安装AdoptOpenJDK 11并删除旧的java 8？

Question

我在我的centos7机器上安装了Java8，我想切换到adadtopenjdk11。我已经通过rpm安装了它，但不知道它在哪个目录下。which java显示了旧的java8位置。

我不再需要Java 8了，怎么才能换成11呢？

[user@centos ~]$ java -version
openjdk version "1.8.0_292"
OpenJDK Runtime Environment (build 1.8.0_292-b10)
OpenJDK 64-Bit Server VM (build 25.292-b10, mixed mode)

[user@centos ~]$ sudo yum install adoptopenjdk-11-hotspot
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
AdoptOpenJDK                                                                                 | 1.4 kB  00:00:00
base                                                                                         | 3.6 kB  00:00:00
epel                                                                                         | 4.7 kB  00:00:00
extras                                                                                       | 2.9 kB  00:00:00
jenkins                                                                                      | 2.9 kB  00:00:00
nhn-epel                                                                                     | 2.5 kB  00:00:00
nhn-epel-noarch                                                                              | 2.5 kB  00:00:00
update                                                                                       | 2.9 kB  00:00:00
AdoptOpenJDK/7/x86_64/primary                                                                |  58 kB  00:00:01
AdoptOpenJDK                                                                                                234/234
Resolving Dependencies
--> Running transaction check
---> Package adoptopenjdk-11-hotspot.x86_64 0:11.0.11+9-3 will be installed
--> Finished Dependency Resolution

Dependencies Resolved

====================================================================================================================
 Package                              Arch                Version                   Repository                 Size
====================================================================================================================
Installing:
 adoptopenjdk-11-hotspot              x86_64              11.0.11+9-3               AdoptOpenJDK              184 M

Transaction Summary
====================================================================================================================
Install  1 Package

Total download size: 184 M
Installed size: 306 M
Is this ok [y/d/N]: y
Downloading packages:
warning: /home1/sys-var/cache/yum/x86_64/7/AdoptOpenJDK/packages/adoptopenjdk-11-hotspot-11.0.11+9-3.x86_64.rpm: Header V4 RSA/SHA1 Signature, key ID 74885c03: NOKEY
Public key for adoptopenjdk-11-hotspot-11.0.11+9-3.x86_64.rpm is not installed
adoptopenjdk-11-hotspot-11.0.11+9-3.x86_64.rpm                                               | 184 MB  00:02:38
Retrieving key from https://adoptopenjdk.jfrog.io/adoptopenjdk/api/gpg/key/public
Importing GPG key 0x74885C03:
 Userid     : "AdoptOpenJDK (used for publishing RPM and DEB files) <adoptopenjdk@gmail.com>"
 Fingerprint: 8ed1 7af5 d7e6 75eb 3ee3 bce9 8ac3 b291 7488 5c03
 From       : https://adoptopenjdk.jfrog.io/adoptopenjdk/api/gpg/key/public
Is this ok [y/N]: y
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
  Installing : adoptopenjdk-11-hotspot-11.0.11+9-3.x86_64                                                       1/1
  Verifying  : adoptopenjdk-11-hotspot-11.0.11+9-3.x86_64                                                       1/1

Installed:
  adoptopenjdk-11-hotspot.x86_64 0:11.0.11+9-3

Complete!

Answer 1

尝试使用update-alternatives --config java，它将向您显示已安装jdks的列表，您可以选择哪个jdks作为默认jdks：

[root@host /]# update-alternatives --config java

There are 2 programs which provide 'java'.

  Selection    Command
-----------------------------------------------
*+ 1           java-1.8.0-openjdk.x86_64 (/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.292.b10-1.el7_9.x86_64/jre/bin/java)
   2           /usr/lib/jvm/adoptopenjdk-11-hotspot/bin/java

Enter to keep the current selection[+], or type selection number: 2