How to install Oracle JDK 7 in Ubuntu Server 12.04 via apt-get command line?

# Step 1: Add the repository for JDK 7.
sudo apt-add-repository ppa:webupd8team/java

# Step 2: Update
sudo apt-get update

# Step 3: Install JDK and associated utilities
sudo apt-get install oracle-java7-installer

# Step 4: Set the default java interpreter used by the system.
sudo update-alternatives --config java