第一部分　HTTP：Web 的基础
第1 章　HTTP 概述 ............................................................................................................................3
1.1　HTTP——因特网的多媒体信使 ...............................................................................................4
1.2　Web 客户端和服务器 .................................................................................................................4
1.3　资源 ............................................................................................................................................5
1.3.1　媒体类型 ........................................................................................................................6
1.3.2　URI.................................................................................................................................7
1.3.3　URL ...............................................................................................................................7
1.3.4　URN ...............................................................................................................................8
1.4　事务 ............................................................................................................................................9
1.4.1　方法 ...............................................................................................................................9
1.4.2　状态码 ..........................................................................................................................10
1.4.3　Web 页面中可以包含多个对象 ..................................................................................10
1.5　报文 ..........................................................................................................................................11
1.6　连接 ..........................................................................................................................................13
1.6.1　TCP/IP ..........................................................................................................................13
1.6.2　连接、IP 地址及端口号 ..............................................................................................14
1.6.3　使用Telnet 实例 ..........................................................................................................16
1.7　协议版本 ..................................................................................................................................18
1.8　Web 的结构组件 .......................................................................................................................19
1.8.1　代理 ..............................................................................................................................19
1.8.2　缓存 ..............................................................................................................................20
1.8.3　网关 ..............................................................................................................................20
1.8.4　隧道 ..............................................................................................................................21
1.8.5　Agent 代理 ....................................................................................................................21
1.9　起始部分的结束语 ...................................................................................................................22
1.10　更多信息 ................................................................................................................................22
1.10.1　HTTP 协议信息 ........................................................................................................22
1.10.2　历史透视 ...................................................................................................................23
1.10.3　其他万维网信息 .......................................................................................................23
第2 章　URL 与资源 ........................................................................................................................25
2.1　浏览因特网资源 .......................................................................................................................26
2.2　URL 的语法 ..............................................................................................................................28
2.2.1　方案——使用什么协议 ..............................................................................................29
2.2.2　主机与端口 ..................................................................................................................30
2.2.3　用户名和密码 ..............................................................................................................30
2.2.4　路径 ..............................................................................................................................31
2.2.5　参数 ..............................................................................................................................31
2.2.6　查询字符串 ..................................................................................................................32
2.2.7　片段 ..............................................................................................................................33
2.3　URL 快捷方式 ..........................................................................................................................34
2.3.1　相对URL .....................................................................................................................34
2.3.2　自动扩展URL .............................................................................................................37
2.4　各种令人头疼的字符 ...............................................................................................................38
2.4.1　URL 字符集 .................................................................................................................38
2.4.2　编码机制 ......................................................................................................................38
2.4.3　字符限制 ......................................................................................................................39
2.4.4　另外一点说明 ..............................................................................................................40
2.5　方案的世界 ...............................................................................................................................40
2.6　未来展望 ..................................................................................................................................42
2.7　更多信息 ..................................................................................................................................44
第3 章　HTTP 报文 ..........................................................................................................................45
3.1　报文流 ......................................................................................................................................46
3.1.1　报文流入源端服务器 ..................................................................................................46
3.1.2　报文向下游流动 ..........................................................................................................47
3.2　报文的组成部分 .......................................................................................................................47
3.2.1　报文的语法 ..................................................................................................................48
3.2.2　起始行 ..........................................................................................................................50
3.2.3　首部 ..............................................................................................................................53
3.2.4　实体的主体部分 ..........................................................................................................55
3.2.5　版本0.9 的报文 ...........................................................................................................55
3.3　方法 ..........................................................................................................................................56
3.3.1　安全方法 ......................................................................................................................56
3.3.2　GET ...............................................................................................................................56
3.3.3　HEAD ...........................................................................................................................57
3.3.4　PUT ...............................................................................................................................57
3.3.5　POST .............................................................................................................................58
3.3.6　TRACE .........................................................................................................................58
3.3.7　OPTIONS......................................................................................................................60
