A new
or existing application can be enabled to use the Web messaging service.
Enabling a Web messaging application consists of creating or modifying
a Web module to add the necessary Web messaging function. Enabling
the Web messaging server side function is a configuration oriented
task. The Web messaging service handles all details of communicating
to Web messaging clients. The application developer and deployer need
to understand the best way to configure the Web messaging service.
When creating a Web messaging enabled application, an application
or Web developer needs to write the client logic to connect to the
Web messaging service to receive messages delivered by the server.
The target client type for the Web messaging service is an Asynchronous
JavaScriptTM and XML (Ajax) client and an application or Web developer
needs Ajax toolkit skills to create the client side logic. Once
a Web messaging enabled application is created, the Web messaging
enabled application is deployed and managed using standard Web
application techniques. For a step by step overview of how to enable
an application for Web messaging usage, refer to the quick start section. Refer to the QuoteStreamer
sample application for a reference Web messaging enabled application.
A JavaTM Platform, Enterprise Edition (Java EE) utility library is provided for you to insert into your Web module. This library is named, webmsg_applib.jar, and must be included in any Web messaging enabled application. This JAR file is typically placed in your Web module's WEB-INF/lib directory for application usage. Included in this utility library is a Web messaging servlet that must be defined and used to create sevlet mappings and an application level publishing library to easily publish to Web messaging clients through the service integration bus.
At least one servlet mapping must be defined in your Web messaging enabled application. Web messaging clients connect to these mappings for Web messaging operations. Included in the Web messaging utility library is an existing servlet with the class name of com.ibm.websphere.webmsg.WebMsgServlet. One or more definitions to this existing servlet should be defined, mappings to these definitions should be created, and a corresponding entry in the Web messaging configuration with the servlet name must be created. Refer to the quick start section to see an overview on step by step enablement. The provided Web messaging servlet works in conjunction with the underlying Web messaging channel framework piece to provide Web messaging communication. Consider the following points when defining new Web messaging servlets and servlet mappings: