How to install Java SDK (1.6) and Apache Ant (1.7) on CentOS

I had enough with some package managers or alternative ways of installing Java on a server which is running CentOS (RHEL) 4.4 . I think the most straight forward way is the following. I promise by the end of this post you will have Java and Apache Ant running on you server!

SETUP JAVA

Step 1: Download Java SDK for Linux (I have used the .bin file)

Step 2: upload the .bin file to your server – I have picked the following folder /usr/lib/
So it would be /usr/lib/jdk-6u1-linux-i586.bin (this is JDK1.6 update 1 for my case maybe when you read this post is jdk1.7).

Step 3: Unpack – extract the bin file contents of the bin file

    > chmod 777 jdk-6u1-linux-i586.bin
    > ./jdk-6u1-linux-i586.bin

Step 4: Follow the instructions and type yes when prompted to do so! After unpacking you should have the following folder /usr/lib/jdk1.6.0_01/

Step 5: Go to the /etc/alternatives folder and create a sym link to the java executable

    > cd /etc/alternatives
    > ln -s /usr/lib/jdk1.6.0_01/bin/java java

Step 6: Go to the /usr/bin folder and create a sym link pointing to the sym link of alternatives
(there are 2 levels of sym links that may prove to be handy in case we change to a new version after a while)

    > cd /usr/bin/
    > ln -s /etc/alternatives/java /usr/bin/java

Yes this is it you may test if Java( runtime) is there by typing

    > java -version

Java(TM) SE Runtime Environment (build 1.6.0_01-b06)
Java HotSpot(TM) Client VM (build 1.6.0_01-b06, mixed mode, sharing)

SETUP JAVA_HOME

Step 1: Based on the installation above I would like to create another sym link to point on the jdk folder so

    > cd /etc/alternatives
    >ln -s /usr/lib/jdk1.6.0_01/ /etc/alternatives/jdk

So if I do a

    > cd /etc/alternatives/jdk
    >ls

I get the contents of the actuall jdk160 folder

Step 2: Set the JAVA_HOME variable globally!

    > cd /etc/
    > vi ./profile

(hope you know the basics of vi)

Step 2.1 :there add a new line with the following
JAVA_HOME ="/etc/alternatives/jdk"

Step 2.2: and change the existing line
from
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE INPUTRC
to
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE INPUTRC JAVA_HOME

Step 3: you should restart your bash session in order the new variable to be loaded just check

    > echo $JAVA_HOME
    /etc/alternatives/jdk

Done!

SETUP APACHE ANT

Step 1: Go to the /usr/lib/ folder and wget apache ant gz file

    >cd /usr/lib/
    > wget http://apache.forthnet.gr/ant/binaries/apache-ant-1.7.0-bin.tar.gz

Step 2: When it is finished unpack the archive

    >gzip -d apache-ant-1.7.0-bin.tar.gz
    > tar -xvf apache-ant-1.7.0-bin.tar

You should end up with a folder /usr/lib/apache-ant-1.7.0/

Step 3: Lets create some Sym links again for the ant executable

    >ln -s /usr/lib/apache-ant-1.7.0/bin/ant /etc/alternatives/ant

Step 4: :Lets create some Sym links for the ant home directory

    >ln -s /usr/lib/apache-ant-1.7.0/ /etc/alternatives/anthome

Step 5: Lets create a sym link to the /usr/bin folder for ant

    > ln -s /etc/alternatives/ant /usr/bin/ant

Step 6: Add the ANT_HOME variable like we did with java home

    >cd /etc/
    >vi ./profile

Step 6.1 : Add the following line
ANT_HOME="/etc/alternatives/anthome"

Step 6.2 : add ANT_HOME to the export statement
export PATH USER LOGNAME MAIL HOSTNAME HISTSIZE INPUTRC JAVA_HOME ANT_HOME

Restart your terminal session and now if you type:

    >ant -version
    Apache Ant version 1.7.0 compiled on December 13 2006

    >echo $ANT_HOME
    /etc/alternatives/anthome

Done!

Src: http://javapapo.blogspot.com/2007/04/how-to-install-java-sdk-6-and-apache.html