3.3.8　DELETE .......................................................................................................................60
3.3.9　扩展方法 ......................................................................................................................61
3.4　状态码 ......................................................................................................................................62
3.4.1　100 ～ 199——信息性状态码 ....................................................................................62
3.4.2　200 ～ 299——成功状态码 ........................................................................................63
3.4.3　300 ～ 399——重定向状态码 ....................................................................................64
3.4.4　400 ～ 499——客户端错误状态码 ............................................................................68
3.4.5　500 ～ 599——服务器错误状态码 ............................................................................69
3.5　首部 ..........................................................................................................................................70
3.5.1　通用首部 ......................................................................................................................71
3.5.2　请求首部 ......................................................................................................................72
3.5.3　响应首部 ......................................................................................................................74
3.5.4　实体首部 ......................................................................................................................75
3.6　更多信息 ..................................................................................................................................77
第4 章　连接管理 ..............................................................................................................................79
4.1　TCP 连接..................................................................................................................................80
4.1.1　TCP 的可靠数据管道 ..................................................................................................80
4.1.2　TCP 流是分段的、由IP 分组传送.............................................................................81
4.1.3　保持TCP 连接的正确运行 .........................................................................................82
4.1.4　用TCP 套接字编程 .....................................................................................................84
4.2　对TCP 性能的考虑..................................................................................................................85
4.2.1　HTTP 事务的时延 .......................................................................................................86
4.2.2　性能聚焦区域 ..............................................................................................................87
4.2.3　TCP 连接的握手时延 ..................................................................................................87
4.2.4　延迟确认 ......................................................................................................................88
4.2.5　TCP 慢启动 ..................................................................................................................89
4.2.6　Nagle 算法与TCP_NODELAY ...................................................................................89
4.2.7　TIME_WAIT 累积与端口耗尽 ....................................................................................90
4.3　HTTP 连接的处理 ....................................................................................................................91
4.3.1　常被误解的Connection 首部 .................................................................................91
4.3.2　串行事务处理时延 ......................................................................................................92
4.4　并行连接 ..................................................................................................................................94
4.4.1　并行连接可能会提高页面的加载速度 ......................................................................94
4.4.2　并行连接不一定更快 ..................................................................................................95
4.4.3　并行连接可能让人“感觉”更快一些 ......................................................................95
4.5　持久连接 ..................................................................................................................................96
4.5.1　持久以及并行连接 ......................................................................................................96
4.5.2　HTTP/1.0+ Keep-Alive 连接 .......................................................................................97
4.5.3　keep-Alive 操作 ............................................................................................................98
4.5.4　keep-Alive 选项 ............................................................................................................98
4.5.5　keep-Alive 连接的限制和规则 ....................................................................................99
4.5.6　keep-Alive 和哑代理 ..................................................................................................100
4.5.7　插入Proxy-Connection ......................................................................................102
4.5.8　HTTP/1.1 持久连接 ...................................................................................................104
4.5.9　持久连接的限制和规则 ............................................................................................104
4.6　管道化连接 .............................................................................................................................105
4.7　关闭连接的奥秘 .....................................................................................................................106
4.7.1　“任意”解除连接 ......................................................................................................106
4.7.2　Content-Length 及截尾操作 ...............................................................................107
4.7.3　连接关闭容限、重试以及幂等性 ............................................................................107
4.7.4　正常关闭连接 ............................................................................................................108
4.8　更多信息 ................................................................................................................................110
4.8.1　HTTP 连接 .................................................................................................................110
4.8.2　HTTP 性能问题 .........................................................................................................110
4.8.3　TCP/IP ........................................................................................................................ 111
第二部分　HTTP 结构
第5 章　Web 服务器 ......................................................................................................................115
5.1　各种形状和尺寸的Web 服务器 ............................................................................................116
5.1.1　Web 服务器的实现 ....................................................................................................116
5.1.2　通用软件Web 服务器 ...............................................................................................117
5.1.3　Web 服务器设备 ........................................................................................................117
5.1.4　嵌入式Web 服务器 ...................................................................................................118
5.2　最小的Perl Web 服务器 ........................................................................................................118
5.3　实际的Web 服务器会做些什么 ............................................................................................120
5.4　第一步——接受客户端连接 .................................................................................................121
5.4.1　处理新连接 ................................................................................................................121
5.4.2　客户端主机名识别 ....................................................................................................122
5.4.3　通过ident 确定客户端用户 ......................................................................................122
5.5　第二步——接收请求报文 .....................................................................................................123
5.5.1　报文的内部表示法 ....................................................................................................124
5.5.2　连接的输入/ 输出处理结构 .....................................................................................125
5.6　第三步——处理请求 .............................................................................................................126
5.7　第四步——对资源的映射及访问 .........................................................................................126
5.7.1　docroot ........................................................................................................................127
5.7.2　目录列表 ....................................................................................................................129
