Download RPM

jdk-8u5-linux-x64.rpm from http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html

$ wget --no-check-certificate --no-cookies --header 'Cookie: oraclelicense=accept-securebackup-cookie' http://download.oracle.com/otn-pub/java/jdk/8u5-b13/jdk-8u5-linux-x64.rpm
$ sudo rpm -ivh jdk-8u5-linux-x64.rpm

Make JDK 8 the default with ‘alternatives’

$ sudo alternatives --install /usr/bin/java java /usr/java/jdk1.8.0_05/jre/bin/java 20000

$ sudo alternatives --install /usr/bin/jar jar /usr/java/jdk1.8.0_05/bin/jar 20000
$ sudo alternatives --install /usr/bin/javac javac /usr/java/jdk1.8.0_05/bin/javac 20000
$ sudo alternatives --install /usr/bin/javaws javaws /usr/java/jdk1.8.0_05/jre/bin/javaws 20000

$ sudo alternatives --config java

There are 2 programs which provide 'java'.

  Selection    Command
-----------------------------------------------
*+ 1           /usr/lib/jvm/jre-1.7.0-openjdk.x86_64/bin/java
   2           /usr/java/jdk1.8.0_05/jre/bin/java

Enter to keep the current selection[+], or type selection number: 2


$ java -version
java version "1.8.0_05"
Java(TM) SE Runtime Environment (build 1.8.0_05-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.5-b02, mixed mode)