jdk6

$ sudo apt-get install python-software-properties (add-apt-repository 명령어가 없을 시)
$ sudo add-apt-repository ppa:sun-java-community-team/sun-java6
$ sudo apt-get update
$ sudo apt-get install sun-java6-jdk

jdk7

$ sudo apt-get install python-software-properties (add-apt-repository 명령어가 없을 시)
$ sudo add-apt-repository ppa:webupd8team/java
$ sudo apt-get update
$ sudo apt-get install oracle-jdk7-installer