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This article mainly introduces "how to apply RESTfule style". In daily operation, I believe many people have doubts about how to apply RESTfule style. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful for you to answer the doubts about "how to apply RESTfule style". Next, please follow the editor to study!

What is REST?

REST (English: Representational State Transfer, referred to as REST, meaning: declarative state transition, describes an architectural style of network system, such as web applications).

It is a kind of software architecture style, design style, not a standard, but provides a set of design principles and constraints, it is mainly used for client-side and server-side interactive software. Software designed based on this style can be more brief, more hierarchical, and easier to implement caching and other mechanisms.

It has no usefulness in itself, and its core value lies in how to design a network interface that conforms to the REST style.

What is RESTful?

REST: refers to a set of architectural constraints and principles. The application or design that meets these constraints and principles is RESTful.

Characteristics of RESTful

Resources: an entity on a network, or a specific information on the network. It can be a piece of text, a picture, a song, a service, in short, a concrete existence. You can point to it with a URI (uniform resource locator), and each resource corresponds to a feature URI. To get this resource, you can access its URI, so URI is a unique identifier for each resource.

Presentation layer (Representation): the form in which a resource is presented is called its presentation layer (Representation). For example, text can be represented in txt format, HTML format, XML format, JSON format, or even binary format.

State transition (State Transfer): each request made represents an interaction between the client and the server. HTTP protocol is a stateless protocol, that is, all states are stored on the server side. Therefore, if the client wants to operate on the server, it must have a "State Transfer" on the server side by some means. This transition is based on the presentation layer, so it is the "presentation layer state transition". Specifically, in the HTTP protocol, there are four verbs indicating the mode of operation: GET, POST, PUT, and DELETE. They correspond to four basic operations: GET to obtain resources, POST to create new resources, PUT to update resources, and DELETE to delete resources.

How to design the API of RESTful application?

Path design: after the database design is completed, you can basically determine which resources to operate, and the corresponding paths can also be designed.

Verb design: that is, for the specific operation type of the resource, there are HTTP verbs. The commonly used HTTP verbs are as follows: POST, DELETE, PUT, GET.

RESTful example

/ account/1 HTTP GET: get the account of id=1

/ account/1 HTTP DELETE: delete the account of id=1

/ account/1 HTTP PUT: update the account of id=1

SpringMvc's support for RESTful's URL path variable for RESTful

URL-PATTERN: set to / to facilitate interception of RESTful requests.

@ PathVariable: template variables in URL can be parsed ({id} / {name})

URL: http://localhost:8080/ssm/cyb/item/1/chenyanbinController layer: @ RequestMapping ("{id} / {name}") @ ResponseBodypublic Item queryItemById (@ PathVariable Integer id,@PathVariable String name) {.}

CRUD of RESTful

RequestMapping: by setting the CRUD of the method property, you can map the same URL to different HandlerMethod methods.

The @ GetMapping, @ PostMapping, @ PutMapping, and @ DeleteMapping annotations are the same as the method property settings of the @ RequestMapping annotation.

Resource representation of RESTful

An important feature of RESTful services is that a resource can be represented in multiple forms, which can be implemented in SpringMvc using ContentNegotiatingManager, a content negotiation manager.

There are three ways to negotiate content.

Extensions, such as .json for data in JSON format, and .xml for data in xml format

Request parameter: default is "format"

Request header to set Accept parameters, such as setting Accept to application/json to indicate that you want to format data in JSON format

Now the general RESTful style response data is generally in JSON format, so generally do not use the content negotiation manager, directly use the @ ResponseBody annotation to return the data in JSON format

Static resource access

In the Springmvc.xml file, use the mvc:resources tag as follows:

.

SpringMvc maps mapping to ResourceHttpRequestHandler so that static resources can find the corresponding Handler when they are forwarded by DispatcherServlet.

At this point, the study on "how to use RESTfule style" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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