Setting up JAVA_HOME in Ubuntu to point to Window's JAVA

I tried to run Kafka on CMD in Windows and it's very unstable , constantly giving errors. Then I came across this post, which suggests installing Ubuntu and run Kafka from there.

I have installed Ubuntu successfully. Given that I have already defined JAVA_HOME=C:\Program Files\Java\jdk1.8.0_231 as one of the environmental variables and CMD recognizes this variable but Ubuntu does not, I am wondering how to make Ubuntu recognize this because at the moment, when i typed java -version, Ubuntu returns command not found.

Update: Please note that I have to have Ubuntu's JAVA_HOME pointing to the evironmental variable JAVA_HOME defined in my Window system. Because my Java program in eclipse would need to talk to Kafka using the same JVM.

I have added the two lines below in my /etc/profile file. echo $JAVA_HOME returns the correct path. However, java -version returns a different version of Java installed on Ubuntu, not the one defined in the /etc/profile

export JAVA_HOME=mnt/c/Program\ Files/Java/jdk1.8.0_231
export PATH=$JAVA_HOME/bin:$PATH

CodePudding user response：

You have 2 issues. Firstly you omitted the "/" from the beginning of the environment variable so your JAVA_HOME would not work unless you cd / as "mnt" won't exist.

export JAVA_HOME=/mnt/c/Program\ Files/Java/jdk1.8.0_231
export PATH=$JAVA_HOME/bin:$PATH

Secondly, if you use a Windows JDK the executable is java.exe

java.exe -version

Also consider when using WSL that WSL1 is faster when accessing Windows OS disk - helpful if using java.exe, and that WSL2 is faster for Linux mount drives - and you may be better off using Linux binaries in favour of Windows binaries as suggested in your Kafka post.

CodePudding user response：

When the user logs in, the environment will be loaded from the /etc/profile and $HOME/.bashrc files. There are many ways to solve this problem. You can execute ex manually

export JAVA_HOME=/opt/jdk1.8.0_66
export JRE_HOME=$JAVA_HOME/jre
export CLASSPATH=.:$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH

or fix the configuration in /etc/profile or $HOME/.bashrc

export JAVA_HOME=/opt/jdk1.8.0_66
export JRE_HOME=$JAVA_HOME/jre
export CLASSPATH=.:$JAVA_HOME/lib:$JRE_HOME/lib:$CLASSPATH
export PATH=$JAVA_HOME/bin:$JRE_HOME/bin:$PATH

CodePudding user response：

You can edit /etc/profile, append

export JAVA_HOME=C:\Program Files\Java\jdk1.8.0_231

export PATH=$JAVA_HOME/bin:$PATH