MacのJava環境

JAVA_HOME

いろいろなバージョンのJDKがインストールされているようですがJAVA_HOMEを設定しても、なぜか切り替えできません。
ちょっと不思議です。

$ ls -l /System/Library/Frameworks/JavaVM.framework/Versions/
total 64
lrwxr-xr-x  1 root  wheel    5 12  8 23:16 1.3 -> 1.3.1
drwxr-xr-x  3 root  wheel  102  7 21  2009 1.3.1
lrwxr-xr-x  1 root  wheel   10 12  8 23:16 1.4 -> CurrentJDK
lrwxr-xr-x  1 root  wheel   10 12  8 23:16 1.4.2 -> CurrentJDK
lrwxr-xr-x  1 root  wheel   10 12  8 23:16 1.5 -> CurrentJDK
lrwxr-xr-x  1 root  wheel   10 12  8 23:16 1.5.0 -> CurrentJDK
lrwxr-xr-x  1 root  wheel    5 12  8 23:16 1.6 -> 1.6.0
drwxr-xr-x  8 root  wheel  272  9  2 22:47 1.6.0
drwxr-xr-x  9 root  wheel  306 12  8 23:16 A
lrwxr-xr-x  1 root  wheel    1 12  8 23:16 Current -> A
lrwxr-xr-x  1 root  wheel    3 12  8 23:16 CurrentJDK -> 1.6
$ echo $JAVA_HOME
/System/Library/Frameworks/JavaVM.framework/Versions/1.4/Home
$ echo $PATH
/System/Library/Frameworks/JavaVM.framework/Versions/1.4/Home/bin:以下省略
$ type java
java is hashed (/System/Library/Frameworks/JavaVM.framework/Versions/1.4/Home/bin/java)
$ java -version
java version "1.6.0_17"
Java(TM) SE Runtime Environment (build 1.6.0_17-b04-248-10M3025)
Java HotSpot(TM) 64-Bit Server VM (build 14.3-b01-101, mixed mode)
$