JDK or Java Development Kit is a combination of software, tools required to compile, debug, and run applets and applications written using Java language.

• To use JSP one needs to install Java SDK also known as JDK which has a Java Compiler.
• To Download Java SDK visit "http://java.sun.com/javase/downloads", choose the platform in which you want to install from windows, solaris, linux and install the JDK.
• Before running the Tomcat Server we need to check whether the Java environment variable is set.
• On a windows system, set the JAVA_HOME variable to the installed directory of JDK, as below.
• And, set the PATH variable to the bin directory of JDK, from the command prompt as below.
• C:\> set JAVA_HOME=C:\ jdk1.6.0_07
• C:\> set PATH=%JAVA_HOME%\bin; %PATH%
• This can be checked by typing the following command in the command prompt.
• C:\>echo %JAVA_HOME%
• C:\> jdk1.6.0_07
• C:\> echo %PATH%
• C:\>Program Files\Java\jdk1.6.0_07
• Path variables can also be set using the following steps.
• Just Right Click "My Computer->Properties->Advanced"
• Click on "Environment Variables" set the new "path", "classpath" variables.