A brief discussion on how to modify/set the environment variable JAVA_HOME under Linux

JAVA_HOME=/usr/local/java/jdk1.7.0_25
JRE_HOME=$JAVA_HOME/jre
CLASSPATH=$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar
PATH=$JAVA_HOME/bin:$PATH
export PATH JAVA_HOME JRE_HOME CLASSPATH
or export JAVA_HOME = /home/myuser/jdk1.7.0_03
export PATH = $JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

#oracle related variables export ORACLE_SID=orcl
export ORACLE_BASE=/u01/app/oracle
export ORACLE_HOME=$ORACLE_BASE/product/11.2.0/dbhome_1
export LD_LIBRARY_PATH=$ORACLE_HOME/lib:/usr/lib
export PATH=/u01/app/oracle/product/11.2.0/dbhome_1/bin:/bin:/usr/bin:/usr/sbin:/usr
/local/bin:/usr/X11R6/bin
export PATH=$ORACLE_HOME/bin:$PATH:/sbin/

//Modify the .bash_profile file in the user directory $ vi /home/myuser/.bash_profile
//Add the following content at the end of the file export JAVA_HOME = /home/myuser/jdk1.7.0_03
export PATH = $JAVA_HOME/bin:$PATH
export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar

$ export JAVA_HOME = /home/myuser/jdk1.7.0_03
$ export PATH = $JAVA_HOME/bin:$PATH
$ export CLASSPATH=.:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib/tools.jar