從Java應用程序安裝程序在Mac OS X上查找所有可用的JRE

Question

如果Java應用程序需要特定的JRE版本，那麼在安裝期間如何檢查其在Mac OS X上的可用性？

Answer 1

它應該是爲尋找/System/Library/Frameworks/JavaVM.framework/Versions/

例如簡單從我的機器：

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

這ARTICAL可能會有幫助： http://developer.apple.com/technotes/tn2002/tn2110.html
綜述：

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