将以下命令添加到~/. .zshenv文件

export JAVA_HOME=`/usr/libexec/java_home -v 1.8` 

以下是我如何在我的Linux (Ubuntu / Mint伙伴)上做到这一点，我猜Mac也可以这样做。

安装和配置

步骤:

[Basic - part] Download jdk (the .tgz file) by hand. Uncompress & rename properly, at a proper location. e.g /mnt/star/program/java/jdk-1.8 Make a soft link, which will be changed to switch java version later. e.g ln -s /mnt/star/program/java/jdk-1.8 /mnt/star/program/java/java Thus /mnt/star/program/java/java is the soft link. Set JAVA_HOME in a start script. Could use file like /etc/profile.d/eric.sh, or just use ~/.bashrc. e.g JAVA_HOME=/mnt/star/program/java/java Then open a new bash shell. java -version should print the java version. [More version - part] Download & install more Java version, as need, similar as above steps. e.g /mnt/star/program/java/jdk-11 [Switch - part] In ~/.bashrc, define variable for various Java version. e.g _E_JAVA_HOME_11='/mnt/star/program/java/jdk-11' _E_JAVA_HOME_8='/mnt/star/program/java/jdk-8' # dir of default version, _E_JAVA_HOME_D=$_E_JAVA_HOME_8 In ~/.bashrc, define command to switch Java version. e.g ## switch java version, alias jv11="rm $JAVA_HOME; ln -s $_E_JAVA_HOME_11 $JAVA_HOME" alias jv8="rm $JAVA_HOME; ln -s $_E_JAVA_HOME_8 $JAVA_HOME" # default java version, alias jvd="rm $JAVA_HOME; ln -s $_E_JAVA_HOME_D $JAVA_HOME" alias jv="java -version" In terminal, source ~/.bashrc to make the changes take effect. Then could switch using the defined commands.

命令-从上面的config

命令:

jv11 切换到Java 11 jv8 切换到Java 8 jvd 切换到默认的Java版本，该版本由上面定义的_E_JAVA_HOME_D表示。 合资企业 显示java版本。

示例输出:

eric@eric-pc:~$ jv
java version "1.8.0_191"
Java(TM) SE Runtime Environment (build 1.8.0_191-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.191-b12, mixed mode)

eric@eric-pc:~$ jv11
eric@eric-pc:~$ jv
java version "11.0.1" 2018-10-16 LTS
Java(TM) SE Runtime Environment 18.9 (build 11.0.1+13-LTS)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11.0.1+13-LTS, mixed mode)

eric@eric-pc:~$ jvd
eric@eric-pc:~$ jv
java version "1.8.0_191"
Java(TM) SE Runtime Environment (build 1.8.0_191-b12)
Java HotSpot(TM) 64-Bit Server VM (build 25.191-b12, mixed mode)

eric@eric-pc:~$ 

机制

它通过改变软链接来切换，如JAVA_HOME。

Tips

在我的机器上手动安装jdk时，我保留次要版本，然后与主要版本做一个软链接，但没有次要版本。 如 //这是实际的目录， jdk1.8.0_191 //这是jdk1.8.0_191的软链接 jdk-8 //这是一个到jdk-8或jdk-11的软链接 java 我在~/中定义了命令别名。Bashrc，但是在单独的文件中定义变量。 我正在使用~/。Eric_var定义变量，~/。bashrc将源它(例如源$HOME/.eric_var)。

一个基于/usr/libexec/java_home的小鱼函数

function jhome
    set JAVA_HOME (/usr/libexec/java_home $argv)
    echo "JAVA_HOME:" $JAVA_HOME
    echo "java -version:"
    java -version
end

如果你不使用fish，你可以在bash中做类似的事情:

#!/bin/bash

jhome () {
  export JAVA_HOME=`/usr/libexec/java_home $@`
  echo "JAVA_HOME:" $JAVA_HOME
  echo "java -version:"
  java -version
}

然后在java do之间切换:

$> jhome           #switches to latest java
$> jhome -v 1.7    #switches to java 1.7
$> jhome -v 1.6    #switches to java 1.6

裁判:https://gist.github.com/kenglxn/1843d552dff4d4233271

JDK Switch脚本

我改编了上面@Alex的答案，并编写了以下代码来修复Java 9的代码。

$ cat ~/.jdk
#!/bin/bash

#list available jdks
alias jdks="/usr/libexec/java_home -V"
# jdk version switching - e.g. `jdk 6` will switch to version 1.6
function jdk() {
  echo "Switching java version $1";

  requestedVersion=$1
  oldStyleVersion=8
  # Set the version
  if [ $requestedVersion -gt $oldStyleVersion ]; then
    export JAVA_HOME=$(/usr/libexec/java_home -v $1);
  else
    export JAVA_HOME=`/usr/libexec/java_home -v 1.$1`;
  fi

  echo "Setting JAVA_HOME=$JAVA_HOME"

  which java
  java -version;
}

切换到Java 8

$ jdk 8
Switching java version 8
Setting JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home
/usr/bin/java
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)

切换到Java 9

$ jdk 9
Switching java version 9
Setting JAVA_HOME=/Library/Java/JavaVirtualMachines/jdk-9.0.1.jdk/Contents/Home
/usr/bin/java
java version "9.0.1"
Java(TM) SE Runtime Environment (build 9.0.1+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.1+11, mixed mode)

如果你用的是fish，而你用的是mac，你希望能够在JDK之间切换，那么下面对我来说适用于mac。

@kenglxn的答案对我不起作用，我发现它没有设置-g，这是全局的!

放在~/.config/fish/config.fish下面

alias j8="jhome  -v 1.8.0_162"
alias j9="jhome  -v 9.0.1"

function jhome
    set -g -x JAVA_HOME (/usr/libexec/java_home $argv)
    echo "JAVA_HOME:" $JAVA_HOME
    echo "java -version:"
    java -version
end

funcsave jhome

要了解您已安装的版本/次要版本，您可以执行以下操作:

/usr/libexec/java_home -V                                                                              579ms  Wed 14 Feb 11:44:01 2018
Matching Java Virtual Machines (3):
    9.0.1, x86_64:  "Java SE 9.0.1" /Library/Java/JavaVirtualMachines/jdk-9.0.1.jdk/Contents/Home
    1.8.0_162, x86_64:  "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_162.jdk/Contents/Home
    1.8.0_121, x86_64:  "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home

检查Java版本:Java -version

版本切换:https://devqa.io/brew-install-java/

开放的~ / . bash_profile

export JAVA_8_HOME=$(/usr/libexec/java_home -v1.8)

export JAVA_11_HOME=$(/usr/libexec/java_home -v11)

别名java8=“出口JAVA_HOME=$ java_8_homs” 别名java11=“出口JAVA_HOME=$ java_11_homs”

源~ / . bash_profile

当我们切换到java11或java8时，java -version命令没有显示正确的版本。

在这种情况下，使用mvn -version查看用于构建解决方案的正确java版本