电子商务restful之http讲解

2】Model与View的选用关系(数据上下文DataContext与View显示)

在MVC的概念着,Model准确点讲是ViewModel而非DomainModel,ViewModel简称呈现Model,重如若将显示的数额融合在一个DataContext中,它来自企业应用架构中的Query端的数据源;一般景色下如此的一个ViewModel不相会常转移,都是基于广大之业务场景抽象出来的一个相比Common的数目上下文;

每当网站型的系统受到,尤其电子商务平台,界面的变非常广阔,几乎每一日还发或改动界面上之有显示情势,同样一致组数据也许在UI上的见格局各不相同;这里虽会形成一个Model与大多独View的结关系,同样一个Promotion(优惠)数据上下文,需要以众多收回类别不同的UI上见,而不同之UI组加尔各答是由不同的View的担当转;

图1:

电子商务 1

得总括爆发一个多少上下文实体在大部分底景下还或会见让广大View使用,所以ASP.NETMVC
需要所有深强的自定义性,一个Model可以任意显示出多受Ui而无相会为此拿ViewModel搞的一律团乱;

顾:一个ViewModel数据实体可能坏酷,倘使以敷衍不同的呈现场景太好将ViewModel举办切割,拉起继续体系,而无是用有着的ViewModel耦合在一个重特大的ViewModel中,这样相会让各类一样浅的询问都会晤波及到部分你这次不相干的习性;

当浏览器为Web服务器发出请求时,它于服务器传递了一个数据块,也不怕是求消息,HTTP请求音信由3有构成:

  • 1.开篇介绍
  • 2.Model同View的应用关系(数据上下文DataContext与View呈现)
  • 3.Metadata头条数据驱动设计(怎么着运用中层元数据来让最后之所作所为)
  • 4.ASP.NETMVC
    ModelMetadata(ModelMetadata元数据如何协助Model与View之间的结关系)

9.5 POST

4.ASP.NETMVC ModelMetadata(ModelMetadata元数据如何支撑Model与View之间的整合关系)

未完待续,敬请关注……

 

作者:王清培

出处:http://www.cnblogs.com/wangiqngpei557/

本文版权归作者和网易共有,欢迎转载,但未经作者同意要保留这么些段子注脚,且在篇章页面

HTTP/1.1 200 OK
响应头(Response
Header)响应头为与请求求头一样包含众多使得之信息,例如服务器类型、日期时、内容类型以及长度等:

开卷目录:

Host:localhost

3.Metadata首数据令设计(如何使中层元数据来教最终之一言一行)

处女数据令设计情势凡过剩经文框架设计情势之一,它同契约式设计些微一脉相承的发;其实框架设计的本质是哪些巧的以一些框架设计格局,不同的语言、平台对格局之动各不相同,不过形式之主导思想一直未碰面转换,不管而什么样规划都得呈现出框架格局的本来面目才行;

在广大之框架设计形式中 style=”text-decoration: underline;”>如:契约式设计、元编程、元数据驱动设计、管道模型、远程代理形式、提供程序模型;首任数据令设计情势是使频率相比高之,因为这复杂度也针锋绝对较逊色所以相比较好达成亲手;其实当许多存世的.NET框架中,如: style=”text-decoration: underline;”>WCF、ASP.NET、Remoting、Winform受都相会映入眼帘Metadata的黑影,可是不必然不得使于命名的时段长Metadata,有诸多的时节吧会师选用Description来代替;

第一届数据一般作为协理数据,它是讲述数据的多少,是的确给分析处理的多寡;既然是描述数据的数量,那么虽然存在它于挺样子上之讲述,描述的角度是呀,描述的框框又是凡啊;

我们不怕以ModelMetadata来讲,在ASP.NETMVC中,Model的采纳方向多给界定在三独操作集合中,第一:请求的数量绑定,第二:数据绑定时的认证,第三:Model的末梢显示;那么ModelMetadata要包含这三独操作集合所需要之百分之百数目,当然为足以通过切割成三组首数据对象模型,通过持续类别包含起来;那么ModelMetadata需要描述三独样子直达之所急需之数量集合,Model本身就是是一中数据,而通过接纳ModelMetadata来抽象的讲述第二独面达到的数码,从六个操作集合角度中富含使用的数额,也就是说五只角度,七只规模;即使你的框架需要有所多独层面,这即使需越来越细化抽象;

