jdk
jre
====================================
# ./jre1.6.0_27-for-linux.bin
# ls /usr/java/jre1.6.0_27/
# mv /usr/java/jre1.6.0_27/* /usr/java/
# vi profile27
export JAVA_HOME=/usr/java
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=$JAVA_HOME/lib
====================================
# sh jdk-6u24-dlj-linux-amd64.bin
# mv jdk1.6.0_24/ /usr/jdk
# vi profile24
export JAVA_HOME=/usr/jdk
export PATH=$JAVA_HOME/bin:$PATH
export CLASSPATH=$JAVA_HOME/lib:$JAVA_HOME/jre/lib
# unpack200 lib/tools.pack /lib/tools.jar
# unpack200 jre/lib/rt.pack /jre/lib/rt.jar
=====================================
# which unpack200
/usr/java/bin/unpack200 (很明显这是个递归)
# . profile27
# which java
# . profile 24
# which java