How to instal Java in Ubuntu

This is replication of blog http://rootzwiki.com/topic/23008-howto-install-java-7-on-ubuntu-1204/

Here I give some brief note on how to Install Sun (Oracle) Java in Ubuntu and from How to set JAVA_HOME in Ubuntu post you can get to know how to set your JAVA_HOME appropriately.

For Ubuntu 12.04  for Java 7 ...
First in the terminal enter:

sudo add-apt-repository ppa:eugenesan/java
sudo apt-get update

and then install...

sudo apt-get install oracle-java7-installer 

This will give and error and stop...

Don't worry we can make this work :-)

Go to Oracle Java site [http://www.oracle.com/technetwork/java/javase/downloads/jdk-7u3-download-1501626.html] and download Java "jdk-7u3-linux-x64.tar.gz" directly from their site.

Now, move the downloaded file to /var/cache/oracle-java7-installer/

sudo mv Downloads/jdk-7u3-linux-x64.tar.gz /var/cache/oracle-java7-installer/

Then edit the oracle-java7-installer.postinst file:

sudo gedit /var/lib/dpkg/info/oracle-java7-installer.postinst

To edit scroll down and find the following:           

echo "Downloading..."
rm -f $FILENAME
WGETRC=wgetrc wget $PARTNER_URL
|| fp_exit_with_error "download failed"
rm -f wgetrc
echo "Download done."

And put a # in front of the lines between "echo "Downloading..."" and "echo "Download done."" as follows:

echo "Downloading..."
#rm -f $FILENAME 
#WGETRC=wgetrc wget $PARTNER_URL
#|| fp_exit_with_error "download failed"
#rm -f wgetrc 

echo "Download done."

Save the file and from your terminal run:

sudo apt-get install oracle-java7-installer

Now it works :-)

Check it by running:

java -version

For older versions of Ubuntu (11.10 and older)...
First in the terminal enter:

sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner"
sudo apt-get update

and then install...

sudo apt-get install sun-java6-jdk
sudo apt-get install sun-java6-jre

Now, Java is installed and we need to set the JAVA_HOME.
Visit How to set JAVA_HOME in Ubuntu post to get to know how you can appropriately set JAVA_HOME and PATH.