下载地址：Java 8, 11, 17, 21, 23 Download for Linux, Windows and macOS

安装 Java 8：下载完成后，双击 .dmg 文件，接着在打开的窗口中双击 .pkg 文件，按照安装向导完成安装。

vim ~/.bashrcexport JAVA_8_HOME=/Library/Java/JavaVirtualMachines/zulu-8.jdk/Contents/Homeexport JAVA_20_HOME=/Library/Java/JavaVirtualMachines/jdk-20.jdk/Contents/Homeexport JAVA_HOME=$JAVA_20_HOME# 切换 Java 版本的函数
switch_java() {if [ $1 = '8' ]; thenexport JAVA_HOME=$JAVA_8_HOMEelif [ $1 = '20' ]; thenexport JAVA_HOME=$JAVA_20_HOMEelseecho "不支持的 Java 版本。请输入 8 或 20。"fijava -version
}#switch_java 8
openjdk version "1.8.0_442"
OpenJDK Runtime Environment (Zulu 8.84.0.15-CA-macos-aarch64) (build 1.8.0_442-b06)
OpenJDK 64-Bit Server VM (Zulu 8.84.0.15-CA-macos-aarch64) (build 25.442-b06, mixed mode)#switch_java 20
java version "20.0.1" 2023-04-18
Java(TM) SE Runtime Environment (build 20.0.1+9-29)
Java HotSpot(TM) 64-Bit Server VM (build 20.0.1+9-29, mixed mode, sharing)