How to install Java in Linux

To install java in Linux(ubuntu) we have to execute below commands
$sudo apt-get update

$sduo apt-get install default-jre
$sudo apt-get install default-jdk
(or)
if you want latest version java
$sudo apt-get install openjdk-7-jre
$sudo apt-get install openjdk-7-jdk

when there are multiple installation of java in linux
$sudo update-alternatives –config java
(or)
$sudo update-alternatives –config javac

Copy the path above any one(For which version of java installation) For setting JAVA_HOME
$sudo nano /etc/environment
JAVA_HOME=”place here java path”

Test: echo $JAVA_HOME