COP 3813 Intro to Internet Computing Prof Roy

COP 3813 Intro to Internet Computing Prof. Roy Levow Last Lecture

Other Internet Technologies Extensible Markup Language (XML) u Web Servers u Database Servers u Active Server Pages (ASP) u Common Gateway Interface (CGI) u – Perl, PHP, Python VBScript u Java Technology u – Java, Servlets, Java. Server Pages (JSP)

XML u W 3 C Standard u Language used to define other markup languages – XHTML, Math. ML, Voice. XML, … u Elements describe data – Propertes and Operations u Processing requires and XML parser

XML Markup u Creates a tree-structure for a document u Example: fig. 20. 1

XML DTDs and Schemas u Document Type Definition – Specifies elements for markup of a particular type of document u Example: fig 20. 6 u Schemas – More versatile than DTDs u Example: fig. 20. 7, fig. 20. 8

Web Servers u Internet Information Server (IIS) – Microsoft u Apache – Apache Software Foundation (freeware) u Support access to a subtree of directories on server u Provide server-side services

Database Servers Provide network access to databases u Generally support relational model u Operations using SQL u u u My. SQL (free), MS Access, many other commercial Access through scripting languages on client or on server

ASP. NET u Active Server Pages – Server applications – Microsoft u. NET – Microsoft portable and reliable execution environment u. NET Framework – Manages and executes applications – Provides Framework Calss Library

ASP. NET (cont. ) u Dynamic web content marked up as HTML u. aspx files u Example: fig. 23. 3

Common Gateway Interface (CGI) u Allows web server to execute code on server u Whether web page or program determined by name extension u Browser can include parametes with request for program u Program can be anything executable on the server

CGI (cont. ) u Output of program is written back to web client u Most efficient if program is run within web server u Perl was first language integrated into Apache server – Others followed

Perl u Simple script language u Freely available for many platforms u Extensible through “modules” – CGI for HTML – DBI for database u Example: fig. 25. 15

PHP u Server-side scripting language for creating web pages. u Combines script into HTML page u Example: fig. 26. 1

VBScript u Microsoft script lanuage derived from Visual Basic u Browser support only in IE, so rarely used on client side u Can be used for server-side ASP scripting u Example: fig. 32. 15

Python u Object-oriented scripting language u Used for server-side applicaitons u Free u Good features for web development u Example: fig. 35. 18

Java Servlets u Use Remote Method Invocation (RMI) between Java on client and server u Developed as part of Jakarta Porject – Tomcat for in Apache server

Web Servlets u Usually extend class Http. Servlet u Example requester: fig. 36. 12 u Example servlet: fig. 36. 11

Java. Server Pages u Extend Servlet concept u Support reuse of Java. Bean components u Can insert content directly into web pages u Example: fig 37. 1 – Note update with refresh meta tag u Example: scripting fig 37. 4 with server-side