Using JDK that is bundled inside Android Studio as JAVA_HOME on Mac

Question

I tried to open Android Device Monitor and the Studio showed me this message =-O :

It surprised me, because how have I been able to develop Android apps if I didn't have any Java installed?! Actually, Android Studio comes with bundled JDK/JRE (located in /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home), but it is not found by the system: executed usr/libexec/java_home gives

Unable to find any JVMs matching version "(null)". No Java runtime present, try --request to install. 

Setting $JAVA_HOME to /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home did not help — source .bash_profile doesn't like that it's a directory.

QUESTION: I don't want to install new JDK if I already have one inside Android Studio. How do I set it as system default?

Answer 1

Add the correct string to .bash_profile (and reload with source .bash_profile):

1. MacOS versions before Big Sur: export JAVA_HOME=/Applications/Android\ Studio.app/Contents/jre/jdk/Contents/Home/.
2. Catalina, Big Sur, Mentere and above: export JAVA_HOME=/Applications/Android\ Studio.app/Contents/jre/Contents/Home

If you're using Catalina and above, you most probably use zsh as a shell instead of bash. In that case, add it to .zshrc or .zprofile instead of .bash_profile in your home directory.

Don't forget to restart the operating system after.

After that, running java -version gave this output and Java started to execute normally:

openjdk version "1.8.0_112-release" OpenJDK Runtime Environment (build 1.8.0_112-release-b06) OpenJDK 64-Bit Server VM (build 25.112-b06, mixed mode) 

As for the Android Device Monitor — it still demands this ancient JRE version 6.