What's the point of JAVA_HOME environment variable

Question

What is the point of setting JAVA_HOME environmental variable when the only thing you have to set is the Path variable to call java from the command line, which is the primary purpose, right ?

There wouldn't be much point if that was all it was used for. Other programs use it, though the `java` on the path is usually enough. — Peter Lawrey, Feb 01 '16 at 13:41
@PeterLawrey What are other uses for those paths and variables other than to be able to invoke an executable through command line from any directory ? — Shady Programmer, Feb 01 '16 at 17:40
Some programs use JAVA_HOME is their startup script e.g. IntelliJ does. — Peter Lawrey, Feb 02 '16 at 01:21

codeMan · Accepted Answer · 2016-02-01T13:54:08.727

3

JAVA_HOME is just a convention, usually used by Java EE app servers like Tomcat and build tools such as Gradle to find where Java lives.

You could also use JAVA_HOME to set the PATH variable, something like this..

%JAVA_HOME%\bin;

So that you dont have to meddle with PATH variable every time, if you have to switch between two JDKs or two JREs of different versions

edited Feb 01 '16 at 13:54

answered Feb 01 '16 at 13:46

codeMan

5,730
3
27
51

score 2 · Answer 2 · answered Feb 01 '16 at 13:42

2

Some application takes JAVA_HOME to execute/configure themselves instead of using the java executable in the PATH: tomcat, maven, weblogic, eclipse, etc...

So it's a good idea to have this variable properly set.

answered Feb 01 '16 at 13:42

jfcorugedo

9,793
8
39
47

but that's what my question is about: if those applications can see java in the PATH what's the point ? If JAVA_HOME and PATH are pointing to the same executable? – Shady Programmer Feb 01 '16 at 13:52
1

@ShadyProgrammer What if they don't? I believe I have at least two Java installations on my laptop, what if I want to switch which one is used without messing with $PATH? – Dan Lowe Feb 01 '16 at 13:56
Okay I've got you :) Thank you – Shady Programmer Feb 01 '16 at 13:59
1

That's. If you have some Java versions, JAVA_HOME is an easy way to switch from one to another. – jfcorugedo Feb 01 '16 at 14:01

score 1 · Answer 3 · answered Feb 01 '16 at 13:48

1

IMO this is a unix thing where the OS's files are saved. Windows is totally different. But since Java is installed into Program files in Windows it doesn't make sense either.

answered Feb 01 '16 at 13:48

Micromega

12,486
7
35
72

What's the point of JAVA_HOME environment variable

3 Answers3