The registered request handler is responsible for processing a particular request from a HTML client. The handler may need to be aware of the device type; this is managed by the channel context. The request handler performs the following tasks to integrate with the application:
▪ Establish the session between the client and the server for the specific device \
▪ Execute a generic application operation for the HTML channel
▪ Determine the appropriate presentation handler from the handler registry to render the results back to the client. For information on the handler registry,
HtmlPresentationHandler
The registered presentation handler is responsible for processing the reply to the HTML client. The main API provided by this class is void processReply(ChannelContext, ServerOperation). This starts the process of dynamically creating the HTML and rendering it to the client using the servlet JSP engine.
HtmlRequestData
This class is used by the RequestValidationServices. It encapsulates the objects that are used when processing a request from an HTML client. The objects encapsulated are the operation, the channel context, and the operation completion time.
HtmlConstants
The HtmlConstants class defines all the constants required by the HTML Channel, including the key strings that are used in contexts, hidden fields, and HttpServletRequest attributes. See the Javadoc for this class for information about these constants.
RequestValidationServices
This class provides the implementation of request validation, protecting the user from an unintentional duplicate request or a back click to a page that corresponds to a finished or expired process.
JspContextServices
This interface defines the protocol to be used by the JSP files for interaction with the context involved with the current request, to set hidden fields in the request, to support exception messages, and other related tasks.
DSEJspContextServices
This class implements JspContextServices. It can be instantiated on a JSP with the useBean tag. This class receives the operation context from the request and then extracts information from the context and emits it to the page as hidden fields. It has other methods to support exception messages, URL rewritten links, and to obtain the session and operation Context objects.