I have tried

```

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

```

I won't work for my machine, I don't know why :(

Here is what I have

```

Last login: Sun Nov 29 12:15:35 on console

wlin@wlin-mbp ~ % /usr/libexec/java_home -V

Matching Java Virtual Machines (5):

12, x86_64: "OpenJDK 12" /Library/Java/JavaVirtualMachines/jdk-12.jdk/Contents/Home

11.0.9, x86_64: "Java SE 11.0.9" /Library/Java/JavaVirtualMachines/jdk-11.0.9.jdk/Contents/Home

11.0.6, x86_64: "AdoptOpenJDK 11" /Library/Java/JavaVirtualMachines/adoptopenjdk-11.jdk/Contents/Home

10.0.1, x86_64: "Java SE 10.0.1" /Library/Java/JavaVirtualMachines/jdk-10.0.1.jdk/Contents/Home

1.8.0_181, x86_64: "Java SE 8" /Library/Java/JavaVirtualMachines/jdk1.8.0_181.jdk/Contents/Home

/Library/Java/JavaVirtualMachines/jdk-12.jdk/Contents/Home

wlin@wlin-mbp ~ % export JAVA_HOME=`/usr/libexec/java_home -v 11`

wlin@wlin-mbp ~ % java -version

java version "1.8.0_181"

Java(TM) SE Runtime Environment (build 1.8.0_181-b13)

Java HotSpot(TM) 64-Bit Server VM (build 25.181-b13, mixed mode)

```