网上好多方法，验证了很多，就这个可用！！！！
Install oracle java 6 in ubuntu 13.04/12.10/12.04
Open the terminal and run the following commands
sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java6-installer
Install oracle java 7 in ubuntu 13.04/12.10/12.04
Open the terminal and run the following commands
sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update
sudo apt-get install oracle-java7-installer