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COP 3813
Intro to Internet
Computing
Prof. Roy Levow
Last Lecture
Other Internet Technologies
Extensible Markup Language (XML)
 Web Servers
 Database Servers
 Active Server Pages (ASP)
 Common Gateway Interface (CGI)

– Perl, PHP, Python
VBScript
 Java Technology

– Java, Servlets, JavaServer Pages (JSP)
XML
 W3C
Standard
 Language used to define other
markup languages
– XHTML, MathML, VoiceXML, …
 Elements
describe data
– Propertes and Operations
 Processing
requires and XML parser
XML Markup
 Creates
a tree-structure for a
document
 Example: fig. 20.1
XML DTDs and Schemas
 Document
Type Definition
– Specifies elements for markup of a
particular type of document
 Example:
fig 20.6
 Schemas
– More versatile than DTDs
 Example:
fig. 20.7, fig. 20.8
Web Servers
 Internet
Information Server (IIS)
– Microsoft
 Apache
– Apache Software Foundation (freeware)
 Support
access to a subtree of
directories on server
 Provide server-side services
Database Servers
Provide network access to databases
 Generally support relational model
 Operations using SQL



MySQL (free), MS Access, many other
commercial
Access through scripting languages on
client or on server
ASP.NET
 Active
Server Pages
– Server applications
– Microsoft
 .NET
– Microsoft portable and reliable execution
environment
 .NET
Framework
– Manages and executes applications
– Provides Framework Calss Library
ASP.NET (cont.)
 Dynamic
web content marked up as
HTML
 .aspx files
 Example: fig. 23.3
Common Gateway Interface (CGI)
 Allows
web server to execute code
on server
 Whether web page or program
determined by name extension
 Browser can include parametes with
request for program
 Program can be anything executable
on the server
CGI (cont.)
 Output
of program is written back to
web client
 Most efficient if program is run within
web server
 Perl was first language integrated
into Apache server
– Others followed
Perl
 Simple
script language
 Freely available for many platforms
 Extensible through “modules”
– CGI for HTML
– DBI for database
 Example:
fig. 25.15
PHP
 Server-side
scripting language for
creating web pages.
 Combines script into HTML page
 Example: fig. 26.1
VBScript
 Microsoft
script lanuage derived from
Visual Basic
 Browser support only in IE, so rarely
used on client side
 Can be used for server-side ASP
scripting
 Example: fig. 32.15
Python
 Object-oriented
scripting language
 Used for server-side applicaitons
 Free
 Good features for web development
 Example: fig. 35.18
Java Servlets
 Use
Remote Method Invocation (RMI)
between Java on client and server
 Developed as part of Jakarta Porject
– Tomcat for in Apache server
Web Servlets
 Usually
extend class HttpServlet
 Example requester: fig. 36.12
 Example servlet: fig. 36.11
JavaServer Pages
 Extend
Servlet concept
 Support reuse of JavaBean
components
 Can insert content directly into web
pages
 Example: fig 37.1
– Note update with refresh meta tag
 Example:
scripting
fig 37.4 with server-side