5.7.3　动态内容资源的映射 ................................................................................................130
5.7.4　服务器端包含项（SSI） .............................................................................................131
5.7.5　访问控制 ....................................................................................................................131
5.8　第五步——构建响应 .............................................................................................................131
5.8.1　响应实体 ....................................................................................................................131
5.8.2　MIME 类型.................................................................................................................132
5.8.3　重定向 ........................................................................................................................133
5.9　第六步——发送响应 .............................................................................................................134
5.10　第七步——记录日志 ...........................................................................................................134
5.11　更多信息 ...............................................................................................................................134
第6 章　代理 ....................................................................................................................................135
6.1　Web 的中间实体 .....................................................................................................................136
6.1.1　私有和共享代理 ........................................................................................................136
6.1.2　代理与网关的对比 ....................................................................................................137
6.2　为什么使用代理 .....................................................................................................................138
6.3　代理会去往何处 .....................................................................................................................143
6.3.1　代理服务器的部署 ....................................................................................................144
6.3.2　代理的层次结构 ........................................................................................................144
6.3.3　代理是如何获取流量的 ............................................................................................147
6.4　客户端的代理设置 .................................................................................................................148
6.4.1　客户端的代理配置：手工 ........................................................................................149
6.4.2　客户端代理配置：PAC 文件 ....................................................................................149
6.4.3　客户端代理配置：WPAD .........................................................................................150
6.5　与代理请求有关的棘手问题 .................................................................................................151
6.5.1　代理URI 与服务器URI 的不同 ...............................................................................151
6.5.2　与虚拟主机一样的问题 ............................................................................................152
6.5.3　拦截代理会收到部分URI.........................................................................................153
6.5.4　代理既可以处理代理请求，也可以处理服务器请求 ............................................154
6.5.5　转发过程中对URI 的修改........................................................................................154
6.5.6　URI 的客户端自动扩展和主机名解析.....................................................................155
6.5.7　没有代理时URI 的解析............................................................................................155
6.5.8　有显式代理时URI 的解析........................................................................................156
6.5.9　有拦截代理时解析URI.............................................................................................156
6.6　追踪报文 ................................................................................................................................157
6.6.1　Via 首部.....................................................................................................................158
6.6.2　TRACE 方法 ..............................................................................................................162
6.7　代理认证 ................................................................................................................................164
6.8　代理的互操作性 .....................................................................................................................165
6.8.1　处理代理不支持的首部和方法 ................................................................................165
6.8.2　OPTIONS：发现可选特性的支持............................................................................166
6.8.3　Allow 首部 ................................................................................................................167
6.9　更多信息 ................................................................................................................................167
第7 章　缓存 ....................................................................................................................................169
7.1　冗余的数据传输 .....................................................................................................................170
7.2　带宽瓶颈 ................................................................................................................................170
7.3　瞬间拥塞 ................................................................................................................................171
7.4　距离时延 ................................................................................................................................172
7.5　命中和未命中的 .....................................................................................................................173
7.5.1　再验证 ........................................................................................................................173
7.5.2　命中率 ........................................................................................................................175
7.5.3　字节命中率 ................................................................................................................176
7.5.4　区分命中和未命中的情况 ........................................................................................176
7.6　缓存的拓扑结构 .....................................................................................................................177
7.6.1　私有缓存 ....................................................................................................................177
7.6.2　公有代理缓存 ............................................................................................................177
7.6.3　代理缓存的层次结构 ................................................................................................179
7.6.4　网状缓存、内容路由以及对等缓存 ........................................................................180
7.7　缓存的处理步骤 .....................................................................................................................181
7.7.1　第一步——接收 ........................................................................................................181
7.7.2　第二步——解析 ........................................................................................................182
7.7.3　第三步——查找 ........................................................................................................182
7.7.4　第四步——新鲜度检测 ............................................................................................182
7.7.5　第五步——创建响应 ................................................................................................182
7.7.6　第六步——发送 ........................................................................................................183
7.7.7　第七步——日志 ........................................................................................................183
7.7.8　缓存处理流程图 ........................................................................................................183
7.8　保持副本的新鲜 .....................................................................................................................183
7.8.1　文档过期 ....................................................................................................................184
7.8.2　过期日期和年龄 ........................................................................................................185
7.8.3　服务器再验证 ............................................................................................................185
7.8.4　用条件方法进行再验证 ............................................................................................186
7.8.5　If-Modified-Since:Date 再验证 .......................................................................187
7.8.6　If-None-Match􀀀实体标签再验证 .......................................................................189
7.8.7　强弱验证器 ................................................................................................................190
