How to install JDK (Java Development Kit) on Linux

This tutorial will guide you on how to install JDK (Java Development Kit) on
Linux. Since I use Centos 5.4 x86_64 in everyday life, this guide is showing you
how to install JDK in Centos 5.4 64bit. It must work in any other Linux distro
such as Slackware, Fedora, Ubuntu et cetera.
If you install a Linux OS, the
developers usually already included a JVM to the system to run some programs
that need Java. Mostly they included OpenJDK for the JVM.

But I don’t like to use OpenJDK because some
Java platform like JavaFX will not run using OpenJDK.

UPDATE! Java SE 6 (JDK 1.6) Update 24 (file name:
jdk-6u24-linux-i586.bin) is now available. You can download the file
from Java SE Downloads page. Java SE 7 (JDK 1.7) Binary
Snapshot build b132 also has been released. If you want to download and install
the Java SE 7, you can get the file fromJava SE 7 download page with the file name
jdk-7-ea-bin-b132-linux-i586-03_mar_2011.bin. This tutorial should be applicable
for those version.

1. Download the JDK

The JDK can be downloaded from its official
website. At the time this tutorial was written, the JDK version is JDK 6
Update 17. Click the Download button then you will be forwarded to Java SE
Download page. You can select the Java platform to suit your system.

Since I use x86_64 of Linux, I choose ‘Linux x64′ for the platform. Then
click ‘Continue’ button. You can skip for the ‘Log in for Downloads’ optional
window. Then select from the available files.

Choose not the ‘rpm’ file because we will install the JDK in a folder as we
want to.

2. After the download is complete, unpack the file by executing
it.

First you have to make it executable.

[[email protected] Downloads]$ chmod +x jdk-6u17-linux-x64.bin

[[email protected] Downloads]$ ./jdk-6u17-linux-x64.bin

inflating: jdk1.6.0_17/README.html

   creating: jdk1.6.0_17/include/

  inflating: jdk1.6.0_17/include/jni.h

   creating: jdk1.6.0_17/include/linux/

  inflating: jdk1.6.0_17/include/linux/jawt_md.h

  inflating: jdk1.6.0_17/include/linux/jni_md.h

  inflating: jdk1.6.0_17/include/jvmti.h

  inflating: jdk1.6.0_17/include/jawt.h

  inflating: jdk1.6.0_17/include/jdwpTransport.h

  inflating: jdk1.6.0_17/include/classfile_constants.h

  inflating: jdk1.6.0_17/COPYRIGHT

Creating jdk1.6.0_17/jre/lib/rt.jar

Creating jdk1.6.0_17/jre/lib/jsse.jar

Creating jdk1.6.0_17/jre/lib/charsets.jar

Creating jdk1.6.0_17/lib/tools.jar

Creating jdk1.6.0_17/jre/lib/ext/localedata.jar

Creating jdk1.6.0_17/jre/lib/plugin.jar

Creating jdk1.6.0_17/jre/lib/javaws.jar

Creating jdk1.6.0_17/jre/lib/deploy.jar
Java(TM) SE Development Kit 6 successfully installed.
Product Registration is FREE and includes many benefits:

* Notification of new versions, patches, and updates

* Special offers on Sun products, services and training

* Access to early releases and documentation
Product and system data will be collected. If your configuration

supports a browser, the Sun Product Registration form for

the JDK will be presented. If you do not register, none of

this information will be saved. You may also register your

JDK later by opening the register.html file (located in

the JDK installation directory) in a browser.
For more information on what data Registration collects and

how it is managed and used, see:
http://java.sun.com/javase/registration/JDKRegistrationPrivacy.html
Press Enter to continue.....
Done.

A folder ‘jdk1.6.0_17′ will be created.

3. Move the ‘jdk1.6.0_17′ folder to a safe place

We will move this folder to a place as you want to. You can move it to /opt
folder, leave it in this directory or to anywhere in the system. I prefer to
move this folder to /usr/local. So move it there.

[[email protected] Downloads]$ sudo mv jdk1.6.0_17 /usr/local/

Here in the /usr/local/ directory, we will create a symbolic link to
jdk1.6.0_17 named as ‘java’

[[email protected] Downloads]$ cd /usr/local/

[[email protected] local]$ sudo ln -s jdk1.6.0_17 java

Now the JDK is installed in /usr/local/jdk1.6.0_17 and linked to
/usr/local/java.
We need to add /usr/local/java/bin folder to the system
PATH. If it is only for your account, add it in .bash_profile file in you home
directory. In Slackware, it should be in .profile file. To make it system wide
environment, add it in the /etc/profile.

Edit a line in .bash_profile to be similar like below:

PATH=$PATH:$HOME/bin:/usr/local/java/bin

This way the PATH will be automatically set at boot time.

You can also set the PATH immediately by using a command below:

$ export PATH=$PATH:/usr/local/java/bin

Now you can call java directly in your shell:

$ java -version

java version "1.6.0_17"

Java(TM) SE Runtime Environment (build 1.6.0_17-b04)

Java HotSpot(TM) 64-Bit Server VM (build 14.3-b01, mixed mode)

4. Upgrade to the latest version

If there is a new JDK version released by Sun/Oracle and you want to upgrade
to the latest version, you can simply follow the steps above. Except for the
third step, after moving the new JDK version to /usr/local/ folder, you need to
remove the existing ‘java’ folder in the /usr/local/ directory and re-create the
symbolic link again.

For example, today on May 18th, 2010, I checked to the java.sun.com website
that the current latest version of the JDK is JDK 6 Update 20. So after
following step 1 and 2, we remove the ‘java’ folder and re-create the symbolic
link again to the ‘java’ folder.

$ sudo rm -rf java

$ sudo ln -s jdk1.6.0_20 java

To make sure it has been successfully upgraded, you can check the current
java version.

$ java -version

java version "1.6.0_20"

Java(TM) SE Runtime Environment (build 1.6.0_20-b02)

Java HotSpot(TM) Server VM (build 16.3-b01, mixed mode)