How to install oracle java 7 in RHEL7 CentOS7

If you have RHEL 7 fresh installed machine, there must be installed open java as the default java installation. If you want to change java environment to oracle java 7, follow below commands,

First check existing java version,

[akila@localhost u01]#  java -version

It will give you the existing java version like below,

java version "1.7.0_51"

OpenJDK Runtime Environment (rhel-2.4.5.5.el7-x86_64 u51-b31)

OpenJDK 64-Bit Server VM (build 24.51-b03, mixed mode)

To install oracle jdk, first you have to download it from oracle site,

http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads-1880260.html or download it using wget command.

Locate the downloaded file in a specific location, let’s name it as <location>.

Extract downloaded tar file using tar command,

[akila@localhost u01]# tar xzf jdk-7u60-linux-x64.ta

Now install java using alternatives command,

[akila@localhost u01]# alternatives --install /usr/bin/java java  <location>/jdk1.7.0_60/bin/java 2

 [akila@localhost u01]# alternatives --config java

Now you can check java version changed to oracle java 7,

[akila@localhost u01]#  java -version

java version "1.7.0_60"

Java(TM) SE Runtime Environment (build 1.7.0_60-b19)

Java HotSpot(TM) 64-Bit Server VM (build 24.60-b09, mixed mode)

Now you have to set JAVA_HOME and add it to PATH,

[akila@localhost u01]#  export JAVA_HOME="<location>/jdk1.7.0_60"

[akila@localhost u01]# JRE_HOME="<location>/jdk1.7.0_60/jre"

[akila@localhost u01]# export PATH=$PATH: JAVA_HOME/bin: JAVA_HOME/jre/bin

Above commands are only for temporarily. To make changes permanently, you have to update .bash_profile

By default .bash_profile file looks like below,

# .bash_profile

# Get the aliases and functions

if [ -f ~/.bashrc ]; then

        . ~/.bashrc

fi

# User specific environment and startup programs

PATH=$PATH:$HOME/bin

export PATH

Edit the file like below,

# .bash_profile

# Get the aliases and functions

if [ -f ~/.bashrc ]; then

        . ~/.bashrc

fi

# User specific environment and startup programs

JAVA_HOME="/<location>/jdk1.7.0_60"

JRE_HOME="/<location>/jdk1.7.0_60/jre"

export JAVA_HOME

export JRE_HOME

PATH=$PATH:$HOME/bin:/ <location>/jdk1.7.0_60/bin:/ <location>/jdk1.7.0_60/jre/bin

export PATH

Now you have successfully installed java 7 in your RHEL/CentOS 7 machine