超文本协议与万维网.ppt

Fall 2006 gcsu@ Shenzhen University * * Chapter 27 HTTPandWWW 27.1 HTTP 事务Transaction 请求报文Request Message 响应报文Response Message 头部Headers HTTP 通过公认端口 80使用TCP服务. Note: Figure 27.1 HTTP 事务 Figure 27.2 请求 报文 Figure 27.3 请求行 Figure 27.4 URL Figure 27.5 响应报文 Figure 27.6 状态行 Figure 27.7 头部格式 Figure 27.8 头部 Example 1 This example retrieves a document. We use the GET method to retrieve an image with the path /usr/bin/image1. The request line shows the method (GET), the URL, and the HTTP version (1.1). The header has two lines that show that the client can accept images in GIF and JPEG format. The request does not have a body. The response message contains the status line and four lines of header. The header lines define the date, server, MIME version, and length of the document. The body of the document follows the header (see Fig. 27.9, next slide). Figure 27.9 Example 1 Example 2 This example retrieves information about a document. We use the HEAD method to retrieve information about an HTML document (see the next section). The request line shows the method (HEAD), URL, and HTTP version (1.1). The header is one line showing that the client can accept the document in any format (wild card). The request does not have a body. The response message contains the status line and five lines of header. The header lines define the date, server, MIME version, type of document, and length of the document (see Fig. 27.10, next slide). Note that the response message does not contain a body. Figure 27.10 Example 2 HTTP version 1.1 指定默认的连接是持续连接. Note: 27.2 万维网World Wide Web 超文本与超媒体 浏览器的结构 静态文档/HTML 动态文档/CGI 活动文档Active Document/Java Figure 27.11 分布式服务 Figure 27.12 超文本 Figure 27.13 浏览器的结构 Figure 27.14 网页文档的种类 Figure 27.15 Static document Figure 27.16 粗体标签 Figure 27.17 粗体标签的效果 Figure 27.18 起始与结束标签 Table 27.1 常用标签 Skeletal Tags /Hn /TITLE /BODY /HEAD /HTML Ending Tag Defines the title of the document Hn Defines the title of the