图2:

电子商务 2

正式数量通过一个中等的环节转移成元数据,然后交由最后之处理程序去接纳;能够挺清楚的摸底及首数据由及之一个焦点效率,它可以老好之将处理程序与专业数据里解耦,让中的首家数据提供更甚之油滑,通过是当中层元数据,我们得以非常轻松的姣好对元数据开展安排;

咱设没有中间层元数据,操作程序不管怎么规划还会师以及业内数据实体有耦合,而且一旦确保标准数量的纯洁度,不容许连对它们采用持续、特性等重度污染性的侵略,保证完全的POCO(Plain
Old Csharp
Objects)
对象特别不便,假如没IDE的编译时辅助,很麻烦领到出好当运作时行使的数据;这些时大家设急需修改标准元数据的型或者涂改操作程序的逻辑都会面要多依然丢失的对准双方有震慑;

若是接纳初数据我们一齐可以以注脚数据对元数据的概念有迁移到布置文件被去,然后再一次以初数据提供次中扩张读取元数据的源流,能够得将规范数据在另地点还长期的云平台上,对于操作程序来说,大家可将沾元数据的接口提取成瑟维斯(Service)(Service)格局,从其他一个地点读取元数据;

这个各样方案你也许控制永远都非会师用到,不过什么人还要会管某某框架的具备效用都用一边为,系统要求不同,都发或要这么些扩充点;

l        HTTP应答码

1】开篇介绍

即首散文于大家一并来上一下关于Asp.netMvc中的Mode元数据的相关规划与环元数据的一些别对象模型,他们是怎样通过互相和谐来支撑起一个活的界面编程接口;

骨子里提到元数据(Metadata)我们在研有应用框架的上都曾或多或者掉的张了,可能并从未引起你的瞩目;其实在无数行使框架中大家都可以瞥见Matedata的影子,它是一个不胜正确的框架设计格局,俗称:“元数据令设计”,它与近来众企划思想大类似,如:元编程契约式设计,这一个格局目标都是以能够挺好之主宰耦合,发生巨大的恢宏灵活性;元编程让我们可以依照最后之用户挑选动态的起运行软件之代码,而契约式设计能为我们以控制权设立在非常远之地点,从而丰盛特别粒度的操纵扩充性,按照契约设立规则,控制端再以运转时动态的生成出最终要的平整;

style=”font-size: medium;”>通过对这多少个形式深远明,基本上 style=”font-size: medium;”>可以提炼出个别长设计上之金子规则: style=”font-size: medium;”>1. style=”text-decoration: underline;”>将变化点从编译时迁移至运行时; style=”font-size: medium;”> style=”text-decoration: underline;”>2.用变化点从硬编码迁移至配置化;

此间才是一个略的介绍,由于各样一个核心细化下来都会师老卓殊,都会晤包含该方向碰到之好多天地概念、术语和重大的筹划思想,所以这边才是一个简易的介绍,本篇作品会要介绍一下“头数据让设计”编程思想和它究竟好当哪,然后于ASP.NETMVC中其打至怎么着的来意,它以是怎架于向Model与View的迅速桥梁的,让Model与View可以交做1对N的反衬关系,在大型站点中ViewModel一般唯有一定的几乎栽,可是View可能会爆发成千栽,怎样好这种低度适配,这便是从定义模板的法力,当然整个都起以ModelMetadata基础上;

Content-Length:112

See
section 15.1.3 for
security considerations when used for forms.

脚是一个HTTP请求的例证:

Accept-Language:zh-cn

  <html>
<head>

例如:GET/sample/hello.jsp HTTP/1.1

The HEAD method is identical to GET except that the server MUST NOT
return a message-body in the response. The metainformation contained in
the HTTP headers in response to a HEAD request SHOULD be identical to
the information sent in response to a GET request. This method can be
used for obtaining metainformation about the entity implied by the
request without transferring the entity-body itself. This method is
often used for testing hypertext links for validity, accessibility, and
recent modification.

