1. J2EE Lecture 1:Servlet and JSP
Dr. Ming Qiu
Xiamen University
Software School

2. 1. Preliminary Topics What do Web Server and Client do?
HTML and HTTP
GET and POST
URL
What will Web Server not do ?

3. 1.1 What do Web Server and Client do?
Head First to Servlets and JSP, Chap 01
1.1 What do Web Server and Client do?

4. 1.1.1 HTML and HTTP HTML- HyperText Markup Language
Head First to Servlets and JSP, Chap 01
1.1.1 HTML and HTTP
HTML- HyperText Markup Language
Web Server often send the browser a set of instructions written in HTML.
Tells the browser how to present the content to the user
HTTP – HyperText Transport Protocol
Allows for simple request and response conversation.
The client sends an HTTP request.
The Server answers with an HTTP response.

5. Head First to Servlets and JSP, Chap 01
1.1.1 HTML and HTTP

6. Head First to Servlets and JSP, Chap 01
1.1.2 GET and POST

7. 1.1.3 Uniform Resource Locators
Head First to Servlets and JSP, Chap 01
1.1.3 Uniform Resource Locators

8. Head First to Servlets and JSP, Chap 01
Type a URL
The browser create an HTTP GET request
The HTTP GET is sent to the server
And generates an HTTP response
The server finds the page
The browser rends HTML
The response is sent to the browser

9. 1.2 What will Web Server alone not do?
Head First to Servlets and JSP, Chap 01
1.2 What will Web Server alone not do?
Dynamic Content
Saving the Data on the Server

10. 2. Servlets
Introduction
Interface Servlet and HttpServlet

11. 2.1Introduction Servlets and Java Server Pages (JSP)
Java How to Program, Fifth Edition, Chap 24
2.1Introduction
Servlets and Java Server Pages (JSP)
Request-response model
Packages javax.servlet
javax.servlet.http
javax.servlet.jsp
javax.servlet.tagext
Form the Web tier of J2EE

12. 2.1Introduction Servlets under control of a container
Java How to Program, Fifth Edition, Chap 24
2.1Introduction
Servlets under control of a container

13. 2.1 Introduction Servlet Request/response mechanism
Head First to Servlets and JSP, Chap 02
2.1 Introduction
Servlet Request/response mechanism

14. 2.1 Introduction What does the container do? Communications support
Head First to Servlets and JSP, Chap 02
2.1 Introduction
What does the container do?
Communications support
Lifecycle Management
Multithread Support
Declarative security
JSP Support

15. 2.1 Introduction How the Container handles a request
Head First to Servlets and JSP, Chap 02
2.1 Introduction
How the Container handles a request

16. Head First to Servlets and JSP, Chap 02
2.1 Introduction

17. Head First to Servlets and JSP, Chap 02
2.1 Introduction

18. Java How to Program, Fifth Edition, Chap 24

19. Java How to Program, Fifth Edition, Chap 24
2.1 Introduction

20. Java How to Program, Fifth Edition, Chap 24
2.1 Introduction

21. Java How to Program, Fifth Edition, Chap 24
2.1 Introduction

22. 2.2 Interface Servlet and HttpServlet
Java How to Program, Fifth Edition, Chap 24
2.2 Interface Servlet and HttpServlet
Interface Servlet
All servlets must implement this interface
All methods of interface Servlet are invoked by servlet container
GenericServlet and HttpServlet

23. 2.2 Interface Servlet and HttpServlet
Java How to Program, Fifth Edition, Chap 24
2.2 Interface Servlet and HttpServlet
Overrides method service
Two most common HTTP request types
get requests
post requests
Method doGet responds to get requests
Method doPost responds to post requests
HttpServletRequest and HttpServletResponse objects

24. 2.2 Interface Servlet and HttpServlet
Java How to Program, Fifth Edition, Chap 24
2.2 Interface Servlet and HttpServlet
HttpServletRequest Interface

25. 2.2 Interface Servlet and HttpServlet
Java How to Program, Fifth Edition, Chap 24
2.2 Interface Servlet and HttpServlet
HttpServletResponse Interface

26. Handling HTTP get Requests Containing Data
Java How to Program, Fifth Edition, Chap 24
Handling HTTP get Requests Containing Data

27. 2.2 Interface Servlet and HttpServlet
Java How to Program, Fifth Edition, Chap 24
2.2 Interface Servlet and HttpServlet

28. 2.2 Interface Servlet and HttpServlet
Java How to Program, Fifth Edition, Chap 24
2.2 Interface Servlet and HttpServlet

29. Handling HTTP post Requests Containing Data
Java How to Program, Fifth Edition, Chap 24
Handling HTTP post Requests Containing Data

30. 2.2 Interface Servlet and HttpServlet
Java How to Program, Fifth Edition, Chap 24
2.2 Interface Servlet and HttpServlet

31. 2.2 Interface Servlet and HttpServlet
Java How to Program, Fifth Edition, Chap 24
2.2 Interface Servlet and HttpServlet

32. 3. JSP JavaServer Pages Reuse existing Java components
Java How to Program, Fifth Edition, Chap 25
3. JSP
JavaServer Pages
Extension of Servlet technology
Reuse existing Java components
Without programming Java
Create custom tags
Encapsulate complex functionality
Classes and interfaces specific to JSP
Package javax.servlet.jsp
Package javax.servlet.jsp.tagext

33. Java How to Program, Fifth Edition, Chap 25
3. JSP

34. Java How to Program, Fifth Edition, Chap 25
3. JSP

35. 3. JSP In the end, JSP is just a servlet
Head First to Servlets and JSP, Chap 07
3. JSP
In the end, JSP is just a servlet

36. 3 JSP JSPs Servlets Used when content is mostly fixed-template data
Java How to Program, Fifth Edition, Chap 25
3 JSP
JSPs
Used when content is mostly fixed-template data
Small amounts of content generated dynamically
Servlets
Used when small amount of content is fixed-template data
Most content generated dynamically

37. 3. JSP Custom Tag Library JSP’s tag extension mechanism
Java How to Program, Fifth Edition, Chap 25
3. JSP
Custom Tag Library
JSP’s tag extension mechanism
Enables programmers to define new tags
Tags encapsulate complex functionality, written in java code
Keep java code out of the pages.