HTTP consists of two parts: request and response.
1. http request 1. http request format:<Request line>
<Headers>
<Blank line>
[<Request-body>]
In an HTTP request, the first line must be a request line to indicate the request type andResourcesAnd the HTTP Version Used. Next is a header section, which describes additional information to be used by the server. After the header is a blank line, you can add any other data [called the body].
2. Difference Between get and postHTTP defines different methods for interacting with the server. The most basic methods are get and post (Ajax ).DevelopmentOnly get requests and post requests are concerned ).
The get and post methods have the following differences:
(1)
On the client side, the get method submits data through the URL, and the data can be seen in the URL. In the post mode, the data is placed in the HTML
Header.
(2)
Data submitted in get mode can contain a maximum of 1024 bytes, whereas post mode does not.
(3)
Security issues. As mentioned in (1), use get
The parameters are displayed in the address bar, but not post. Therefore, if the data is Chinese and non-sensitive, use get. If the data you enter is not Chinese characters and contains sensitive data, use post as well.
(4)
Secure and idempotent. The so-called security means that this operation is used to instead of modifying information. Idempotence means the same URL
The same results should be returned for multiple requests. The complete definition is not as strict as it looks. In other words, get
Requests generally do not have side effects. Basically, the goal is that when a user opens a link, she can be confident that the resource has not changed from her own perspective. For example, the front pages of news sites are constantly updated. Although the second request will return a different batch of news, this operation is still considered safe and idempotent because it always returns the current news. And vice versa. Post
The request is not that easy. Post
Indicates a request that may change the resources on the server. Taking the news site as an example, the reader's comment on the article should be post
Request implementation, because the site is already different after the annotation is submitted (for example, an annotation is displayed below the article ).
Example of get and post methods:
GET/books /? Name = Professional % 20 Ajax HTTP/1.1
HOST: www.wrox.com
User-Agent: Mozilla/5.0 (windows; U; Windows NT 5.1; en-US; RV: 1.7.6)
Gecko/20050225 Firefox/1.0.1
Connection: keep-alive
Post, HTTP, 1.1
HOST: www.wrox.com
User-Agent: Mozilla/5.0 (windows; U; Windows NT 5.1; en-US; RV: 1.7.6)
Gecko/20050225 Firefox/1.0.1
Content-Type: Application/X-WWW-form-urlencoded
Content-Length: 40
Connection: keep-alive
(---- Null Line here ----)
Name = Professional % 20 Ajax & publisher = Wiley
3. Differences between get and post methods in Form submission are summarized as follows:
(1) get is to get data from the server, and post is to send data to the server.
(2) For the form submission method, the server can only use request. querystring to obtain the data submitted in get mode, and the data submitted in post mode can only be obtained using request. form.
(3) In general, do not use the get method to submit a form because it may cause security problems. For example, if you use the get method in the login form, the user name and password entered by the user will be exposed in the address bar. However, in the paging program, the get method is better than the POST method.
Ii. Http response
1. Http response format:
<Status line>
<Headers>
<Blank line>
[<Response-body>]
The only real difference in the response is that the request information is replaced by the State Information in the first line. Status line describes the requested resources by providing a status code.
HTTP Response instance:
HTTP/1.1 200 OK
Date: sat, 31 Dec 2005 23:59:59 GMT
Content-Type: text/html; charset = ISO-8859-1
Content-Length: 122
<HTML>
<Head>
<Title> wrox homepage </title>
</Head>
<Body>
<! -- Body goes here -->
</Body>
</Html>
2. The most common status codes are:
◆ 200 (OK): The resource is found and everything is normal.
◆ 304 (not modified): The resource has not been modified since the last request. This is usually used for browser caching.
◆ 401 (unauthorized): the client has no permission to access this resource. This usually requires the user to enter the user name and password in the browser to log on to the server.
◆ 403 (Forbidden): the client is not authorized. This is usually because an incorrect user name or password is entered after 401.
◆ 404 (not found): the requested resource does not exist at the specified position.
Http get, post, and soap protocols all run on HTTP.
1) Get: The request parameter is appended to the URL as a sequence (query string) of a key/value pair.
The length of the query string is limited by the web browser and web server (for example, ie supports a maximum of 2048 characters), and is not suitable for transmitting large datasets.
At the same time, it is not safe
2) post: Request Parameters are transmitted in a different part of the HTTP header (Named Entity body). This part is used to transmit form information, so you must
Set Content-Type to application/X-WWW-form-urlencoded.
Post is designed to support user fields on web forms. Its parameters are also transmitted as key/value pairs.
However, it does not support complex data types, because post does not define the semantics and rules of the transmitted data structure.
3) soap: a special version of http post, which follows a special XML Message format.
