Shulou(Shulou.com)06/03 Report--

1. Content-Type

MediaType, that is, Internet MediaType, Internet media type; also known as MIME type, in the Http protocol header, Content-Type is used to represent the media type information in a specific request.

Common media formats are as follows:

Text/html: HTML format

Text/plain: plain text format

Text/xml: XML format

P_w_picpath/gif: gif picture format

P_w_picpath/jpeg: jpg picture format

P_w_picpath/png:png picture format

Type of media format that begins with application:

Application/xhtml+xml: XHTML format

Application/xml: XML data format

Application/atom+xml: Atom XML aggregation format

Application/json: JSON data format

Application/pdf: pdf format

Application/msword: Word document format

Application/octet-stream: binary stream data (such as common file downloads)

Application/x-www-form-urlencoded:

The default encType,form form data in is encoded and sent to the server in key/value format (the form's default format for submitting data)

Another common media format is used when uploading files:

Multipart/form-data: this format is required when you need to upload files in the form

These are some of the content-type content formats that we often use in our daily development.

2. About the use of Content-Type type information in Spring MVC

First, let's look at the Class definition in RequestMapping.

@ Target ({ElementType.METHOD, ElementType.TYPE})

@ Retention (RetentionPolicy.RUNTIME)

@ Documented

@ Mapping

Public @ interface RequestMapping {

String [] value () default {}

RequestMethod [] method () default {}

String [] params () default {}

String [] headers () default {}

String [] consumes () default {}

String [] produces () default {}

}

The meaning of each parameter:

Value: specify the actual address of the request, such as / action/info and so on.

Method: specify the method type of the request, such as GET, POST, PUT, DELETE, etc.

Consumes: specifies the submitted content type (Content-Type) to process the request, such as application/json, text/html

Produces: specifies the content type to be returned, only if the (Accept) type in the request request header contains the specified type

Params: specifies that some parameter values must be included in the request for this method to handle the

Headers: specifies that some specified header value must be included in the request for this method to process the request

Among them, consumes and produces use content-typ information to filter information; content-type can be used in headers to filter and judge.

3. Use the example

3.1 headers

@ RequestMapping (value = "/ test", method = RequestMethod.GET, headers= "Referer= http://www.ifeng.com/")"

Public void testHeaders (@ PathVariable String ownerId, @ PathVariable String petId) {

/ / implementation omitted

}

The Headers here can match all the information that can appear in the Header, not limited to Referer information.

3.2 example of params

@ RequestMapping (value = "/ test/ {userId}", method = RequestMethod.GET, params= "myParam=myValue")

Public void findUser (@ PathVariable String userId) {

/ / implementation omitted

}

Processing requests only contains requests named "myParam" with a value of "myValue", which acts as a filter.

3.3 consumes/produces

@ Controller

@ RequestMapping (value = "/ users", method = RequestMethod.POST, consumes= "application/json", produces= "application/json")

@ ResponseBody

Public List addUser (@ RequestBody User userl) {

/ / implementation omitted

Return List users

}

Method handles only requests of type "application/json" with request Content-Type. The produces identity = = > processes requests with "application/json" in the accept header of the request request, implying that the returned content type is application/json

4. Application scenario

Requests submitted by GET or POST:

Content-type: 1. Application/x-www-form-urlencoded:@RequestBody is not required.

2. Mutipart/form-data:@RequestBody cannot handle this format

3. Other formats, such as application/json,application/xml, must be handled with @ RequestBody

The @ ResquestBody annotation enables the http message converter to parse the request body according to content-type

Request submitted in PUT mode:

The above 1 and 3 scenarios must be handled with @ RequestBody, and 2 scenarios are not supported.

Example:

Such as: $.ajax ({

Url: "/ login"

Type: "post"

ContentType: "application/json;charset=UTF-8"

Data:JSON.stringify ({"name": "test", "pass": "123456"})

});

Backend receiving code example:

@ RequestMapping (value= "/ login")

@ ResponseBody

Public ModelAndView loadForm (@ RequestBody Login login) {

/ / implementation omitted

}

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