CSCI 6962: Server-side Design and Programming Course Introduction and Overview

Topics Introduction to Client-Server Web Architectures Java Server Faces and Active Server Pages Problems and Topics in Server-side Programming Programming Assignments 2

3 Client-Server Web Architecture Client browser sends request for page to server –May contain form data and other information Server sends response page and sends to client May need to generate response page dynamically –Form parameters –Previous requests (such as items purchased so far) –Information in database Focus of this course

4 Client-Server Web Architecture Client Browser ~john/Syllabus.html Request to for Syllabus.html Server john  public_html port Response containing Syllabus.htm as a long string ( CSCI 6962 Syllabus …) Syllabus.html

5 Dynamic Form Handling Form data appended to request string Generates the request: <FORM NAME="purchaseform" METHOD=GET ACTION= bin/test.pl > bin/test.pl Quantity: /FORM>

6 Form Handling Server must: –Listen on port for requests –Parse request to determine values of parameters –Dynamically generate appropriate response page based on parameter values –Send response page back to client

7 Web Containers Program running continuously on server Runs code to handle requests Built-in methods for parsing requests, generating responses Handles other important functions: –Session tracking –Database access – generation –Security and encryption –…–…

8 Web Containers Client Browser Server Port Web Container Constantly running in background Listen on port Execute code in requested server page Generate corresponding html page cgi-bin response Thank you for your order of widgets!

9 Web Containers Glassfish –Written in Java –Built on Apache Tomcat –NetBeans IDE –Acts as engine for Java servlets, Java Server Pages and Java Server Faces Microsoft Internet Information Server (IIS) –Visual Basic/C# –Acts as engine for Active Server Pages

Server-side Evolution Servlets –Programmatically generating response page Server pages –Inserting dynamically generated code into web page –Goal: separate web design and dynamic code Server faces/Active server pages –Directly linking client-side form elements to server-side objects (JavaBeans) –Goal: separate web page development from underlying business logic 10

Java Servlets 11 Get quantity from request Create output to response Write response page as string to output with quantity inserted

12 Java Server Pages Java code executed inside web page Resulting value inserted into html

Java Server Faces Use managed beans to control information –Data storage between pages –Computation methods (total bill, taxes, etc.) –Validation methods (positive quantity, items available) –Long-term storage (database read/write of orders) 13 JSF web page JSF managed bean Web design team Business logic team

Java Server Faces 14 Bean stores quantity Getters and setters to allow access

Java Server Faces 15 XML tags specific to JSF Input bound to quantity property of bean

Java Server Faces 16 widgetBean quantity: 3 3

17 Active Server Pages Active Server Page approach: Create “form” which is translated to html

18 Active Server Pages Server-side code manipulates “form elements” –Subroutine called when page submitted –Data read from elements (actually request string) –Used to set value of other elements

19 Active Server Pages Resulting form translated to response page

Why Two Platforms Both widely used in practice –Other platforms (Springs, Ruby, etc.) based on JSF model Different approaches but common ideas –Same underlying representation –Same best practices for web site design 20

Other Major Topics Session management Modular web site design Validation and error handling Database manipulation AJAX client-server communication Security 21

22 Session Handling Most web transactions are sessions consisting of series of requests and responses Must associate steps if multiple clients Who submitted this request?

Modular Web Pages Most pages on same site have similar content, layout, etc. Goal: Write once, include in all pages Tools: –Facelets (Java) –Master Pages (ASP) 23

24 Form Validation Detecting user error –Built-in validation tools Correcting user error –Providing information or how to correct error Preventing user error –Field types/values –Error tolerance

25 Database Manipulation Database driver provides access to databases Built-in tools to manipulate/display data –JDBC: classes to query/manipulate database –Java Persistence API beans –ASP Data Source objects web container JPA bean JSF page database database driver JDBCDBMS database server

26 AJAX Asynchronous JavaScript and XML Based on JavaScript running in browser –JavaScript code sends data to server, reads response –Response is simple data instead of entire page –JavaScript code then modifies page without re-rendering it completely Method call Web Page Server Return value JavaScript

Web Site Security SSL/TLS for encryption Certificates for server authentication Secure programming against attacks –SQL injection –Cross-site scripting 27 Request Server Response Client Certificate database database server

Programming Assignments Introductory Assignments –Simple Java Server Faces web site –Simple Active Server Pages web site Web Site Project (four parts) –Modular user interface design –Validation and error handling –Database access –Shopping cart and other support objects 28

Web Site Project “E-Commerce” site of your design You choose platform (JSF or ASP) 29 List of products Individual Product pages with “add” option “Cart” of added products Shipping/ payment/ etc. information \Database of products and orders

30 Background Knowledge Java or C++ (for JSP) –May want to get Java reference –I will cover basics in class Visual Basic or C# (for ASP) –Basics covered in class –If more familiar with C# can get corresponding text Basic html (including forms and tables) Basic SQL