7.8.8　什么时候应该使用实体标签和最近修改日期 ........................................................190
7.9　对缓存能力的控制 .................................................................................................................191
7.9.1　no-Store 与no-Cache 响应首部 .........................................................................191
7.9.2　Max-Age 响应首部 ...................................................................................................192
7.9.3　Expires 响应首部 ...................................................................................................192
7.9.4　Must-Revalidate 响应首部 .................................................................................192
7.9.5　试探性过期 ................................................................................................................193
7.9.6　客户端的新鲜度限制 ................................................................................................194
7.9.7　注意事项 ....................................................................................................................194
7.10　设置缓存控制 .......................................................................................................................195
7.10.1　控制Apache 的HTTP 首部 ....................................................................................195
7.10.2　通过HTTP-EQUIV 控制HTML 缓存 ...................................................................196
7.11　详细算法 ...............................................................................................................................197
7.11.1　年龄和新鲜生存期 ...................................................................................................198
7.11.2　使用期的计算 ...........................................................................................................198
7.11.3　完整的使用期计算算法 ...........................................................................................201
7.11.4　新鲜生存期计算 .......................................................................................................202
7.11.5　完整的服务器—新鲜度算法 ...................................................................................202
7.12　缓存和广告 ...........................................................................................................................204
7.12.1　发布广告者的两难处境 ..........................................................................................204
7.12.2　发布者的响应 ..........................................................................................................204
7.12.3　日志迁移 ..................................................................................................................205
7.12.4　命中计数和使用限制 ..............................................................................................205
7.13　更多信息 ...............................................................................................................................205
第8 章　集成点：网关隧道及中继 .............................................................................................207
8.1　网关 ........................................................................................................................................208
8.2　协议网关 ................................................................................................................................210
8.2.1　HTTP/*：服务器端Web 网关 ..................................................................................211
8.2.2　HTTP/HTTPS：服务器端安全网关 .........................................................................212
8.2.3　HTTPS/HTTP 客户端安全加速器网关 ....................................................................212
8.3　资源网关 ................................................................................................................................213
8.3.1　通用网关接口（CGI） ................................................................................................215
8.3.2　服务器扩展API .........................................................................................................215
8.4　应用程序接口和Web 服务 ....................................................................................................216
8.5　隧道 ........................................................................................................................................217
8.5.1　用CONNECT 建立HTTP 隧道................................................................................217
8.5.2　数据隧道、定时及连接管理 ....................................................................................219
8.5.3　SSL 隧道.....................................................................................................................219
8.5.4　SSL 隧道与HTTP/HTTPS 网关的对比 ...................................................................220
8.5.5　隧道认证 ....................................................................................................................221
8.5.6　隧道的安全性考虑 ....................................................................................................221
8.6　中继 ........................................................................................................................................222
8.7　更多信息 ................................................................................................................................224
第9 章　Web 机器人 ......................................................................................................................225
9.1　爬虫及爬行方式 .....................................................................................................................226
9.1.1　从哪儿开始：根集 ....................................................................................................226
9.1.2　链接的提取以及相对链接的标准化 ........................................................................227
9.1.3　避免环路的出现 ........................................................................................................228
9.1.4　循环与复制 ................................................................................................................228
9.1.5　面包屑留下的痕迹 ....................................................................................................229
9.1.6　别名与机器人环路 ....................................................................................................230
9.1.7　规范化URL ...............................................................................................................230
9.1.8　文件系统连接环路 ....................................................................................................231
9.1.9　动态虚拟Web 空间 ...................................................................................................232
9.1.10　避免循环和重复 ......................................................................................................233
9.2　机器人的HTTP ......................................................................................................................236
9.2.1　识别请求首部 ............................................................................................................236
9.2.2　虚拟主机 ....................................................................................................................236
9.2.3　条件请求 ....................................................................................................................237
9.2.4　对响应的处理 ............................................................................................................238
9.2.5　User-Agent 目标 ....................................................................................................239
9.3　行为不当的机器人 .................................................................................................................239
9.4　拒绝机器人访问 .....................................................................................................................240
9.4.1　拒绝机器人访问标准 ................................................................................................241
9.4.2　Web 站点和robots.txt 文件 .......................................................................................242
9.4.3　robots.txt 文件的格式 ................................................................................................243
9.4.4　其他有关robots.txt 的知识 .......................................................................................246
9.4.5　缓存和robots.txt 的过期 ...........................................................................................246
9.4.6　拒绝机器人访问的Perl 代码 ....................................................................................247
9.4.7　HTML 的robot-control 元标签 ........................................................................249
9.5　机器人的规范 .........................................................................................................................251
9.6　搜索引擎 ................................................................................................................................254
9.6.1　大格局 ........................................................................................................................255
9.6.2　现代搜索引擎结构 ....................................................................................................255
