JAVA_HOME Location on a Mac is no longer reliable

Ignition
1

This comes directly from ignition.sh:

# OSX always places Java in the same location so we can reliably set JAVA_HOME
if [ "$DIST_OS" = "macosx" ]
then
    if [ -z "$JAVA_HOME" ]; then
        JAVA_HOME="/Library/Java/Home"; export JAVA_HOME
    fi
fi

As of at least OS X 10.9 (and I think a bit earlier), if you install the Oracle version of Java (which you must do if you want Java 7) the install location for Java is:

/Library/Internet Plug-Ins/JavaAppletPlugin.plugin/Contents/Home

I’m not sure why [ -z "$JAVA_HOME" ]; evaluates true in this case as “echo $JAVA_HOME” yields the above path in my terminal (bash is far from my thing). In any case, modifying the shell script to use that path points Ignition at the 1.7 JRE.

2

This shell script is part of the JSW distribution… maybe we can check if they’ve got an updated vesion.

FWIW, the reliable way to get a value usable for JAVA_HOME on OS X (as of 10.9 or Java 7, anyway, not sure about earlier) is to execute /usr/libexec/java_home and use the result.

kevin-dev-mbp:~ kevin$ /usr/libexec/java_home 
/Library/Java/JavaVirtualMachines/jdk1.7.0_51.jdk/Contents/Home

I have this set in my ~/.profile

JAVA_HOME=$(/usr/libexec/java_home)

The wrapper’s shell script should probably do the same when JAVA_HOME isn’t set.

3

Looks like the main reason I am seeing this problem is that I downloaded the JRE for this machine which installs to the plug-in location, and which apparently no amount of export JAVA_HOME="… will remedy the /usr/libexec/java_home situation.

Lesson learned: always get the JDK even if you don’t plan to write a line of Java on that machine.