[bash] update-alternatives 로 java 버전 변경하기

 

jdk 설치

## jdk 버전을 3개 설치한다
# yum install java-1.7.0-openjdk.x86_64
# yum install java-1.8.0-openjdk.x86_64
# yum install java-11-openjdk.x86_64

 

update-alternatives --config java 명령으로 java 버전을 변경한다

## 현재 java 버전은 8
# java -version
openjdk version "1.8.0_402"
OpenJDK Runtime Environment (build 1.8.0_402-b06)
OpenJDK 64-Bit Server VM (build 25.402-b06, mixed mode)

## 3을 입력해서 java 버전을 변경한다
# update-alternatives --config java
There are 3 programs which provide 'java'.

  Selection    Command
-----------------------------------------------
   1           java-1.7.0-openjdk.x86_64 (/usr/lib/jvm/java-1.7.0-openjdk-1.7.0.261-2.6.22.2.el7_8.x86_64/jre/bin/java)
*+ 2           java-1.8.0-openjdk.x86_64 (/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.402.b06-1.el7_9.x86_64/jre/bin/java)
   3           java-11-openjdk.x86_64 (/usr/lib/jvm/java-11-openjdk-11.0.22.0.7-1.el7_9.x86_64/bin/java)

Enter to keep the current selection[+], or type selection number: 3

## 변경된 java 버전은 11
# java -version
openjdk version "11.0.22" 2024-01-16 LTS
OpenJDK Runtime Environment (Red_Hat-11.0.22.0.7-1.el7_9) (build 11.0.22+7-LTS)
OpenJDK 64-Bit Server VM (Red_Hat-11.0.22.0.7-1.el7_9) (build 11.0.22+7-LTS, mixed mode, sharing)

 

대화형, 비대화형으로 변경하기

# 대화형으로 변경
sudo update-alternatives --config java

# 비대화형으로 변경 17
sudo update-alternatives --set java /usr/lib/jvm/java-17-openjdk-amd64/bin/java
sudo update-alternatives --set javac /usr/lib/jvm/java-17-openjdk-amd64/bin/javac

# 비대화형으로 변경 21
sudo update-alternatives --set java /usr/lib/jvm/java-21-openjdk-amd64/bin/java
sudo update-alternatives --set javac /usr/lib/jvm/java-21-openjdk-amd64/bin/javac