9.1.1 Safe Methods

<title>HTTP响应示例<title>

Accept-Language:zh-cn

Web以最广泛的用之一是电子商务,可以使用Web服务器端程序一旦人人能网络购物,需要指出一点是,缺省景下,通过Internet发送音信是未安全之,倘使某个人刚好截获了卿发给朋友的一律虽信息,他虽能开拓它,假想在中间来您的信用卡号,那会发出多么不好,幸运的是,很多Web服务器和Web浏览器还起开创安全连接的力量,这样它们就好高枕无忧之通信了。

<title>HTTP响应示例<title>

 

 

This specification reserves the method name CONNECT for use with a proxy
that can dynamically switch to being a tunnel (e.g. SSL
tunneling [44]).

HTTP应答与HTTP请求相似,HTTP响应也由于3独片构成,分别是:

User-Agent:Mozila/4.0(compatible;MSIE5.01;Window NT5.0)

A single resource MAY be identified by many different URIs. For example,
an article might have a URI for identifying “the current version” which
is separate from the URI identifying each particular version. In this
case, a PUT request on a general URI might result in several other URIs
being defined by the origin server.

</body>

Hello HTTP!

     
3XX-重定向类(Redirection),表示求没有中标,客户必须用更的动作。

HTTP请求格式

   HTTP应答码也称为状态码,它反映了Web服务器处理HTTP请求状态。HTTP应答码由3个数字组成,其中第一个数字定义了许答码的品类:

HTTP/1.1 does not define how a PUT method affects the state of an origin
server.

上述代码中“GET”代表要方法,“/sample.jsp”表示URI,“HTTP/1.1表示钻探以及商的版。

Host:localhost

Unless otherwise specified for a particular entity-header, the
entity-headers in the PUT request SHOULD be applied to the resource
created or modified by the PUT.

(1)       请求方法URI协议/版本

   Server:Apache Tomcat/5.0.12

回应的首先组成部分凡是商的版本号和应答状态码

part of Hypertext Transfer Protocol —
HTTP/1.1

RFC 2616 Fielding, et al.

(2)    Web浏览器向阳Web服务器发送请求命令

<body>

每当HTTP工作始于前,Web浏览器首先要通过网和Web服务器建立连接,该连是经过TCP来成功的,该协议以及IP协议并构建Internet,即名的TCP/IP协议族,由此Internet又吃名是TCP/IP网络。HTTP是相比TCP更强层次之应用层协议,按照规则,只有低层协议建立之后才,才会举行更层协议的接连,由此,首先使成立TCP连接,一般TCP连接的捧口号是80

伸手的率先执行是“方法URL议/版本”:GET/sample.jsp HTTP/1.1

貌似景色下,一旦Web服务器向浏览器发送了要数据,它就是使关TCP连接,然后一旦浏览器仍旧服务器在其头信息在了这行代码

 

其间, HEAD GET POST OPTIONS PROPFIND是跟朗诵博相关的方法,MKCOL PUT
DELETE LOCK UNLOCK COPY MOVE PROPPATCH是同改相关的方法

9.2 OPTIONS

If the Request-URI is an asterisk (“*”), the OPTIONS request is
intended to apply to the server in general rather than to a specific
resource. Since a server’s communication options typically depend on the
resource, the “*” request is only useful as a “ping” or “no-op” type of
method; it does nothing beyond allowing the client to test the
capabilities of the server. For example, this can be used to test a
proxy for HTTP/1.1 compliance (or lack thereof).

l 响应头(Response Header)

    

TCP连接在殡葬后拿依然保持开拓状态,于是,浏览器可延续通过同样的接连发送请求。保持连续节省了邪每个请求建立新连所待的日子,还节约了网络带来富。

However, it is possible that a sequence of several requests is non-
idempotent, even if all of the methods executed in that sequence are
idempotent. (A sequence is idempotent if a single execution of the
entire sequence always yields a result that is not changed by a
reexecution of all, or part, of that sequence.) For example, a sequence
is non-idempotent if its result depends on a value that is later
modified in the same sequence.

URL完整地指定了要访问的网资源,平常如让闹相互对于服务器的到底目录的绝对目录即可,因而接连坐“/”开始,最终,协议版本讲明了通信过程遭到运用HTTP的本子。

The response to a GET request is cacheable if and only if it meets the
requirements for HTTP caching described in section 13.

