java，javac等命令行工具对JAVA_HOME环境变量的值敏感，如果此变量使用1.6指向1.6 JDK.工具/usr/libexec/java_home在这里是您的朋友.正在运行

The java, javac, etc. command line tools are sensitive to the value of the JAVA_HOME environment variable and will use 1.6 if this variable points to a 1.6 JDK. The tool /usr/libexec/java_home is your friend here. Running

/usr/libexec/java_home

将为系统上最新的JDK打印适当的JAVA_HOME值.这将是Java 7，但是您可以使用-v标志来应用约束，例如

will print out the appropriate JAVA_HOME value for the most up to date JDK on your system. This will be Java 7, but you can apply constraints using the -v flag, for example

/usr/libexec/java_home -v '1.6*'

将为系统上***的 1.6 JDK返回JAVA_HOME值.您可以使用此值设置JAVA_HOME:

will return a JAVA_HOME value for the best available 1.6 JDK on your system. You can use this value to set JAVA_HOME:

export JAVA_HOME=`/usr/libexec/java_home -v '1.6*'`

通过将以上行添加到主目录中的.bash_profile文件中，将

一次性地用于特定的终端会话，或者永久地用于所有将来的终端会话.

either as a one-off for a particular Terminal session, or permanently for all future terminal sessions by adding the above line to the .bash_profile file in your home directory.

$ export JAVA_HOME=`/usr/libexec/java_home -v '1.6*'`
$ java -version
java version "1.6.0_37"
Java(TM) SE Runtime Environment (build 1.6.0_37-b06-434-11M3909)
Java HotSpot(TM) 64-Bit Server VM (build 20.12-b01-434, mixed mode)
$ export JAVA_HOME=`/usr/libexec/java_home -v '1.7*'`

$ java -version
java version "1.7.0_09"
Java(TM) SE Runtime Environment (build 1.7.0_09-b05)
Java HotSpot(TM) 64-Bit Server VM (build 23.5-b02, mixed mode)