9.6.3　全文索引 ....................................................................................................................255
9.6.4　发布查询请求 ............................................................................................................257
9.6.5　对结果进行排序，并提供查询结果 ........................................................................258
9.6.6　欺诈 ............................................................................................................................258
9.7　更多信息 ................................................................................................................................258
第10 章　HTTP-NG .......................................................................................................................261
10.1　HTTP 发展中存在的问题 ....................................................................................................262
10.2　HTTP-NG 的活动 .................................................................................................................263
10.3　模块化及功能增强 ...............................................................................................................263
10.4　分布式对象 ...........................................................................................................................264
10.5　第一层——报文传输 ...........................................................................................................264
10.6　第二层——远程调用 ...........................................................................................................265
10.7　第三层——Web 应用 ...........................................................................................................265
10.8　WebMUX ..............................................................................................................................265
10.9　二进制连接协议 ...................................................................................................................266
10.10　当前的状态 .........................................................................................................................267
10.11　更多信息 .............................................................................................................................267
第三部分　识别、认证与安全
第11 章　客户端识别与cookie 机制 ........................................................................................271
11.1　个性化接触 ...........................................................................................................................272
11.2　HTTP 首部 ............................................................................................................................273
11.3　客户端IP 地址 .....................................................................................................................274
11.4　用户登录 ...............................................................................................................................275
11.5　胖URL .................................................................................................................................277
11.6　cookie ...................................................................................................................................278
11.6.1　cookie 的类型 .........................................................................................................278
11.6.2　cookie 是如何工作的 .............................................................................................279
11.6.3　cookie 罐：客户端的状态 .....................................................................................280
11.6.4　不同站点使用不同的cookie .................................................................................282
11.6.5　cookie 成分 .............................................................................................................283
11.6.6　cookies 版本0（Netscape） ....................................................................................284
11.6.7　cookies 版本1（RFC 2965） ..................................................................................285
11.6.8　cookie 与会话跟踪 .................................................................................................288
11.6.9　cookie 与缓存 .........................................................................................................290
11.6.10　cookie、安全性和隐私 ........................................................................................291
11.7　更多信息 ...............................................................................................................................292
第12 章　基本认证机制 ................................................................................................................293
12.1　认证 ......................................................................................................................................294
12.1.1　HTTP 的质询/ 响应认证框架 ...............................................................................294
12.1.2　认证协议与首部 .....................................................................................................295
12.1.3　安全域 .....................................................................................................................296
12.2　基本认证 ...............................................................................................................................297
12.2.1　基本认证实例 .........................................................................................................298
12.2.2　Base-64 用户名/ 密码编码 ....................................................................................298
12.2.3　代理认证 .................................................................................................................299
12.3　基本认证的安全缺陷 ...........................................................................................................300
12.4　更多信息 ...............................................................................................................................301
第13 章　摘要认证 .........................................................................................................................303
13.1　摘要认证的改进 ...................................................................................................................304
13.1.1　用摘要保护密码的 .................................................................................................304
13.1.2　单向摘要 .................................................................................................................306
13.1.3　用随机数防止重放攻击 .........................................................................................307
13.1.4　摘要认证的握手机制 .............................................................................................307
13.2　摘要的计算 ...........................................................................................................................308
13.2.1　摘要算法的输入数据 .............................................................................................308
13.2.2　算法H(d) 和KD(s,d) .............................................................................................310
13.2.3　与安全性相关的数据（A1） ..................................................................................310
13.2.4　与报文有关的数据（A2） ......................................................................................310
13.2.5　摘要算法总述 ....................................................................................................................311
13.2.6　摘要认证会话 .........................................................................................................312
13.2.7　预授权 .....................................................................................................................312
13.2.8　随机数的选择 .........................................................................................................315
13.2.9　对称认证 .................................................................................................................315
13.3　增强保护质量 .......................................................................................................................316
13.3.1　报文完整性保护 .....................................................................................................316
13.3.2　摘要认证首部 .........................................................................................................317
13.4　应该考虑的实际问题 ...........................................................................................................317
13.4.1　多重质询 .................................................................................................................318
13.4.2　差错处理 .................................................................................................................318
13.4.3　保护空间 .................................................................................................................318
13.4.4　重写URI .................................................................................................................319
13.4.5　缓存 .........................................................................................................................319
13.5　安全性考虑 ...........................................................................................................................320