GET/sample.jspHTTP/1.1

The PUT method requests that the enclosed entity be stored under the
supplied Request-URI. If the Request-URI refers to an already existing
resource, the enclosed entity SHOULD be considered as a modified version
of the one residing on the origin server. If the Request-URI does not
point to an existing resource, and that URI is capable of being defined
as a new resource by the requesting user agent, the origin server can
create the resource with that URI. If a new resource is created, the
origin server MUST inform the user agent via the 201 (Created) response.
If an existing resource is modified, either the 200 (OK) or 204 (No
Content) response codes SHOULD be sent to indicate successful completion
of the request. If the resource could not be created or modified with
the Request-URI, an appropriate error response SHOULD be given that
reflects the nature of the problem. The recipient of the entity MUST NOT
ignore any Content-* (e.g. Content-Range) headers that it does not
understand or implement and MUST return a 501 (Not Implemented) response
in such cases.

Connection:keep-alive

it MUST send a 301 (Moved Permanently) response; the user agent MAY then
make its own decision regarding whether or not to redirect the request.

username=jinqiao&password=1234

l 响应正文

HTTP/1.1 200 OK

Connection:Keep-Alive

      4XX-客户端错误(Client Error),表示客户端提交的哀告有误 例如:404
NOT

In particular, the convention has been established that the GET and HEAD
methods SHOULD NOT have the significance of taking an action other than
retrieval. These methods ought to be considered “safe”. This allows user
agents to represent other methods, such as POST, PUT and DELETE, in a
special way, so that the user is made aware of the fact that a possibly
unsafe action is being requested.

If the request is valid, the response SHOULD contain the entire request
message in the entity-body, with a Content-Type of “message/http”.
Responses to this method MUST NOT be cached.

The Host request-header field
(section 14.23)
MUST accompany all HTTP/1.1 requests.

                                   
Found,意味着要被所引用的文档不设有。

Content-Length:112

(6)    Web服务器为浏览器发送数据

POST方法是GET方法的一个代格局,它如若为Web服务器交由表单数据,尤其是大批量的数量。POST方法打败了GET方法的一对败笔。通过POST方法提交表单数据平日,数据未是当URL请求的一样局部而是作为正式数量传送给Web服务器,这就摆平了GET方法被的信不可能保密和数据量太小之症结。因而,出于安全的设想同对用户隐私之爱护,平时表单提交时行使POST方法。

The TRACE method is used to invoke a remote, application-layer loop-
back of the request message. The final recipient of the request SHOULD
reflect the message received back to the client as the entity-body of a
200 (OK) response. The final recipient is either the

origin server or the first proxy or gateway to receive a Max-Forwards
value of zero (0) in the request (see section 14.31). A TRACE request
MUST NOT include an entity.

Connection:Keep-Alive

The GET method means retrieve whatever information (in the form of an
entity) is identified by the Request-URI. If the Request-URI refers to a
data-producing process, it is the produced data which shall be returned
as the entity in the response and not the source text of the process,
unless that text happens to be the output of the process.

- Annotation of existing resources;

- Posting a message to a bulletin board, newsgroup, mailing list, or similar group of articles;

- Providing a block of data, such as the result of submitting a form, to a data-handling process;

- Extending a database through an append operation.

(3) 请求正文

Web服务器向浏览器发送头消息后,它会发送一个空白行来表示头信息的殡葬到之也终结,接着,它便以Content-Type应答头信息所讲述的格式发送用户所要的实在多少

  • GET
    通过请求URI拿到资源
  • POST,
    用来补充加新的情节
  • PUT
    用于修改某内容
  • DELETE,
    删去某个内容
  • CONNECT,
    用于代理举办传输,如以SSL
  • OPTIONS
    问询好尽什么样方法
  • PATCH,
    有文档更改
  • PROPFIND, (wedav)
    查看属性
  • PROPPATCH, (wedav)
    安属性
  • MKCOL, (wedav)
    创建集合(文件夹)
  • COPY, (wedav)
    拷贝
  • MOVE, (wedav)
    移动
  • LOCK, (wedav)
    加锁
  • UNLOCK (wedav)
    解锁
  • TRACE
    用以远程诊断服务器
  • HEAD
    好像于GET,
    可是休回body消息,用于检查对象是否存在,以及得到目的的处女数据

   1XX-信息类(Information),表示接受Web浏览器请求,正在越来越的拍卖面临

The OPTIONS method represents a request for information about the
communication options available on the request/response chain identified
by the Request-URI. This method allows the client to determine the
options and/or requirements associated with a resource, or the
capabilities of a server, without implying a resource action or
initiating a resource retrieval.

