Change JAVA version in Oracle Linux

In command line:

#java -version

or

#java -showversion

It shows something like:

java version "1.4.2.0"

Java(TM) SE Runtime Environment .....

Obtain rpm. In my example, I got jdk-7u3-linux-x64.rpm

Install it:

#rpm -ivh jdk-7u3-linux-x64.rpm

###############################100%

Find out rpm installation location:

# rpm -qi jdk-1.7*

Name : jdk Relocations: /usr/java

Version : 1.7.0_03 Vendor: Sun Microsystems, Inc.

Release : fcs Build Date: Fri 20 Jan 2012 03:30:26 PM EST

Install Date: Sun 01 Apr 2012 08:23:26 AM EDT Build Host: jdk7-lin-amd64

Group : Development/Tools Source RPM: jdk-1.7.0_03-fcs.src.rpm

Size : 117905566 License: http://java.com/license

Signature : (none)

Packager : Java Software

URL : URL_REF

Summary : Java(TM) Platform Standard Edition Development Kit

Description :

The Java Platform Standard Edition Development Kit (JDK) includes both

the runtime environment (Java virtual machine, the Java platform classes

and supporting files) and development tools (compilers, debuggers,

tool libraries and other tools).

The JDK is a development environment for building applications, applets

and components that can be deployed with the Java Platform Standard

Edition Runtime Environment.

Now, we know that it is in /usr/java/jdk1.7.0_03

Installing alternatives for java:

# /usr/sbin/alternatives --install /usr/bin/java java /usr/java/jdk1.7.0_03/bin/java 2

Configuring java programs (in my case, I enter 2 in selection):

# /usr/sbin/alternatives --config java

There are 2 programs which provide 'java'.

Selection Command

-----------------------------------------------

*+ 1 /usr/lib/jvm/jre-1.4.2-gcj/bin/java

2 /usr/java/jdk1.7.0_03/bin/java

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

Now, I check for my java version:

# java -version

java version "1.7.0_03"

Java(TM) SE Runtime Environment (build 1.7.0_03-b04)

Java HotSpot(TM) 64-Bit Server VM (build 22.1-b02, mixed mode)

Thank you.