Set Content-Type to text/XML
Any data can be XML-based
Differences between http post and get
1. Http only supports post and get command modes;
2. Post is designed to store up, while get is designed to fetch from the server. Get can also transmit less data to the server, the reason why get can also transmit data is to design and tell the server what data you actually need. post information is used as the content of the HTTP request, while get is transmitted in the HTTP header;
3. The post and get methods are different in HTTP transmission. Get parameters are transmitted in the HTTP header, while post data is transmitted in the HTTP request content;
4. When post is used to transmit data, it does not need to be displayed in the URL, but the get method must be shown in the URL;
5. Because the get method is limited by the URL length, it can only transmit about 1024 bytes. The size of post data transmission can reach 2 MB. According to Microsoft, Microsoft uses request. form () can receive up to 80 KB of data in IIS 4 and 100 kb in IIS 5;
6. Soap is implemented in the http post mode;
Example:
HTTP GET
Send
GET/demowebservices2.8/service. asmx/cancelorder? Userid = string & Pwd = string & orderconfirmation = string HTTP/1.1
HOST: api.efxnow.com
Reply
HTTP/1.1 200 OK
Content-Type: text/XML; charset = UTF-8
Content-Length: Length
<? XML version = "1.0" encoding = "UTF-8"?>
<Objplaceorderresponse xmlns = "https://api.efxnow.com/webservices2.3">
<Success> Boolean </success>
<Errordescription> string </errordescription>
<Errornumber> int </errornumber>
<Customerorderreference> long </customerorderreference>
<Orderconfirmation> string </orderconfirmation>
<Customerdealref> string </customerdealref>
</Objplaceorderresponse>
HTTP POST
Send
Post/demowebservices2.8/service. asmx/cancelorder HTTP/1.1
HOST: api.efxnow.com
Content-Type: Application/X-WWW-form-urlencoded
Content-Length: Length
Userid = string & Pwd = string & orderconfirmation = string
Reply
HTTP/1.1 200 OK
Content-Type: text/XML; charset = UTF-8
Content-Length: Length
<? XML version = "1.0" encoding = "UTF-8"?>
<Objplaceorderresponse xmlns = "https://api.efxnow.com/webservices2.3">
<Success> Boolean </success>
<Errordescription> string </errordescription>
<Errornumber> int </errornumber>
<Customerorderreference> long </customerorderreference>
<Orderconfirmation> string </orderconfirmation>
<Customerdealref> string </customerdealref>
</Objplaceorderresponse>
HTTP 1.2
Send
Post/demowebservices2.8/service. asmx HTTP/1.1
HOST: api.efxnow.com
Content-Type: Application/soap + XML; charset = UTF-8
Content-Length: Length
<? XML version = "1.0" encoding = "UTF-8"?>
<Soap12: envelope xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance" xmlns: XSD = "http://www.w3.org/2001/XMLSchema" xmlns: soap12 = "http://www.w3.org/2003/05/soap-envelope">
<Soap12: Body>
<Cancelorder xmlns = "https://api.efxnow.com/webservices2.3">
<Userid> string </userid>
<PWD> string </pwd>
<Orderconfirmation> string </orderconfirmation>
</Cancelorder>
</Soap12: Body>
</Soap12: envelope>
Reply
HTTP/1.1 200 OK
Content-Type: Application/soap + XML; charset = UTF-8
Content-Length: Length
<? XML version = "1.0" encoding = "UTF-8"?>
<Soap12: envelope xmlns: xsi = "http://www.w3.org/2001/XMLSchema-instance" xmlns: XSD = "http://www.w3.org/2001/XMLSchema" xmlns: soap12 = "http://www.w3.org/2003/05/soap-envelope">
<Soap12: Body>
<Cancelorderresponse xmlns = "https://api.efxnow.com/webservices2.3">
<Cancelorderresult>
<Success> Boolean </success>
<Errordescription> string </errordescription>
<Errornumber> int </errornumber>
<Customerorderreference> long </customerorderreference>
<Orderconfirmation> string </orderconfirmation>
<Customerdealref> string </customerdealref>
</Cancelorderresult>
</Cancelorderresponse>
</Soap12: Body>
</Soap12: envelope>
*********** **************************************** ***************************/
The article I saw today explains the differences between post and get, and explains the situation in which get and post are used. I reproduced http://hi.baidu.com/gookings/blog/item/092588eefbfac9232cf53405.html.
Summary: if there are not many request parameters, use GET requests when obtaining server resources.
There are too many Request Parameters. If the get limit is exceeded (more accurately, the URL length is limited), post requests are used, and post requests are used to update resources on the server, highly secure post requests with sensitive request parameters.
Performance: GET requests are slightly higher than POST requests.
It is not necessarily true that you end yourself. It only represents your personal opinion.
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