REST is an
architectural style which is based on web-standards and the HTTP protocol.
In a REST
based architecture everything is a resource. A resource is accessed via a
common interface based on the HTTP standard methods.
In a REST
based architecture you typically have a REST server which provides access to
the resources and a REST client which accesses and modify the REST resources.
Every
resource should support the HTTP common operations. Resources are identified by
global IDs
HTTP methods
The PUT, GET, POST
and DELETE methods are typical used in REST based architectures.
JAX-RS with Jersey
JAX-RS:-
Java defines REST support via the Java Specification Request 311
Jersey :-
contains basically a REST server and a REST client.
On the server side Jersey uses a servlet
which scans predefined classes to identify RESTful resources. Via the web.xml configuration
file for your web application, registers this servlet which is provided by the
Jersey distribution
The base URL of this servlet is:
http://your_domain:port/display-name/url-pattern/path_from_rest_class
This servlet analyzes the incoming HTTP
request and selects the correct class and method to respond to this request.
This selection is based on annotations in the class and methods.
Table 1. JAX-RS annotations
|
Annotation
|
Description
|
|
@PATH(your_path)
|
Sets
the path to base URL + /your_path. The base URL is based on your application
name, the servlet and the URL pattern from the web.xml" configuration
file.
|
|
@POST
|
Indicates
that the following method will answer to a HTTP POST request
|
|
@GET
|
Indicates
that the following method will answer to a HTTP GET request
|
|
@PUT
|
Indicates
that the following method will answer to a HTTP PUT request
|
|
@DELETE
|
Indicates
that the following method will answer to a HTTP DELETE request
|
|
@Produces(MediaType.TEXT_PLAIN
[, more-types ])
|
@Produces
defines which MIME type is delivered by a method annotated with @GET. In the
example text ("text/plain") is produced. Other examples would be
"application/xml" or "application/json".
|
|
@Consumes(type
[, more-types ])
|
@Consumes
defines which MIME type is consumed by this method.
|
|
@PathParam
|
Used
to inject values from the URL into a method parameter. This way you inject
for example the ID of a resource into the method to get the correct object.
|
