Web Components Browser Application progra a Web server Users interface to Web Becomes web client to fetch Document representation information from Web server ransfer protocol Displays information for user 工 nside a browser Illustration of a browser Main controller Receives input from user 一m Invokes client and interpreter a Clients One or more built Uses network to fetch items One or more built in Displays items a Browser contains many components Alternative Protocol Example Web Server File transfer service Running program Protocol is FTP Stores set of web documents Example URL Responds to request from browser by ftp: //Etp. cs. purdue. edu/pub/comer/netbook/clientc ding copy of documen Can be used in anchor te2 哈工大计算机学院 李全龙 Network Application Development Server Software Design 7 Web Components „ Browser „ Web server „ Hypermedia links „ Document representation „ Transfer protocol 哈工大计算机学院 李全龙 Network Application Development Server Software Design 8 Browser „ Application program „ User’s interface to Web „ Becomes Web client to fetch information from Web server „ Displays information for user 哈工大计算机学院 李全龙 Network Application Development Server Software Design 9 Inside a Browser „Main controller „ Receives input from user „ Invokes client and interpreter „ Clients „One or more built into browser „ Uses network to fetch items „ Interpreter „One or more built in „ Displays items 哈工大计算机学院 李全龙 Network Application Development Server Software Design 10 Illustration of a Browser „ Browser contains many components 哈工大计算机学院 李全龙 Network Application Development Server Software Design 11 Alternative Protocol Example „ File transfer service „ Protocol is FTP „ Example URL ftp://ftp.cs.purdue.edu/pub/comer/netbook/client.c „ Can be used in anchor tag 哈工大计算机学院 李全龙 Network Application Development Server Software Design 12 Web Server „ Running program „ Stores set of Web documents „ Responds to request from browser by sending copy of document