How to install java in ubuntu??

• First start your terminal ( if not found on desk top try shortcut key ctrl+alt+T)
  
• make sure you are connected to the internet.
• update your Ubuntu by the command : sudo apt-get update
• then install java (jdk and jre) by the command :
  sudo apt-get install openjdk-6-jdk openjdk-6-jre
• To check if java has been installed in your system, type the following command:
  
  javac -version