SOEN 343 Software Design Computer Science and Software Engineering Department Concordia University Fall 2004 Instructor: Patrice Chalin

Agenda – Lecture 10a Review & renew. Controller Patterns Some solutions to exercise set 9. Controller Patterns GRASP EA 11/10/2018 SOEN 343, © P.Chalin,

Do-it-all Servlet Redesign solutions: lect09.ppt SOEN 343, © P.Chalin, 11/10/2018 SOEN 343, © P.Chalin,

Presentation Domain Data Source Controller Patterns Page Controller Template View Presentation Front Controller Transform View Domain Model Transaction Script Domain Data Mapper Active Record Table Module Data Mapper Row Data Gateway Table Data Gateway Data Source Table Data Gateway 11/10/2018 SOEN 343, © P.Chalin,

Page Controller 11/10/2018 SOEN 343, © P.Chalin,

A1 Page Controllers protected void processRequest( HttpServletResponse response) throws ServletException, java.io.IOException // { TaskListHelper helper = new TaskListHelper(); try { ViewTaskListTS.execute(helper); } catch (Exception e) { helper.appendStatus(e.toString()); } if (helper.getTaskList() == null) { request.setAttribute("errorMessage", helper.getStatus()); forward("Error.jsp", request, response); } else { request.setAttribute("helper", helper); forward("TaskManager.jsp", request, response); 11/10/2018 SOEN 343, © P.Chalin,

A1 Page Controllers protected void processRequest(…) throws … { TaskListHelper helper = new TaskListHelper(); try { ViewTaskListTS.execute(helper); } catch (Exception e) { helper.appendStatus(e.toString()); } if (helper.getTaskList() == null) { request.setAttribute("errorMessage", helper.getStatus()); forward("Error.jsp", request, response); } else { request.setAttribute("helper", helper); forward("TaskManager.jsp", request, response); 11/10/2018 SOEN 343, © P.Chalin,

Page Controller vs. Front Controller – Differences in URL 11/10/2018 SOEN 343, © P.Chalin,

Page Controllers for A1 http:/stu.cs/343A1/ViewTaskList http:/stu.cs/343A1/AddTask http:/stu.cs/343A1/RemoveAllTasks … 11/10/2018 SOEN 343, © P.Chalin,

Front Controller for A1 Base URL: http:/stu.cs/343A1/frontController …/frontController ?command=ViewTaskList …/frontController ?command=AddTaskGrade&title=abc&… 11/10/2018 SOEN 343, © P.Chalin,

Front Controller 11/10/2018 SOEN 343, © P.Chalin,

Front Controller 11/10/2018 SOEN 343, © P.Chalin,

Front Controller (Fowler) Command (GoF) Patterns FrontCommand + init ( ) + processRequest ( ) RemoveStudentCommand ViewStudInfoCommand + processRequest ( ) + processRequest ( ) 11/10/2018 SOEN 343, © P.Chalin,

Front Controller: Sequence Diagram 11/10/2018 SOEN 343, © P.Chalin,

Front Controller: ProcessRequest 11/10/2018 SOEN 343, © P.Chalin,

Front Controller (cont’d) 11/10/2018 SOEN 343, © P.Chalin,

Assignment 2: Front Controller Solution 11/10/2018 SOEN 343, © P.Chalin,

Front Controller: Advantages? 11/10/2018 SOEN 343, © P.Chalin,