快乐编程

1.which java（whereis java）
2.
[shell]
$ ls -l /usr/bin/java
lrwxr-xr-x 1 root wheel 74 Jan 4 20:24 /usr/bin/java -> /System/Library/Frameworks/JavaVM.framework/Versions/Current/Commands/java
[/shell]
3.
[shell]
$ ls -l /System/Library/Frameworks/JavaVM.framework/Versions
total 64
lrwxr-xr-x 1 root wheel 10 5 11 2014 1.4 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 5 11 2014 1.4.2 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 5 11 2014 1.5 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 5 11 2014 1.5.0 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 5 11 2014 1.6 -> CurrentJDK
lrwxr-xr-x 1 root wheel 10 5 11 2014 1.6.0 -> CurrentJDK
drwxr-xr-x 8 root wheel 272 5 12 2014 A
lrwxr-xr-x 1 root wheel 1 5 11 2014 Current -> A
lrwxr-xr-x 1 root wheel 59 5 11 2014 CurrentJDK -> /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents
[/shell]
4.$ /usr/libexec/java_home
5.$ /usr/libexec/java_home -V
6.$ vim ~/.profile
[shell]
JAVA_HOME=`/usr/libexec/java_home`
export JAVA_HOME
[/shell]