Error: JAVA_HOME is set to an invalid directory: /usr/lib/jvm/java-8-oracle/jre/bin/java when i run gradle command in terminal

Question

I am working in Ubuntu 16.04. I need to install gradle and the gradle is installed when i checked with sudo apt list --installed command but when i use gradle -version command it shows the following error, JAVA_HOME is set to an invalid directory: /usr/lib/jvm/java-8-oracle/jre/bin/java

In sudo vim /etc/environment file,

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games"
JAVA_HOME="/usr/lib/jvm/java-8-openjdk-amd64/"
http_proxy="http://username:password@IP:port no/"
https_proxy="https://IP:port no/"
ftp_proxy="ftp://IP:port no/"

I don't know where i made mistakes. Please help me.

Thanks.

Answer 1

On a 64bit openSuse 64 42.1 box;

readlink -f $(which java)

provided;

/usr/lib64/jvm/java-1.8.0-openjdk-1.8.0/jre/bin/java

But;

export JAVA_HOME=/usr/lib64/jvm/jre-1.8.0-openjdk

is the path that worked and allowed java emulator to run.

So i think we have to manually browse our file system and see what path to choose.

Answer 2

Today I faced this problem. I am using the default java that comes with your linux distro (so in my case, linux mint).

$ whereis java

This command gave me

java: /usr/bin/java /usr/share/java

So, I opened /user/bin. There was a link to Java. I right clicked it and selected follow original link. This lead me to /usr/lib/jvm/java-11-openjdk-amd64/bin/java. So now that I know where this java is, I opened my .bashrc file, and edited the JAVA_HOME. So for my case,

## My Custom variables
export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64
export PATH=$JAVA_HOME/bin:$PATH

This solved the problem.

Now if you are using some other java (say you downloaded from oracle and extracted the zip file ...), then you have to add that location. So for example, if your java is in /home/user/.sdkman/candidates/java/current, then

export JAVA_HOME=/home/user/.sdkman/candidates/java/current
export PATH=$JAVA_HOME/bin:$PATH