Session 35 - Design Patterns
- 1. Java & JEE Training Session 35 – Design Patterns
- 2. Page 1Classification: Restricted Agenda • Design Patterns • Flow of the Demo App • Value objects • Data Access object • Factory pattern
- 3. Page 2Classification: Restricted What we covered till now in Servlets… • Servlet API – GenericServlet and HttpServlet • Servlet LifeCycle • Servlet Collaboration using response.sendRedirect() • Forwarding and Including using RequestDispatcher • Parameters and Attributes • Session Tracking / Session Management • Validation: Frontend & Backend.
- 4. The flow of the demo web apps
- 5. Page 4Classification: Restricted Flow of the demo app CLIENT SERVER /index.html Sends back index.html (HTML Code downloaded) /Login Login successful HTML + session id /MoreInfo with parameters + Session ID Page with more information /Logout Page with Logout Success Message
- 6. Design Patterns Value Object, DAO, Factory Pattern, Singleton
- 7. Page 6Classification: Restricted Value Object • Used to compound related characteristics to form a meaningful object (i.e. object of value) e.g. To describe currency, “1000” “USD” make sense when compounded together to form an object anotherMethod(amount,currency,field1,field2,field3…) anotherMethod(money) public class Money{ int amount; String currency; }
- 8. Page 7Classification: Restricted Data Access Object Value Object in DAO pattern
- 9. Page 8Classification: Restricted STUDENT DAO EMPLOYEE DAO DEPARTMENTS DAO ConnectionFactory getConnection() SUPPLIER OF DB CONNECTIONS
- 10. Page 9Classification: Restricted Factory pattern
- 11. Page 10Classification: Restricted Design Pattern Exercise • Exercise: Create a class that can be instantiated • Design Pattern • JDBC Best Practices Continued
- 12. Page 11Classification: Restricted Topics to be covered in next session • JSP (Java Server Pages Technology) • JSP vs Servlet • MVC Architecture • Scriplet