9 Method Definitions

9.8 TRACE

A 200 response SHOULD include any header fields that indicate optional
features implemented by the server and applicable to that resource
(e.g., Allow), possibly including extensions not defined by this
specification. The response body, if any, SHOULD also include
information about the communication options. The format for such a

据悉HTTP标准,HTTP请求能够行使多伸手方法。例如:HTTP1.1支撑7种要方法:GET、POST、HEAD、OPTIONS、PUT、DELETE和TARCE。在Internet应用中,最常用之艺术是GET和POST。

9.6 PUT

Responses to this method are not cacheable, unless the response includes
appropriate Cache-Control or Expires header fields. However, the 303
(See Other) response can be used to direct the user agent to retrieve a
cacheable resource.

恳请求头和呼吁正文中是一个空行,这么些执行大关键,它意味着求求头已经收尾,接下去的凡要正文。请求正文中可以蕴涵客户提交的查询字符串音讯:

username=jinqiao&password=1234

POST requests MUST obey the message transmission requirements set out in
section 8.2.

每当上述的例子的HTTP请求被,请求的正文只生一行内容。当然,在其进行使被,HTTP请求正文可以分包重复多之情节。

The semantics of the GET method change to a “partial GET” if the request
message includes a Range header field. A partial GET requests that only
part of the entity be transferred, as described in
section 14.35.
The partial GET method is intended to reduce unnecessary network usage
by allowing partially-retrieved entities to be completed without
transferring data already held by the client.

9.7 DELETE

 

9.3 GET

If the request passes through a cache and the Request-URI identifies one
or more currently cached entities, those entries SHOULD be treated as
stale. Responses to this method are not cacheable.

下是一个HTTP响应的例子:

l   请求正文

Accept:image/gif.image/jpeg.*/*

(1)    建立TCP连接

The fundamental difference between the POST and PUT requests is
reflected in the different meaning of the Request-URI. The URI in a POST
request identifies the resource that will handle the enclosed entity.
That resource might be a data-accepting process, a gateway to some other
protocol, or a separate entity that accepts annotations. In contrast,
the URI in a PUT request identifies the entity enclosed with the request
— the user agent knows what URI is intended and the server MUST NOT
attempt to apply the request to some other resource. If the server
desires that the request be applied to a different URI,

<body>

The set of common methods for HTTP/1.1 is defined below. Although this
set can be expanded, additional methods cannot be assumed to share the
same semantics for separately extended clients and servers.

l         GET方法

Content-Type:text/html

If a resource has been created on the origin server, the response SHOULD
be 201 (Created) and contain an entity which describes the status of the
request and refers to the new resource, and a Location header (see
section 14.30).

 响应正文响应正文就是服务器重回的HTML页面:

Server:Apache Tomcat/5.0.12

Implementors should be aware that the software represents the user in
their interactions over the Internet, and should be careful to allow the
user to be aware of any actions they might take which may have an
unexpected significance to themselves or others.

PUT requests MUST obey the message transmission requirements set out in
section 8.2.

Date:Mon,6Oct2003 13:23:42 GMT

9.1 Safe and Idempotent Methods

A sequence that never has side effects is idempotent, by definition
(provided that no concurrent operations are being executed on the same
set of resources).

客户机向服务器发出请求后,服务器会客户机回送应答,

Methods can also have the property of “idempotence” in that (aside from
error or expiration issues) the side-effects of N > 0 identical
requests is the same as for a single request. The methods GET, HEAD, PUT
and DELETE share this property. Also, the methods OPTIONS and TRACE
SHOULD NOT have side effects, and so are inherently idempotent.

Date:Mon,6Oct2003 13:13:33 GMT

Http://127.0.0.1/login.jsp?Name=zhangshi&Age=30&Submit=%cc%E+%BD%BB

A successful response SHOULD be 200 (OK) if the response includes an
entity describing the status, 202 (Accepted) if the action has not yet
been enacted, or 204 (No Content) if the action has been enacted but the
response does not include an entity.

Accept-Encoding:gzip,deflate

The action performed by the POST method might not result in a resource
that can be identified by a URI. In this case, either 200 (OK) or 204
(No Content) is the appropriate response status, depending on whether or
not the response includes an entity that describes the result.

