Installation of Java Runtime Edition (JRE) 1.7 in Centos 6.2 and Uninstallation of JDK

Uninstallation of JDK (Open Java)
# yum remove java

Installing from rpm package

Go to the Oracel Download page and download the package.

# wget http://download.oracle.com/otn-pub/java/jdk/7u17-b02/jdk-7u17-linux-x64.rpm

Go to the downloaded location

change the package mode to executeable

# chmod 755 jdk-7u17-linux-x64.rpm

Install it

# yum install jdk-7u17-linux-x64.rpm

Now check the version

# java -version

You should get the result like below:

java version "1.7.0_17"
Java(TM) SE Runtime Environment (build 1.7.0_17-b02)
Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)

Setting JAVA_HOME for a single user and all users:

check java by

#which java
/usr/bin/java

we can check whether this java file is located

# ls -al /usr/bin/java
lrwxrwxrwx. 1 root root 26 Mar 24 20:15 /usr/bin/java -> /usr/java/default/bin/java

#cd /usr/java
#ls -al
drwxr-xr-x.  3 root root 4096 Mar 24 20:15 .
drwxr-xr-x. 14 root root 4096 Mar 24 20:15 ..
lrwxrwxrwx.  1 root root   16 Mar 24 20:15 default -> /usr/java/latest
drwxr-xr-x.  8 root root 4096 Mar 24 20:15 jdk1.7.0_17
lrwxrwxrwx.  1 root root   21 Mar 24 20:15 latest -> /usr/java/jdk1.7.0_17

The above shoes that default softlink to /usr/java/latest and latset softlink to /usr/java/jdk1.7.0_17
The genuine directory for java is /usr/java/jdk1.7.0_17

For a single user:

# vi ~/.bash_profile
# export JAVA_HOME=/usr/java/jdk1.7.0_17
# export PATH=$PATH:/usr/java/jdk1.7.0_17/bin

For all users:

# vi /etc/profile
# export JAVA_HOME=/usr/java/jdk1.7.0_17
# export PATH=$PATH:/usr/java/jdk1.7.0_17/bin