CICS Transaction Gateway V5 The WebSphere ... - IBM Redbooks

The next section of code deals with the results of the ECI request. If there have
been no errors, then we convert the output COMMAREA into String objects,
using both the default encoding and that specified in the form, and pass them to
the JSP. We also convert the original byte data into a String hexadecimal
representation, to help with data conversion debugging, and pass that to the JSP.
If there has been an error, then we set jsp to forward to the name of the JSP that
displays errors (error.jsp). In either case, we pass the ECI return codes and error
strings to the JSP.
The next section of code handles any exceptions that occur while building and
sending the ECI request. To deal with an exception, we build a message
consisting of a timestamp and the String representation of the exception that
occurred. We then set a request attribute containing this String and specify we
want to forward to the JSP that displays exceptions (exception.jsp).
We then close the JavaGateway connection in a finally block, to ensure it is
closed even if an exception occurs during the flow() method.
The final section of code in the processRequest() method forwards to the
appropriate JSP, set in the member variable jsp (Figure B-10).
// route to jsp
ServletContext servletContext = getServletContext();
RequestDispatcher dispatcher =
servletContext.getRequestDispatcher(jsp);
try
{
dispatcher.forward(request, response);
}
catch(ServletException ex)
{
// log exception to servlet log
servletContext.log("Exception routing to jsp: " + ex);
}
Figure B-10 Routing to a JSP
We get the ServletContext object that represents the current request and
response. We then get the RequestDispatcher object for the selected JSP from
the ServletContext. The forward() method is called on the RequestDispatcher,
passing in the HttpRequest and HttpResponse. This causes the request to be
forwarded to the JSP, along with the objects representing the session. The JSP
will then generate the response HTML.
The other method in our servlet is byteArrayToHex(), which takes a byte array
and converts it to a String showing the array data in a hexadecimal form.
Appendix B. Sample applications 347