How to Install Java In Ubuntu

Installing default JRE/JDK

 Step 1:
  
       sudo apt-get update
Step 2:
      sudo apt-get install default-jre  
Step 3:
  sudo apt-get install default-jdk
   
Step 4:

 java -version

Installing OpenJDK 7

 Step 1:

sudo apt-get install openjdk-7-jre

Step 2:

sudo apt-get install openjdk-7-jdk