get java_home value from servers with bash script

Question

I'm confused. I want find JAVA_HOME value in server and type this code in bash script.

ssh username@server "echo ${JAVA_HOME}"

and try

ssh username@server "echo $JAVA_HOME"

or

 ssh username@server 'echo $JAVA_HOME'

and all of they not worked;

I replace "JAVA_HOME" with "PATH" and it's work; I connect with ssh to server and try "echo $JAVA_HOME " and it's work. I think the problem is "_" and I don't know how fix it. please help me

Answer 1

Your approach is not feasible.

$JAVA_HOME will be interpreted to the variable value in localhost instead of the remote server.

Besides, executing by ssh is not a login shell, you will not get environment variables defined in /etc/profile