Some commands that you need to know during installing Java on Linux environment:

1) Get the installation package from this command:

sudo apt-get install sun-java-6-jdk


2) Check java version

java -version


3) Check location of installed jdk

sudo update-java-alternatives -l


4)Set default java

sudo update -java-alternatives -s java-6-sun


5) Set JAVA_HOME based on location

export JAVA_HOME=/usr/lib/jvm/java-6-sun


6) Set all the environment path in /etc/environment

JAVA_HOME=/usr/lib/jvm/java


7) Set in the /etc/bash.bashrc

JAVA_HOME=/usr/lib/jvm/java-6-sun
export JAVA_HOME
PATH=$PATH:$JAVA_HOME/bin
export PATH


8 ) Check the environment path

env|grep PATH


If possible, requires restart the pc.