WebBasedInformationArchitectures.doc

Web Based Information Architectures 复习要点 掌握WWW 的基本概念，包括web,html/sgml,URI,tcp/ip,http,DNS Web：一种信息资源的网络，依靠三种机制使得资源能够对最广泛的潜在读者可用。 1、用于在Web上定位资源的统一命名机制，例如URIs； 2、用于访问Web上命名资源协议，例如HTTP； 3、用于在资源间轻松导航的超文本，例如HTML； Web VS Internet： Internet是一个更通用的词汇，包括底层网络的物理层方面，以及诸如Email、FTP、HTTP等； Web则和Internet上存储的信息相关联，指的是一种更宽泛的网络类别，比如英语文学Web。 Web的核心组成： 1、资源：具体或抽象实体的概念映射，短期内不会变化 2、资源定位符（超链接）：字符串，表示通用地址，可以包含访问需要定位资源的一些指示信息。 3、传输协议：用于规范浏览器（Web用户代理）和服务器间通讯的约定。 Standard Generalized Markup Language (SGML) An international standard (ISO 8879:1986) defines how descriptive markup should be embedded in a document SGML documents have three parts: 声明Declaration: specifies which characters and delimiters may appear in the application 文档类型定义DTD（ document type definition）/ style sheet: defines the syntax of markup constructs 文档实例Document instance: actual text (with the tag) of the documents Hypertext Markup Language (HTML) The Web depends on Web page authors and vendors sharing the same conventions for HTML. This has motivated joint work on specifications for HTML. HTML gives authors the means to: 发布在线信息Publish online documents with headings, text, tables, lists, photos, etc Include spread-sheets, video clips, sound clips, and other applications directly in their documents 通过超文本链接连接信息Link information via hypertext links, at the click of a button 设计表单，用于和远程服务之间处理事务Design forms for conducting transactions with remote services, for use in searching for information, making reservations, ordering products, etc URI: Uniform Resource Identifiers Every resource available on the Web has an address that may be encoded by a URI URIs typically consist of three pieces: The naming scheme of the mechanism used to access the resource. (HTTP, FTP) The name of the machine hosting the resource The name of the resource itself, given as a path Protocols Describe how messages are encoded and exchanged ISO抯 Design PrinciplesI A layer should be created where a different level of abstraction is needed Each l