Lập trình web-1

Server-side
Web Programming
Lecture 2:
The Jakarta Tomcat Web Container and the NetBeans IDE
Client-Server Web Architecture
Client
Browser
www.cis.ysu.edu/~john/Syllabus.htm
Request to www.cis.ysu.edu
for Syllabus.htm
Server

john public_html Syllabus.htm
port
Response containing Syllabus.htm as a long string (…)
Client browser sends request for page to server
Server sends response page and sends to client
Form Handling
Server must:
Listen on port for requests
Parse request to determine values of parameters
Generate appropriate response page based on parameter values
Send response page back to client
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
Email generation
Security and encryption
Web Containers
Jakarta Tomcat
Written in Java
NetBeans IDE
Acts as engine for Java Server Pages and servlets
Microsoft IIS
Visual Basic/Visual C++
Active Server Pages
Downloading the Java SDK
Downloading the Java SDK
Downloading the Java SDK
Downloading the Java SDK
Downloading the Java SDK
Installing Tomcat
Detailed Instructions in Chapter 2 (page 31)
Copy JAR files from Tomcat to Java Runtime Environment
Necessary for JSPs and servlets to compile
Installing Tomcat
Tell Tomcat where to look for Java (page 34)
Edit catalina.bat file in bin directory of Tomcat
Testing Tomcat
Start Tomcat
Execute statup.bat in bin directory
Testing Tomcat
This will open Tomcat control window
Testing Tomcat
Tomcat is now listening for requests!
Listening at port 8080 by default
Test: enter http://localhost:8080/ in your browser
Tomcat Structure
Listens on port 8080 for requests
Retrieves page requested
Must be part of its file structure in webapps directory
Example: http://localhost:8080/
Sends request to this machine for index.html file in ROOT subdirectory of webapps
Tomcat Structure
Another example: http://localhost:8080/examples/jsp/simpletag/foo.jsp
Tomcat Structure
Side point:
JSPs/servlets can display messages in Tomcat window (often used for diagnostics)
Tomcat Structure
Meaning of this URL:
http://localhost:8080/examples/jsp/simpletag/foo.jsp
Invoke server listening on port 8080 of this machine
Access this file in this subdirectory of the tomcat/webapps directory
Tomcat Structure
Side note: Usually refer to server on another machine http://www.cis.ysu.edu/examples/jsp/simpletag/foo.jsp




For testing, often run client and server on same machine
Invoke server at this remote URL
Access this file in this subdirectory of the tomcat/webapps directory
Port 8080
http://localhost:8080/...
Browser
Tomcat
response
response
request
request
Tomcat Structure
If requested page is server page/servlet, executes code embedded in page to generate corresponding html page
Final html page sent as response
The NetBeans IDE
Integrated Development Environment for Java Programming
Editing code (with hints)
Compiling code
Running code
Good for JSP/servlet development
Allows easy development of web applications
Automatically interacts with Tomcat
No need to manipulate Tomcat file structure
Adding a Tomcat Server
Tools  Servers

Press
Adding a Tomcat Server
Select Tomcat 6.0
Adding a Tomcat Server
Enter the directory
where you installed
Tomcat

Enter a name and
a password for a
“manager” role
(we will use this
more later)
Adding a Tomcat Server
By default, Tomcat listens at port 8080

Creating a Web Application
In NetBeans: File  New Project
Choose Web and Web Application
Creating a Web Application
Give your project a name (I called this one “WidgetSite”)
Give it a location (I have put it in a directory called 6962)
Make sure it is set as the Main Project

Creating a Web Application
The final page shows information (such as which server this project uses)
You can press “finish” at this point
Creating a Web Application
NetBeans creates an initial web site
Structure shown in the project window
Creates an initial index.jsp page (default home page of the new site)
The index.jsp is initially just a “Hello world” page
Running a Web Application
Running the site opens the index.jsp page
Can choose browser (and should test with all!)
Building a Web Application
Modify and add files to create web site
index.jsp
Prompts user for
number of widgets
reciept.jsp
Displays number of
widgets purchased
Building a Web Application
Adding a JSP
File  New
Choose a JSP
Give it a name
Running the Site
Deploying your Site to Tomcat
Right-click project and choose “Deploy”
This copies all web site files into buildweb subdirectory
Deploying your Site to Tomcat
Copy these files into a subdirectory of webapps in Tomcat
Deploying your Site to Tomcat
Start Tomcat (after closing NetBeans)
Go to http://localhost:8080/WidgetSite in browser