1.8.0_331/bin/java-rmi.cgi jdk1.8.0_331/bin/appletviewer jdk1.8.0_331/bin/extcheck jdk1.8.0_331/bin/idlj jdk1.8.0_331/bin/jar jdk1.8.0_331/bin/jarsigner jdk1.8.0_331/bin/javac jdk1.8.0_331/bin/javadoc jdk1.8.0_331/bin/javah jdk1.8.0_331/bin/javap jdk1.8.0_331/bin/jdeps jdk1.8.0_331/bin/jconsole jdk1.8.0_331/bin/jdb jdk1.8.0_331/bin/jhat jdk1.8.0_331/bin/jinfo jdk1.8.0_331/bin/jmap jdk1.8.0_331/bin/jps jdk1.8.0_331/bin/jrunscript jdk1.8.0_331/bin/jjs jdk1.8.0_331/bin/jsadebugd jdk1.8.0_331/bin/jstack jdk1.8.0_331/bin/jstat jdk1.8.0_331/bin/jstatd jdk1.8.0_331/bin/keytool jdk1.8.0_331/bin/native2ascii jdk1.8.0_331/bin/policytool jdk1.8.0_331/bin/schemagen jdk1.8.0_331/bin/rmic jdk1.8.0_331/bin/serialver jdk1.8.0_331/bin/xjc jdk1.8.0_331/bin/wsgen jdk1.8.0_331/bin/wsimport jdk1.8.0_331/bin/orbd jdk1.8.0_331/bin/servertool jdk1.8.0_331/bin/tnameserv jdk1.8.0_331/bin/pack200 jdk1.8.0_331/bin/rmid jdk1.8.0_331/bin/rmiregistry jdk1.8.0_331/bin/jcmd jdk1.8.0_331/bin/java jdk1.8.0_331/bin/unpack200 jdk1.8.0_331/bin/javaws jdk1.8.0_331/bin/jcontrol jdk1.8.0_331/bin/ControlPanel jdk1.8.0_331/bin/jvisualvm jdk1.8.0_331/bin/javafxpackager jdk1.8.0_331/bin/javapackager jdk1.8.0_331/include/ jdk1.8.0_331/include/jdwpTransport.h jdk1.8.0_331/include/jni.h jdk1.8.0_331/include/jvmti.h jdk1.8.0_331/include/jvmticmlr.h jdk1.8.0_331/include/jawt.h jdk1.8.0_331/include/classfile_constants.h jdk1.8.0_331/include/linux/ jdk1.8.0_331/include/linux/jni_md.h jdk1.8.0_331/include/linux/jawt_md.h jdk1.8.0_331/jre/ jdk1.8.0_331/jre/bin/ jdk1.8.0_331/jre/bin/keytool jdk1.8.0_331/jre/bin/jjs jdk1.8.0_331/jre/bin/policytool jdk1.8.0_331/jre/bin/orbd jdk1.8.0_331/jre/bin/servertool jdk1.8.0_331/jre/bin/tnameserv jdk1.8.0_331/jre/bin/pack200 jdk1.8.0_331/jre/bin/rmid jdk1.8.0_331/jre/bin/rmiregistry jdk1.8.0_331/jre/bin/java jdk1.8.0_331/jre/bin/unpack200 jdk1.8.0_331/jre/bin/javaws jdk1.8.0_331/jre/bin/jcontrol jdk1.8.0_331/jre/bin/ControlPanel jdk1.8.0_331/jre/lib/ jdk1.8.0_331/jre/lib/i386/ jdk1.8.0_331/jre/lib/i386/libjsig.so jdk1.8.0_331/jre/lib/i386/server/ jdk1.8.0_331/jre/lib/i386/server/libjvm.so gzip: stdin: unexpected end of file tar: Unexpected EOF in archive tar: Unexpected EOF in archive tar: Error is not recoverable: exiting now [root@localhost Desktop]#
5、设置环境变量
修改配置文件/etc/profile，配置JDK相关的环境变量
记得备份下/etc/profile文件
[root@localhost jvm]# cd /home/
[root@localhost home]# mkdir Backup
[root@localhost home]# cp /etc/profile /home/Backup/
[root@localhost home]# ll ./Backup/
total 4
-rw-r--r--. 1 root root 1854 May 18 10:08 profile
[root@localhost home]#
[root@localhost home]# cd /usr/lib/jvm [root@localhost jvm]# pwd /usr/lib/jvm [root@localhost jvm]# ll total 0 drwxr-xr-x. 5 10143 10143 129 Mar 10 19:30 jdk1.8.0_331 [root@localhost jvm]#
[root@localhost software]# vim /etc/profile在最前面添加：
export JAVA_HOME=/usr/lib/jvm/jdk1.8.0_331 export JRE_HOME=${JAVA_HOME}/jre export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib export PATH=${JAVA_HOME}/bin:$PATH
6、执行profile文件
[root@localhost software]# source /etc/profile这样可以使配置不用重启即可立即生效。
7、检查新安装的jdk
[root@localhost software]# java -version显示：
java version "1.8.0_131" Java(TM) SE Runtime Environment (build 1.8.0_131-b11) Java HotSpot(TM) 64-Bit Server VM (build 25.131-b11, mixed mode)
到此为止，整个安装过程结束。
8、问题处理
如果报错，可能是由于64位系统中安装了32位的程序，所以重新下包操作上面流程即可。
9、查看Linux内核版本命令，两种方法都可以
输入：cat /proc/version
输入：uname -a