9.1.2 Idempotent Methods

   2XX-成功类(Successful),表示用户请求让科学接受,了然与拍卖例如:200
OK

Last-Moified:Mon,6 Oct 2003 13:23:42 GMT

<html>
<head>

刚刚而客户端会随同请求发送有关自我的音讯相同,服务器也会晤随同应答向用户发送有关其自己的数量和于呼吁的文档。

</body>

  从编程的角度来讲,如若用户通过GET方法提交数据,则数存放于QUERY_STRING环境变量中,而POST方法提交的数据则可以起专业输入流中获取。

Accept-Encoding:gzip,deflate.

The POST method is used to request that the origin server accept the
entity enclosed in the request as a new subordinate of the resource
identified by the Request-URI in the Request-Line. POST is designed to
allow a uniform method to cover the following functions:

HTTP通信机制是以同一遍于完整的HTTP通信过程遭到,Web浏览器与Web服务器之间用形成下列7只步骤:

9.9 CONNECT

If the Request-URI is not an asterisk, the OPTIONS request applies only
to the options that are available when communicating with that resource.

The actual function performed by the POST method is determined by the
server and is usually dependent on the Request-URI. The posted entity is
subordinate to that URI in the same way that a file is subordinate to a
directory containing it, a news article is subordinate to a newsgroup to
which it is posted, or a record is subordinate to a database.

The semantics of the GET method change to a “conditional GET” if the
request message includes an If-Modified-Since, If-Unmodified-Since,
If-Match, If-None-Match, or If-Range header field. A conditional GET
method requests that the entity be transferred only under the
circumstances described by the conditional header field(s). The
conditional GET method is intended to reduce unnecessary network usage
by allowing cached entities to be refreshed without requiring multiple
requests or transferring data already held by the client.

The Max-Forwards request-header field MAY be used to target a specific
proxy in the request chain. When a proxy receives an OPTIONS request on
an absoluteURI for which request forwarding is permitted, the proxy MUST
check for a Max-Forwards field. If the Max-Forwards field-value is zero
(“0”), the proxy MUST NOT forward the message; instead, the proxy SHOULD
respond with its own communication options. If the Max-Forwards
field-value is an integer greater than zero, the proxy MUST decrement
the field-value when it forwards the request. If no Max-Forwards field
is present in the request, then the forwarded request MUST NOT include a
Max-Forwards field.

l   请求头(Request Header)

(4)    Web服务器答应

(2) 请求头(Request Header)

Hello HTTP!

(5)    Web服务器发送应答头信息

The DELETE method requests that the origin server delete the resource
identified by the Request-URI. This method MAY be overridden by human
intervention (or other means) on the origin server. The client cannot be
guaranteed that the operation has been carried out, even if the status
code returned from the origin server indicates that the action has been
completed successfully. However, the server SHOULD NOT indicate success
unless, at the time the response is given, it intends to delete the
resource or move it to an inaccessible location.

恳请求头包含众多关于的客户端环境暨要正文的发由此信息。例如,请求头可以声明浏览器所用的语言,请求正文的长短等。

TRACE allows the client to see what is being received at the other end
of the request chain and use that data for testing or diagnostic
information. The value of the Via header field
(section14.45)
is of particular interest, since it acts as a trace of the request
chain. Use of the Max-Forwards header field allows the client to limit
the length of the request chain, which is useful for testing a chain of
proxies forwarding messages in an infinite loop.

HTTP请求方法本身这里才谈谈GET方法及POST方法

自打点的URL请求中,很轻就可辩认出表单提交的内容。(?之后的情节)其它是因为GET方法提交的数目是作为URL请求的一模一样有据此提交的数据量不可知无限好

Accept:image/gif.image/jpeg,*/*

</head>

</html>

apache2中,可下Limit,LimitExcept进行访问控制的方法包括:GETPOSTPUTDELETECONNECT,OPTIONSPATCHPROPFINDPROPPATCHMKCOLCOPYMOVELOCK,
和 UNLOCK.

Naturally, it is not possible to ensure that the server does not
generate side-effects as a result of performing a GET request; in fact,
some dynamic resources consider that a feature. The important
distinction here is that the user did not request the side-effects, so
therefore cannot be held accountable for them.

