What is the difference between GET and post? Send a login request using the Post method

What is the difference between GET and POST ? Use the POST method to send a login request .

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<1> http method :

The HTTP protocol defines a number of methods that correspond to different resource operations , the most common of which are the GET and POST methods .

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{GET,POST,OPTIONS,HEAD,PUT,DELETE,TRACE,CONNECT ,PATCH}

increased :P ut

Delete :D elete

change :P ost

Check : GET

}

<2> parameters

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because get and post can do all of the above , in real-world development , We just use get and post method is available .

when interacting with a server , it is sometimes necessary to send some data to the server, such as the need to send a user name and password when logging in .

parameter : refers to the specific data that is passed to the server .

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Themain differences between < 3 > GET and POST are expressed in the transfer of parameters .

"GET":

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The essence of get is that it is more efficient to get data from the server . and a GET request can be cached .

' Note ': network cache data , saved in SQLite database ( path : Nshomedirectory ()).

To view the cache data command line :

' cd files directory ' ( Open file directory )

' ls ' to view the directory under the current file

' sqlite3 cache.db ' Open database

'. Tables ' view the forms in the database

' select * from Cfurl_cache_response; ' View server response cache

' select * from Cfurl_cache_receiver_data; ' View the data cache returned by the server

behind the request URL ? in the form of the parameters issued to the server , the parameters are "parameter name "=" argument value " in the form of splicing , multiple parameters with & separation .

Note : The length of the Get is limited , and different browsers have different length limits , typically between 2 and8K .

}

"POST":

{

The essence of POST is to send data to the server , or to get the result of the server processing , less efficient than get. POST requests cannot be cached , and the form must be resubmitted after each refresh .

the parameters sent to the server are all placed in the ' request body ' ;

in theory, there is no limit to the amount of data that POST transmits .

Note : all data related to user's privacy ( password / bank card number etc. ..) must be delivered by POST .

}

<4> Note : spaces and special symbols such as Chinese are not allowed in the URL .

1>url , All characters must be ASCII code ;

2>url cannot appear in Chinese and special symbols ( such as spaces );

therefore , if Chinese is present in the URL , you need to add a percent translation .

URLString = [URLString stringbyaddingpercentescapesusingencoding:nsutf8stringencoding];

<5> POST Send login request :

Note :

1> with variable request : Nsmutableurlrequest *request = [Nsmutableurlrequest requestwithurl:url];

2> Specify the Request method : Requests. HttpMethod = @ "POST";

3> Set the request body Data : requests. Httpbody = data;

// Instantiate the request body string

NSString *body = [NSString stringWithFormat:@ "username=%@&password=%@",self. Username.text, Self. Password.text];

// convert string to binary data

NSData *data = [Body datausingencoding:nsutf8stringencoding];

4> send asynchronous Network requests .

[Nsurlconnection sendasynchronousrequest:request queue:[nsoperationqueue Mainqueue] completionHandler:^ ( Nsurlresponse *response, NSData *data, Nserror *connectionerror) {

//Nsurlresponse *response: server response

//NSData *data: data returned by the server

//Nserror *connectionerror: connection error Handling

// callback for network request .

}]

}

What is the difference between GET and post? Send a login request using the Post method