SET JAVA_HOME IN LINUX

Go to Terminal 
 vi  /etc/profile 


insert the java_path profile file

JAVA_HOME=/usr/local/jdk1.6.0_27
PATH=$PATH:$JAVA_HOME/bin
CATALINA_HOME=/usr/local/tomcat-7.0.20

export JAVA_HOME
export PATH
export CATALINA_HOME


Profile File in /etc/profile

[root@monitoring ~]# cat /etc/profile
# /etc/profile

# System wide environment and startup programs, for login setup
# Functions and aliases go in /etc/bashrc

# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.

JAVA_HOME=/usr/local/jdk1.6.0_27
PATH=$PATH:$JAVA_HOME/bin
CATALINA_HOME=/usr/local/tomcat-7.0.20

export JAVA_HOME
export PATH
export CATALINA_HOME