About JSDK
JSDK is the Java Servlet Developers Kit. This is an add on to the regular JDK (Java Developers Kit). The JSDK has the additional files needed in order to compile Java servlets. The latest version of the JSDK is version 2.0. Included in the JSDK is a Java Servlet Runner program. The Servlet Runner is a program that runs on your workstation, and allows you to test servlets you have written without running a web server. Other files included are the several Java Servlet examples. Included are the .java and .class files for testing purposes and to help you understand how the Java code is implemented. Another important file that is included is the jsdk.jar file. This file includes the class information necessary to compile the servlets.
Installing JSDK
Let me preface the JSDK installation procedures by saying that the JSDK is an add on to the JDK. If you are trying to compile servlets using JSDK, you will be missing software. The JDK includes the javac.exe program and other java library and class files that are necessary to compile java code. Before you start to install the JSDK, install the JDK, then begin JSDK install.
Installing the JSDK is a very simple procedure. When you run the .exe that you download from the http://java.sun.com web site, it will create some temporary web files on your hard drive. It will then launch the installation script. You will be asked to specify the directory you wish to have the files copied to. As in the JDK, the recommended directory includes a 'period' in the directory name (ex. C:\JSDK.20). Change this to C:\JSDK20 instead to make it easier when searching for the directory. After the software is installed, you will have a new subdirectory. In order to use both the JDK and JSDK together, the java compiler (javac.exe) needs to know where the class files are located. I found the easiest way to make this work, is to first put the bin directory for the JDK in the path. This will make it easy to find the javac.exe program when compiling code. Second, add the jsdk.jar file to the classpath. This can be done by adding a SET statement to the autoexec.bat file on your workstation (for Windows 95). The SET statement should read SET CLASSPATH = drive:JSDK install path\lib\jsdk.jar (ex. SET CLASSPATH = C:\jsdk20\lib\jsdk.jar). Once this is done, you will have no problem compiling your java servlets.