1. Download the latest version of java from java.sun.com


2. Extract the file in your home folder.



3. Run the following commands in terminal

   
   
   

   sudo mkdir -p /usr/lib/java/

   
   
   

   sudo mv jdk1.7.0/ /usr/lib/java/




4. Find the file profile in etc folder of FileSystem




5. Edit in editor and write the line

   
   
   

   export PATH=/usr/lib/java/jdk1.7.0/bin:$PATH




6. save it. You might need to restart your system to make these change.

You can check the current version using the following command javac -version