REST and Hypermedia

External

• https://www.programmableweb.com

Internal

• Swagger
• API Concepts
• Amazon API Gateway Concepts

API

API Concepts

URL

URL

URI

URI

URN

URN

Resource

A resource is a logical entity that an application can access through a resource path. A resource is a top-level constituent of a REST API. A resource has a number of methods.

Resource Path

Path Parameter

Also referred to as "path variable".

Method

A method corresponds to a REST API request that is submitted by the user of the API to a resource and to the response returned to the user. Methods belong to resources, and are defined by combinations of resource paths and operations. The API methods represent the programming interface between the client and the API.

Request

A Method Request is part of the API's interface with the API's client.

Response

A Method Response is part of the API's interface with the API's client.

HTTP Protocol Semantics within a REST Application Context

Operations

A resource's operations are defined by HTTP verbs:

GET

Get a representation of a resource.

Also see:

HTTP GET Specification

Spring @GetMapping

POST

Create a new resource underneath the current one, based on the given representation. POST is non-idempotent. POST is an unsafe operation.

Also see:

HTTP POST Specification

Spring @PostMapping

PUT

Replace the state of the given resource with the one described in the given representation. Put is an idempotent operation.

Also see:

HTTP PUT Specification

Spring @PutMapping

DELETE

Destroy the resource.

Also see:

HTTP DELETE Specification

Spring @DeleteMapping

PATCH

Defined in RFC 5789.

Updates a resource by modifying part of the state of the given resource based on the given representation. If some bit of resource state is not mentioned in the representation, it should be left unmodified. PATCH is like PUT, but allows for fine-grained changes in resource state.

Also see:

HTTP PATCH Specification

Spring @PatchMapping

HEAD

Get the headers that would be sent along with a representation of this resource, but not the representation itself. This method is mostly used when a client explores the API.

Also see:

HTTP HEAD Specification

OPTIONS

Discover which methods this resource responds to. This method is mostly used when a client explores the API.

Also see:

HTTP OPTIONS Specification

Universal Resource Locator (URL)

Universal Resource Locator

Universal Resource Identifier (URI)

Universal Resource Identifier

Representational State Transfer (REST)

RWA page 32

Multipurpose Internet Mail Extension (MIME)

MIME is an internet standard that extends the format of e-mail to support text in character sets other then ASCII, non-text attachments, such as audio, video, images, application programs, etc., message bodies with multiple parts and header information in non-ASCII characters sets. MIME is specified in six linked RFCs: RFC 2045, RFC 2046, RFC 2047, RFC 4288, RFC 4289 and RFC 2049.

MIME is relevant to HTTP. The content types define by MIME are used in the definition of HTTP content. HTTP clients use MIME content type headers to indicate the desired application to process the specific type of content they send. HTTP servers insert MIME content type information in all their responses.

MIME defines the following headers:

• MIME-Version
• Content-Type
• Content-Disposition
• Content-Transfer-Encoding

Media Type

Wikipedia Media Type

A media type, also called media-type, content type or MIME type is a two-part string identifying the format of a document. Usually, knowing a document's format allows us to parse it. IANA (Internet Assigned Numbers Authority) is the official authority for the standardization and publication of media types. Within the context of REST, the media type is a format of a request and response body. Media types are specified by RFC6838 - Media Type Specifications and Registration Procedures.

The media type string consists of a type and a subtype. The subtype can be further be structured into a tree. A media type can optionally define a suffix and parameters:

type "/" [tree "." ] subtype ["+" suffix] *[";" parameter]

The currently registered types are: "application", "audio", "example", "font", "image", "message", "model", "multipart", "text" and "video".

An HTML file may be designated as:

text/html; charset=UTF-8

Media Type Support

• Media Type Support in Spring
• Media Type Support in OpenAPI