yum安装jdk和jdk配置以及实际安装位置

参考：

yum 安装 java_简单点-CSDN博客

然后继续查看java安装情况：

[root@Domi java-1.8.0]# find / -name java
/etc/pki/ca-trust/extracted/java
/etc/pki/java
/etc/alternatives/java
/etc/java
/var/lib/alternatives/java
/var/lib/docker/overlay2/4975faa492c278f456b16e507505129e21a025b0053ebe1e08befa521a6c3f68/diff/usr/local/openjdk-11/bin/java
/var/lib/docker/overlay2/09524fccefe9e3caff2388ca511e7b465e5e97756cf255a63349bd8fad1ed191/diff/etc/pki/ca-trust/extracted/java
/var/lib/docker/overlay2/09524fccefe9e3caff2388ca511e7b465e5e97756cf255a63349bd8fad1ed191/diff/etc/pki/java
/var/lib/docker/overlay2/7f458c86e9142f73541d1c55be6bac239cb73e6e0f7ad9331e6216459faa17d3/diff/usr/share/java
/var/lib/docker/overlay2/246c06d0805a8e9da9b7bbd91e53995ca6b5109066b102769ca5fa95152860f0/merged/usr/share/java
/var/lib/docker/overlay2/735c235d89ce69a839523506b95e435ed3e0524bd9f0f3133a36bd4814684110/diff/usr/share/java
/usr/bin/java
/usr/lib/java
/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64/jre/bin/java
/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64/bin/java
/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64-slowdebug/jre/bin/java
/usr/lib/jvm/java
/usr/share/bash-completion/completions/java
/usr/share/java
/usr/share/javadoc/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4/api/java
/usr/share/javadoc/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4/api/org/omg/stub/java
/usr/share/javadoc/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4/jre/api/accessibility/jaccess/spec/com/sun/java
/usr/share/javadoc/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4/jre/api/plugin/dom/com/sun/java
/usr/share/javadoc/java

发现java的安装在/usr/lib/jvm

[root@Domi etc]# cd /usr/lib/jvm

[root@Domi jvm]# ll
total 0
lrwxrwxrwx 1 root root  26 Oct 13 13:48 java -> /etc/alternatives/java_sdk
lrwxrwxrwx 1 root root  32 Oct 13 13:48 java-1.8.0 -> /etc/alternatives/java_sdk_1.8.0
lrwxrwxrwx 1 root root  40 Oct 13 13:48 java-1.8.0-openjdk -> /etc/alternatives/java_sdk_1.8.0_openjdk
drwxr-xr-x 9 root root 176 Oct 13 13:48 java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64
drwxr-xr-x 3 root root  17 Oct 13 13:47 java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64-slowdebug
lrwxrwxrwx 1 root root  34 Oct 13 13:48 java-openjdk -> /etc/alternatives/java_sdk_openjdk
lrwxrwxrwx 1 root root  21 Oct 13 13:47 jre -> /etc/alternatives/jre
lrwxrwxrwx 1 root root  27 Oct 13 13:47 jre-1.8.0 -> /etc/alternatives/jre_1.8.0
lrwxrwxrwx 1 root root  35 Oct 13 13:47 jre-1.8.0-openjdk -> /etc/alternatives/jre_1.8.0_openjdk
lrwxrwxrwx 1 root root  51 Jul 22 01:19 jre-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64 -> java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64/jre
lrwxrwxrwx 1 root root  61 Jul 22 01:19 jre-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64-slowdebug -> java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64-slowdebug/jre
lrwxrwxrwx 1 root root  29 Oct 13 13:47 jre-openjdk -> /etc/alternatives/jre_openjdk

发现软连接到同一个目录下：/etc/alternatives/

[root@Domi jvm]# cd /etc/alternatives/
[root@Domi alternatives]# ll
...
lrwxrwxrwx 1 root root 60 Oct 13 13:48 java_sdk -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64
lrwxrwxrwx 1 root root 60 Oct 13 13:48 java_sdk_1.8.0 -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64
lrwxrwxrwx 1 root root 60 Oct 13 13:48 java_sdk_1.8.0_openjdk -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64
lrwxrwxrwx 1 root root 60 Oct 13 13:48 java_sdk_openjdk -> /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64

发现实际软件到同一个目录：

java_sdk -> 				/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64
java_sdk_1.8.0 -> 			/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64
java_sdk_1.8.0_openjdk -> 	/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64
java_sdk_openjdk -> 		/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.302.b08-0.el8_4.x86_64

可以确定他们都是指向同一个安装包