13.5.1　首部篡改 .................................................................................................................320
13.5.2　重放攻击 .................................................................................................................320
13.5.3　多重认证机制 .........................................................................................................320
13.5.4　词典攻击 .................................................................................................................321
13.5.5　恶意代理攻击和中间人攻击 .................................................................................321
13.5.6　选择明文攻击 .........................................................................................................321
13.5.7　存储密码 .................................................................................................................322
13.6　更多信息 ...............................................................................................................................322
第14 章　安全HTTP .....................................................................................................................323
14.1　保护HTTP 的安全 ...............................................................................................................324
14.2　数字加密 ...............................................................................................................................326
14.2.1　密码编制的机制与技巧 .........................................................................................326
14.2.2　密码 .........................................................................................................................327
14.2.3　密码机 .....................................................................................................................328
14.2.4　使用了密钥的密码 .................................................................................................328
14.2.5　数字密码 .................................................................................................................328
14.3　对称密钥加密技术 ...............................................................................................................330
14.3.1　密钥长度与枚举攻击 .............................................................................................330
14.3.2　建立共享密钥 .........................................................................................................332
14.4　公开密钥加密技术 ...............................................................................................................332
14.4.1　RSA .........................................................................................................................333
14.4.2　混合加密系统和会话密钥 .....................................................................................334
14.5　数字签名 ...............................................................................................................................334
14.6　数字证书 ...............................................................................................................................336
14.6.1　证书的主要内容 .....................................................................................................336
14.6.2　X.509 v3 证书 .........................................................................................................337
14.6.3　用证书对服务器进行认证 .....................................................................................338
14.7　HTTPS——细节介绍 ...........................................................................................................339
14.7.1　HTTPS 概述 ............................................................................................................339
14.7.2　HTTPS 方案 ............................................................................................................340
14.7.3　建立安全传输 .........................................................................................................341
14.7.4　SSL 握手 .................................................................................................................341
14.7.5　服务器证书 .............................................................................................................343
14.7.6　站点证书的有效性 .................................................................................................344
14.7.7　虚拟主机与证书 .....................................................................................................345
14.8　HTTPS 客户端实例 ..............................................................................................................345
14.8.1　OpenSSL .................................................................................................................346
14.8.2　简单的HTTPS 客户端 ...........................................................................................347
14.8.3　执行OpenSSL 客户端 ...........................................................................................350
14.9　通过代理以隧道形式传输安全流量 ...................................................................................351
14.10　更多信息 .............................................................................................................................353
14.10.1　HTTP 安全性 ........................................................................................................353
14.10.2　SSL 与TLS ...........................................................................................................353
14.10.3　公开密钥基础设施 ...............................................................................................354
14.10.4　数字密码 ...............................................................................................................354
第四部分　实体、编码和国际化
第15 章　实体和编码 .....................................................................................................................357
15.1　报文是箱子，实体是货物 ...................................................................................................359
15.1.1　实体主体 .................................................................................................................360
15.2　Content-Length: 实体的大小 ......................................................................................361
15.2.1　检测截尾 .................................................................................................................361
15.2.2　错误的Content-Length ....................................................................................362
15.2.3　Content-Length 与持久连接 ............................................................................362
15.2.4　内容编码 .................................................................................................................362
15.2.5　确定实体主体长度的规则 .....................................................................................362
15.3　实体摘要 ...............................................................................................................................364
15.4　媒体类型和字符集 ...............................................................................................................364
15.4.1　文本的字符编码 .....................................................................................................365
15.4.2　多部分媒体类型 .....................................................................................................365
15.4.3　多部分表格提交 .....................................................................................................366
15.4.4　多部分范围响应 .....................................................................................................367
15.5　内容编码 ...............................................................................................................................368
15.5.1　内容编码过程 .........................................................................................................368
15.5.2　内容编码类型 .........................................................................................................369
15.5.3　Accept-Encoding 首部 .....................................................................................369
15.6　传输编码和分块编码 ...........................................................................................................371
15.6.1　可靠传输 .................................................................................................................371
15.6.2　Transfer-Encoding 首部 .................................................................................372
15.6.3　分块编码 .................................................................................................................373
15.6.4　内容编码与传输编码的结合 .................................................................................375
15.6.5　传输编码的规则 .....................................................................................................375
15.7　随时间变化的实例 ...............................................................................................................375
15.8　验证码和新鲜度 ...................................................................................................................376
15.8.1　新鲜度 .....................................................................................................................377
