Java language has experienced a huge amount of modifications since JDK 1.0 as well as many inclusions of classes and many packages to the outstanding library. Right from J2SE 1.4, the development of the Java language has been ruled solely by the Java Community Process (JCP), which makes use of Java Specification Requests (JSRs) to suggest and determine inclusions and modifications to the Java platform. The language is mentioned by the Java Language Specification (JLS); alterations to the JLS are controlled under JSR 901.
Furthermore to the language modifications, much more spectacular modifications have been created to the Java Class Library throughout the years, which has developed from a few thousand classes in JDK 1.0 to over three thousand in J2SE 5. Altogether new APIs, such as Swing and Java2D, have been brought about, and many of the master JDK 1.0 classes and methods have been depreciated. Some programs permit transition of Java programs from one edition of the Java platform to a former one (for example Java 5.0 backed to 1.4).
After the Java 7 had been released, Oracle foretold to go back to a 2 year release cycle. Nevertheless, in 2013, Oracle declared that they might postpone Java 8 by a single year, so as to mend the Java security model.
Install Java 8 on ubuntu 13.10 with the use of PPA
Firstly you require to get rid of any subsisting java versions i.e openjdk by using the follwoing command
$sudo apt-get purge openjdk
Now you require to execute the following commands to install java 8
$sudo add-apt-repository ppa:webupd8team/java
$sudo apt-get update
$sudo apt-get install oracle-java8-installer
You can assure the java version by executing the following command
$java -version
If you want to alter among java versions execute the following command from your terminal
$sudo update-java-alternatives -l
