How to install JDK on your PC

First of all we need to have JDK(Java Development Kit) installed on the PC. Use this Link and download JDK

http://www.oracle.com/technetwork/java/javase/downloads/index.html.

You will see jdk 6 update 1 window as shown below.

Now a "License Agreement" window opens. Just read the agreement and click "Accept" button to accept and go further.

Now a "Custom Setup" window  opens. 

 Click on "Change" button to choose the installation directory. Here it is "C:\Program Files\ Java\jdk1.6.0_01". Now click on "OK" button.

Clicking the "OK" button starts the installation. It is shown in the following figure.

Next window asks to install Runtime Environment

Click the "Change" button to choose the installation directory of Runtime Environment. I prefer not to change it. So click "OK" button.

Click "OK"  button starts the installation.

Now "Complete" window appears indicating that installation of jdk 1.6 has completed successfully. Click "Finish" button to exit from  the installation process.

The above installation will create two folders "jdk1.6.0_01" and "jre1.6.0_01" in "C:\ Program Files\ java" folder.

To make available Java Compiler and Runtime Environment for compiling and running java programs , I set the system environment variables. 

First of all select "My Computer" icon and right click the mouse button. Now click on "system Properties" option. It provides the "System Properties" window , click the 'Advanced' tab. Then Click the "Environment Variables" button. It provides "Environment Variables" window. Now select the pathin System variables and click 'Edit' button. The"Edit System Variable" window will open. Add "c:\Program Files\Java\jdk1.6.0_01\bin" to 'variable value' and click 'Ok', 'Ok' and 'Ok' buttons. 

Now set the JAVA_HOME variable and set its value to " C:\Program Files\Java\jdk1.6.0_01 ".If this variable has not been declared earlier then create a new system variable by clicking on "New" button and give variable name as "JAVA_HOME" and variable value as " C:\Program Files\Java\jdk1.6.0_01 ".Now click "OK". This variable is used by other applications to find  jdk  installation directory. For example, Tomcat server needs "JAVA_HOME" variable to find the installation directory of jdk.

 Now this is the final step to check that you have installed jdk successfully and it is working fine. Just go to the command prompt and type javac and hit enter key you will get the screen as shown below 

Now you can create, compile and run JAVA programs.

-Tharindu Dilshan-