15.8.2　有条件的请求与验证码 .........................................................................................378
15.9　范围请求 ...............................................................................................................................380
15.10　差异编码 .............................................................................................................................382
15.11　更多信息 .............................................................................................................................385
第16 章　国际化 ..............................................................................................................................387
16.1　HTTP 对国际性内容的支持 ................................................................................................388
16.2　字符集与HTTP ....................................................................................................................389
16.2.1　字符集是把字符转换为二进制码的编码 .............................................................389
16.2.2　字符集和编码如何工作 .........................................................................................390
16.2.3　字符集不对，字符就不对 .....................................................................................391
16.2.4　标准化的MIME charset 值 ....................................................................................391
16.2.5　Content-Type 首部和Charset 首部以及META 标志 .................................393
16.2.6　Accept-Charset 首部 ........................................................................................393
16.3　多语言字符编码入门 ...........................................................................................................394
16.3.1　字符集术语 .............................................................................................................394
16.3.2　字符集的命名很糟糕 .............................................................................................395
16.3.3　字符 .........................................................................................................................396
16.3.4　字形、连笔以及表示形式 .....................................................................................396
16.3.5　编码后的字符集 .....................................................................................................397
16.3.6　字符编码方案 .........................................................................................................399
16.4　语言标记与HTTP ................................................................................................................402
16.4.1　Content-Language 首部 ...................................................................................402
16.4.2　Accept-Language 首部 .....................................................................................403
16.4.3　语言标记的类型 .....................................................................................................404
16.4.4　子标记 .....................................................................................................................404
16.4.5　大小写 .....................................................................................................................405
16.4.6　IANA 语言标记注册 ..............................................................................................405
16.4.7　第一个子标记——名字空间 .................................................................................405
16.4.8　第二个子标记——名字空间 .................................................................................406
16.4.9　其余子标记——名字空间 .....................................................................................407
16.4.10　配置和语言有关的首选项 ...................................................................................407
16.4.11　语言标记参考表 ...................................................................................................407
16.5　国际化的URI .......................................................................................................................408
16.5.1　全球性的可转抄能力与有意义的字符的较量 .....................................................408
16.5.2　URI 字符集合 .........................................................................................................408
16.5.3　转义和反转义 .........................................................................................................409
16.5.4　转义国际化字符 .....................................................................................................409
16.5.5　URI 中的模态切换 .................................................................................................410
16.6　其他需要考虑的地方 ...........................................................................................................410
16.6.1　首部和不合规范的数据 .........................................................................................410
16.6.2　日期 .........................................................................................................................411
16.6.3　域名 .........................................................................................................................411
16.7　更多信息 ...............................................................................................................................411
16.7.1　附录 .........................................................................................................................411
16.7.2　互联网的国际化 .....................................................................................................411
16.7.3　国际标准 .................................................................................................................412
第17 章　内容协商与转码 ............................................................................................................413
17.1　内容协商技术 .......................................................................................................................414
17.2　客户端驱动的协商 ...............................................................................................................415
17.3　服务器驱动的协商 ...............................................................................................................415
17.3.1　内容协商首部集 .....................................................................................................416
17.3.2　内容协商首部中的质量值 .....................................................................................417
17.3.3　随其他首部集而变化 .............................................................................................417
17.3.4　Apache 中的内容协商 ............................................................................................417
17.3.5　服务器端扩展 .........................................................................................................418
17.4　透明协商 ...............................................................................................................................419
17.4.1　进行缓存与备用候选 .............................................................................................419
17.4.2　Vary 首部 ...............................................................................................................420
17.5　转码 ......................................................................................................................................422
17.5.1　格式转换 .................................................................................................................422
17.5.2　信息综合 .................................................................................................................423
17.5.3　内容注入 .................................................................................................................423
17.5.4　对比转码与静态预生成 .........................................................................................423
17.6　下一步计划 ...........................................................................................................................424
17.7　更多信息 ...............................................................................................................................424
第五部分　内容发布与分发
第18 章　Web 主机托管 ...............................................................................................................429
18.1　主机托管服务 .......................................................................................................................430
18.2　虚拟主机托管 .......................................................................................................................431
18.2.1　虚拟服务器请求缺乏主机信息 .............................................................................432
18.2.2　设法让虚拟主机托管正常工作 .............................................................................433
18.2.3　HTTP/1.1 的Host 首部 ..........................................................................................437
18.3　使网站更可靠 .......................................................................................................................438
18.3.1　镜像的服务器集群 .................................................................................................438
18.3.2　内容分发网络 .........................................................................................................440
