Example 7.16 Command and Controller Strategy Sample Code

/** This processRequest method is invoked from both 
  * the servlet doGet and doPost methods **/
protected void processRequest(HttpServletRequest 
  request, HttpServletResponse response)
  throws ServletException, java.io.IOException {

  String resultPage;
  try {
    RequestHelper helper = new RequestHelper(request);

    /** the getCommand() method internally uses a 
     factory to retrieve command objects as follows:
     Command command = CommandFactory.create(
        request.getParameter(ÒopÓ));
    **/
     Command command =  helper.getCommand();
 
    // delegate request to a command object helper
    resultPage = command.execute(request, response);
  }
  catch (Exception e) {
    LogManager.logMessage("EmployeeController",
      e.getMessage() );
    resultPage = ApplicationResources.getInstance().
                      getErrorPage(e);
  }

  dispatch(request, response, resultPage);
}