Pervasive computing

The Transaction server run time supports pervasive computing (PvC) through an adapter framework, which includes a generic abstract Java class called HttpPVCAdapterImpl. You can extend this abstract class to create a specific PvC adapter, such as an iMode adapter which supports NTT DoCoMo's iMode mobile Internet access.

Use the PvC adapter to transfer shopping and ordering information conveniently between customer mobile devices, such as personal digital assistants (PDAs) or a cellular phone. This way, customers are not restricted to using a computer and browser to shop at your online store. The PvC adapter preprocesses requests sent from a source device, passes the request to the HCL Commerce Web controller, and transforms the message format to one that the HCL Commerce system can understand so that the appropriate controller command is invoked. Each adapter is device specific and can instruct the Web controller to process requests for its own device type. For example, a PvC adapter can instruct the Web controller to ignore secure protocol (HTTPS) checking in a request.

To support other devices, you can write additional adapters, using the supplied adapter as a base. If you add or change adapters, ensure that you implement the appropriate Java classes and interfaces (the adapter, session context, and controller request object interfaces) to comply with the HCL Commerce adapter framework.

The adapter framework allows you to implement pervasive computing support for your store by handling the display format and session management. Many pervasive computing devices are compact and have small display areas and varying resolutions. For example, a cellular phone screen is small and may be monochrome. A computer monitor, however, is several times larger and usually has color. In HCL Commerce, a controller command provides the capability to format the display based on various device types, by specifying a view name in the Struts configuration file. The view name is returned from the controller command on completion. A single view name can be associated with different JSP files for difference device types; each device type is marked with a unique device identifier in the Struts configuration file. For example, for a PDA, the information on screen may be displayed in monochrome and for a browser, the same information is displayed in color. The Web controller retrieves the appropriate JSP file from the Struts configuration file, based on the device identifier specified in the table.

Each pervasive computing device has its unique way of maintaining a session of transactions. Unlike a browser, where a cookie is used to store session information, a wireless device session is typically maintained by adding an extra parameter to the HTTP Request Header or by appending a unique identifier to the inbound URL. The HCL Commerce adapter framework allows device specific adapters, including session management, to be written for the appropriate protocol.