If the OPTIONS request includes an entity-body (as indicated by the
presence of Content-Length or Transfer-Encoding), then the media type
MUST be indicated by a Content-Type field. Although this specification
does not define any use for such a body, future extensions to HTTP might
use the OPTIONS body to make more detailed queries on the server. A
server that does not support such an extension MAY discard the request
body.

(3)    Web浏览器发送请求头信息

9.4 HEAD

If the request passes through a cache and the Request-URI identifies one
or more currently cached entities, those entries SHOULD be treated as
stale. Responses to this method are not cacheable.

l         POST方法

</head>

Responses to this method are not cacheable.

(7)    Web服务器闭馆TCP连接

如果成立了TCP连接,Web浏览器就会朝着Web服务器发送请求命令

平安连接

经过Internet提供安全连接最广大的科班是高枕无忧法接层(Secure Sockets
layer,SSl)协议。SSL协议是一个应用层协议(和HTTP一样),用于安全法以Web上交换数据,SSL使用公开密钥编码系统。从精神讲,这表示工作受各样一样在还有一个公然之跟一个个体的密钥。当一着下任何一样着公开密钥进行编码时,只有有卓殊密钥的总人口才可以针对这个解码。总而言之,公开密钥编码提供了同种用于在少在中交换数据的安法,SSL连接起未来,客户与服务器都换成公开密钥,并于进展业务联系此前开展表达,一旦双方的密钥都经验证,就好高枕无忧地交流数据。

响应头和正文中也亟须用空行分隔。  

See
section 15.1.3 for
security considerations.

GET方法是默认的HTTP请求方法,我们一般用GET方法来交付表单数据,可是用GET方法提交的表单数据就通过了简便易行的编码,同时它以当URL的一律片段为Web服务器发送,由此,如若利用GET方法来交付表单数据就在在安全隐患上。例如

      5XX-服务器错误(Server Error)表示服务器不可知形成对要的拍卖:如 500

HTTP(HyperText Transfer
Protocol)是均等拟微机通过网络开展通信的条条框框。总计机专家设计出HTTP,使HTTP客户(如Web浏览器)可以打HTTP服务器(Web服务器)请求音信以及劳务,HTTP近日协和的版本是1.1.HTTP凡是一样种植无状态的协议,无状态是指Web浏览器以及Web服务器之间不欲建立持久的连,这象征当一个客户端向劳动器端发出请求,然后Web服务器重回响应(response),连接就于关了,在劳动器端不保留连接的有关信息.HTTP坚守请求(Request)/应答(Response)模型。Web浏览器为Web服务器发送请求,Web服务器处理要并赶回适当的答应。所有HTTP连接都让协会成一法请求与答复。

l 磋商状态版本代码描述

 

The response to a HEAD request MAY be cacheable in the sense that the
information contained in the response MAY be used to update a previously
cached entity from that resource. If the new field values indicate that
the cached entity differs from the current entity (as would be indicated
by a change in Content-Length, Content-MD5, ETag or Last-Modified), then
the cache MUST treat the cache entry as stale.

l   请求方法URI协议/版本

</html>
合计状态代码描述HTTP响应的第一实施类似于HTTP请求的首先实践,它象征通信所用之合计是HTTP1.1服务器都成之处理了客户端起的请求(200意味着成功):

浏览器发送其要命令下,还要以头消息之款式为Web服务器发送一些另外信息,之后浏览器发送了平等空白行来打招呼服务器,它已经终结了该头音讯的出殡。

HTTP使用内容类型,是依靠Web服务器向Web浏览器重回的公文都起和的有关的品类。所有那么些品种在MIME Internet邮件协议达成模型化,即Web服务器告诉Web浏览器该公文所独具的项目,是HTML文档、GIF格式图像、声音文件如故单独的应用程序。大多数Web浏览器都有所同样多元的但配备的辅应用程序,它们告诉浏览器应该怎么处理Web服务器发送过来的各种内容类型。

     
对于我们Web开发人士来说领会HTTP应答码有助于加强Web应用程序调试的频率与准确性。

body is not defined by this specification, but might be defined by
future extensions to HTTP. Content negotiation MAY be used to select the
appropriate response format. If no response body is included, the
response MUST include a Content-Length field with a field-value of “0”.

User-Agent:Mozila/4.0(compatible:MSIE5.01:Windows NT5.0)

HTTP/1.1 200 OK

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