5.2 Product limitations in Linux
The level of WebSphere in Linux is lagging from the available version in other
platforms (such as Windows NT or AIX). This poses a considerable restriction
to our ability to utilize several of the new key features that really make the
e business development easier, such as the RequestDispatcher class. See
Section 5.2.1, The RequestDispatcher class on page 142 for a more
comprehensive discussion of this class.
In our project, we access the Lotus Domino database using CORBA. Lotus
Domino server can also be accessed by JDBC. However, the Lotus Domino
Driver for JDBC is only available for a limited number of platforms, and Linux
is not among them. See Section 5.2.2, JDBC connections for Domino on
page 143 for a more comprehensive discussion of this feature from Lotus.
5.2.1 The RequestDispatcher class
The basic use of a RequestDispatcher class is to pass on the current request
to another program (servlet or JSP). A Request Dispatcher has two primary
methods for including the response of another program or forwarding the
request of the current program to another.
Including the response from another program requires the use of the
We would use this if we want to call another servlet from our current
servlet, then perform more processing in the current servlet after calling
this other servlet
Forwarding the request to another program requires the use of the forward
We would use this to forward the request on to another servlet, and then
allow this new servlet to return the response back to the client directly.
Unfortunately for us, the RequestDispatcher class is only available in the Java
JSDK 2.1 API for the javax.servlet class (supported and extended in
WebSphere 3.02). In our servlets, to be run under WebSphere 2.03 (which
only supports and extends JSDK 2.0), we were forced to use the deprecated
callPage method found in package com.sun.server.http. This also explains
the use of the HttpServiceResponse and HttpServiceRequest objects in our
Java code in servlet AccessUserstuf.
Linux Web Hosting with WebSphere, DB2, and Domino