18.3.3　CDN 中的反向代理缓存 .......................................................................................440
18.3.4　CDN 中的代理缓存 ...............................................................................................440
18.4　让网站更快 ...........................................................................................................................441
18.5　更多信息 ...............................................................................................................................441
第19 章　发布系统 .........................................................................................................................443
19.1　FrontPage 为支持发布而做的服务器扩展 .........................................................................444
19.1.1　FrontPage 服务器扩展 ...........................................................................................444
19.1.2　FrontPage 术语表 ...................................................................................................445
19.1.3　FrontPage 的RPC 协议 ..........................................................................................445
19.1.4　FrontPage 的安全模型 ...........................................................................................448
19.2　WebDAV 与协作写作 ..........................................................................................................449
19.2.1　WebDAV 的方法.....................................................................................................449
19.2.2　WebDAV 与XML ...................................................................................................450
19.2.3　WebDAV 首部集.....................................................................................................451
19.2.4　WebDAV 的锁定与防止覆写.................................................................................452
19.2.5　LOCK 方法 ...............................................................................................................453
19.2.6　UNLOCK 方法 ..........................................................................................................456
19.2.7　属性和元数据 .........................................................................................................456
19.2.8　PROPFIND 方法 .....................................................................................................457
19.2.9　PROPPATCH 方法 ...................................................................................................459
19.2.10　集合与名字空间管理 ...........................................................................................460
19.2.11　MKCOL 方法...........................................................................................................460
19.2.12　DELETE 方法 ........................................................................................................461
19.2.13　COPY 与MOVE 方法 .............................................................................................462
19.2.14　增强的HTTP/1.1 方法 .........................................................................................465
19.2.15　WebDAV 中的版本管理.......................................................................................466
19.2.16　WebDAV 的未来发展...........................................................................................466
19.3　更多信息 ...............................................................................................................................467
第20 章　重定向与负载均衡 .......................................................................................................469
20.1　为什么要重定向 ...................................................................................................................470
20.2　重定向到何地 .......................................................................................................................471
20.3　重定向协议概览 ...................................................................................................................471
20.4　通用的重定向方法 ...............................................................................................................474
20.4.1　HTTP 重定向 ..........................................................................................................474
20.4.2　DNS 重定向 ............................................................................................................475
20.4.3　任播寻址 .................................................................................................................480
20.4.4　IP MAC 转发 ..........................................................................................................481
20.4.5　IP 地址转发 ............................................................................................................482
20.4.6　网元控制协议 .........................................................................................................484
20.5　代理的重定向方法 ...............................................................................................................485
20.5.1　显式浏览器配置 .....................................................................................................485
20.5.2　代理自动配置 .........................................................................................................485
20.5.3　Web 代理自动发现协议 .........................................................................................487
20.6　缓存重定向方法 ...................................................................................................................492
20.7　因特网缓存协议 ...................................................................................................................496
20.8　缓存阵列路由协议 ...............................................................................................................497
20.9　超文本缓存协议 ...................................................................................................................500
20.9.1　HTCP 认证 ..............................................................................................................502
20.9.2　设置缓存策略 .........................................................................................................503
20.10　更多信息 .............................................................................................................................504
第21 章　日志记录与使用情况跟踪 ..........................................................................................505
21.1　记录的内容 ...........................................................................................................................506
21.2　日志格式 ...............................................................................................................................507
21.2.1　常见日志格式 .........................................................................................................507
21.2.2　组合日志格式 .........................................................................................................508
21.2.3　Netscape 的扩展日志格式 .....................................................................................509
21.2.4　Netscape 扩展2 日志格式 .....................................................................................510
21.2.5　Squid 代理日志格式 ...............................................................................................512
21.3　命中率测量 ...........................................................................................................................515
21.3.1　概述 .........................................................................................................................515
21.3.2　Meter 首部 ..............................................................................................................516
21.4　关于隐私的考虑 ...................................................................................................................517
21.5　更多信息 ...............................................................................................................................518
第六部分　附　录
附录A　URI 方案 ............................................................................................................................521
附录B　HTTP 状态码 ....................................................................................................................529
附录C　HTTP 首部参考 ...............................................................................................................533
附录D　MIME 类型 ........................................................................................................................557
附录E　Base-64 编码 ....................................................................................................................603
附录F　摘要认证 .............................................................................................................................607
附录G　语言标记 ............................................................................................................................615
附录H　MIME 字符集注册表.......................................................................................................641
索引 ......................................................................................................................................................661