Using JAX-RS 2.0 context objects to obtain more information about requests

Java API for RESTful Web Services (JAX-RS) 2.0 provides different types of context to application subclasses, root resource classes, and providers. You can use the @Context annotation to inject context objects such as HttpHeaders, UriInfo, HttpServletRequest into class field or method parameter in application subclasses, root resource classes, and providers.

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You can use the following context objects that are available to providers (client and server), resource classes (server only), and Application subclasses (server only):

Context object	Type	Description
`Application`	Class	The instance of the application-supplied `Application` subclass can be injected into a class field or method parameter using the `@Context` annotation. Access to the Application subclass instance allows configuration information to be centralized in that class. Note: This `Application` subclass cannot be injected into the `Application` subclass itself since this would create a circular dependency.
`UriInfo`	Interface	The `UriInfo` interface provides static and dynamic, per-request information, about the components of a request URI.
`HttpHeaders`	Interface	The `HttpHeaders` interface provides access to request header information either in map form or via strongly typed convenience methods.
`Request`	Interface	The `Request` interface allows a caller to determine the best matching representation variant and to evaluate whether the current state of the resource matches any preconditions in the request.
`SecurityContext`	Interface	The `SecurityContext` interface provides access to information about the security context of the current request.
`Providers`	Interface	The `Providers` interface allows for lookup of provider instances based on a set of search criteria.
`ResourceContext`	Interface	The `ResourceContext` interface provides access to instantiation and initialization of resource or subresource classes in the default per-request scope.
`Configuration`	Interface	Both the client and the server runtime configurations are available for injection via `@Context`. These configurations are available for injection in providers (client or server) and resource classes (server only).