Running J6 and J7 on the same box?

[ImAMacGuy]

Is there any ramifications to Running J6 and J7 on the same box? Will the apps know which to use? Should I even bother with J7?

[sgrall-pfg]

I haven't had any issues running both.

In order to completely update an existing Java 6 install to 7, you will need to install the Java 7 JDK, rather than the JRE. Java 6 on the Mac is actually the Java 6 JDK.

Many apps that refuse to work with the Java 7 JRE will work with Java 7 JDK. Some apps (like the Casper Suite/JSS) still seem to require Java 6 regardless.

[jarednichols]

Yes, you can run them both. It really depends on what your needs are.

[JPDyson]

For our builds, I believe we have to at this point; one piece of crap utility that demands Java 1.6 be present. No conflicts, best I can tell.

[CasperSally]

Are there any gotchas that you have to install one before the other?

On next year's image, I'm thinking of installing Java 7, not aware of any apps requiring 6. Just don't want to regret it if there's some gotcha if you need 6 it has to be installed before 7.

[ImAMacGuy]

@sgrall -- I cuoldn't find a JDK for J7... do you have a link handy?

[mm2270]

Here: http://www.oracle.com/technetwork/java/javase/downloads/index.html

The Oracle Java 7 JDK and JRE downloads are right next to each other on that page.

[sgrall-pfg]

I just discovered a caveat with Java 7 JDK--- the old JVMs are not automatically removed from /Library/Java/JavaVirtualMachines when you upgrade. I'm trying to find a way to script the removal of all but the newest as part of a policy. If any master scripters out there know of a way to remove all but the newest file in a folder, I'd appreciate the assistance!

@CasperSally--You can install Java 6 after installing Java 7 if necessary. Worked fine for me.

[sgrall-pfg]

Ok, this works to remove all but the newest Java 7 JVM:

ls -rd /Library/Java/JavaVirtualMachines/* | sed 1d | sudo xargs rm -R

It relies on the assumption that all JVM files will be named in such a way that the newest will be listed first when ls is applied in reverse order, which looks to be the case going forward...