Migrating Web application components from WebSphere Application Server Version 5.x

Why and when to perform this task

Migration of Web applications deployed in WebSphere Application Server Version 5.x is not necessary; version 2.2 and 2.3 of the Java Servlet specification and version 1.2 and 1.4 of the JavaServer Pages (JSP) specification are still supported. However, where there are behavioral differences between the Java 2 Enterprise Edition (J2EE) 1.2 and J2EE 1.3 specifications, bear in mind that J2EE 1.3 specifications are implemented in WebSphere Application Server Version 5 and will override any J2EE 1.2 behaviors.

Servlet migration might be a concern if your application:

implements a WebSphere internal servlet to bypass a WebSphere Application Server Version 4.x single application path restriction.
extends a PageListServlet that relies on configuration information in the servlet configuration XML file.
uses a servlet to generate Hypertext Markup Language (HTML) output.
calls the response.sendRedirect method for a servlet using the encodeRedirectURL function or executing within a non-context root.

JSP migration might be a concern if your application references JSP page implementation classes in unnamed packages, or if you install WebSphere Application Server Version 4.x EAR files (deployed in Version 4.x with the JSP Precompile option), in Version 5. You need to recompile all JSP pages when migrating from WebSphere Application Server Version 5.x to version 6.

Follow these steps if migration issues apply to your Web application:

Step for this task

Use WebSphere Application Server Version 5 package names for any WebSphere Application Server Version 4.x internal servlets, which are implemented in your application.

In WebSphere Application Server Version 4.x, Web modules with a context root setting of / are not supported. Accessing Web modules with this root context results in HTTP 404 - File not Found errrors.

To bypass the errors, and to enable the serving of static files from the root context, WebSphere Application Server Version 4.x users are advised to add the servlet class, com.ibm.servlet.engine.webapp.SimpleFileServlet , to their Web module.

The Version 4.x single path limitation does not exist in Version 5. However, users who choose to use the com.ibm.servlet.engine.webapp.SimpleFileServlet in Version 5 must do one of the following:

Rename com.ibm.servlet.engine.webapp.SimpleFileServlet to com.ibm.ws.webcontainer.servlet.SimpleFileServlet.
Open a Web deployment descriptor editor using an assembly tool and select File serving enabled on the Extensions tab.

Searchable topic ID: tweb_migrate2