Find All Available JREs on Mac OS X from the Java Application Installer

Question

If a Java application requires a specific version of the JRE, then how can I check its availability on Mac OS X during installation?

Answer 1

It should be as simple as watching /System/Library/Frameworks/JavaVM.framework/Versions/

eg. from my car:

manoa:~ stu$ ll /System/Library/Frameworks/JavaVM.framework/Versions/ total 56 774077 lrwxr-xr-x 1 root wheel 5 Jul 23 15:31 1.3 -> 1.3.1 167151 drwxr-xr-x 3 root wheel 102 Jan 14 2008 1.3.1 167793 lrwxr-xr-x 1 root wheel 5 Feb 21 2008 1.4 -> 1.4.2 774079 lrwxr-xr-x 1 root wheel 3 Jul 23 15:31 1.4.1 -> 1.4 166913 drwxr-xr-x 8 root wheel 272 Feb 21 2008 1.4.2 168494 lrwxr-xr-x 1 root wheel 5 Feb 21 2008 1.5 -> 1.5.0 166930 drwxr-xr-x 8 root wheel 272 Feb 21 2008 1.5.0 774585 lrwxr-xr-x 1 root wheel 5 Jul 23 15:31 1.6 -> 1.6.0 747415 drwxr-xr-x 8 root wheel 272 Jul 23 10:24 1.6.0 167155 drwxr-xr-x 8 root wheel 272 Jul 23 15:31 A 776765 lrwxr-xr-x 1 root wheel 1 Jul 23 15:31 Current -> A 774125 lrwxr-xr-x 1 root wheel 3 Jul 23 15:31 CurrentJDK -> 1.5 manoa:~ stu$ 

Answer 2

This art can help: http://developer.apple.com/technotes/tn2002/tn2110.html
Summery:

 String javaVersion = System.getProperty("java.version"); if (javaVersion.startsWith("1.4")) { // New features for 1.4 }