Architecture of the Web Client

The IBM MQSeries Workflow Web Client uses Java servlet technology to deliver HTML pages to the Web browser. The HTML pages are generated from information retrieved from the MQSeries Workflow system. The following figure illustrates how the different components work together.

Web Client in local configuration

MQSeries Workflow offers a set of C++ APIs that allow access to the Workflow system. The MQSeries Workflow Java APIs are based on the C++ APIs.

The figure shows the Java APIs in a local configuration with the MQSeries Workflow Client installed on the same machine as the Web server. The major advantage of implementing this scenario is that you eliminate an additional network request by calling the C++ APIs directly from the Java APIs.

However, the Java APIs can also be set up up for a remote configuration. This is needed if the platform on which the Web server runs is not supported by a native MQSeries Workflow Client (for example, Linux). For such a configuration, the Java APIs are connected to a Java Agent through IIOP (CORBA).

A Web server that can run Java servlets is needed to create the HTML pages that are displayed in the Web browser. There are a number of Web servers that can run Java servlets out of the box. Other Web servers require a plug-in to be able to run Java servlets. A plug-in that is available for a variety of Web servers can be found on the IBM Web page WebSphere Application Server.

The Web server is then running a set of Java classes that make up the HTTP interface to IBM MQSeries Workflow. These classes convert the information available through the Java APIs into HTML pages and send the pages to the Web browser. After the information has been retrieved from the Workflow system, a Viewer class is called that converts the data into an HTML page. This Viewer class can be customized and it can use JSPs to create the HTML pages.

If your environment does not yet support JSPs, the Web Client's servlet can work with proprietary HTML template files that are stored on the Web server. However, this approach is not as flexible as JSPs.


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