javax.ws.rs.ext.Providers Maven / Gradle / Ivy
/*
* The contents of this file are subject to the terms
* of the Common Development and Distribution License
* (the "License"). You may not use this file except
* in compliance with the License.
*
* You can obtain a copy of the license at
* http://www.opensource.org/licenses/cddl1.php
* See the License for the specific language governing
* permissions and limitations under the License.
*/
/*
* Providers.java
*
* Created on March 5, 2008, 9:00 AM
*
*/
package javax.ws.rs.ext;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import javax.ws.rs.core.MediaType;
/**
* An injectable interface providing runtime lookup of provider instances.
*
* @see javax.ws.rs.core.Context
* @see MessageBodyReader
* @see MessageBodyWriter
* @see ContextResolver
* @see ExceptionMapper
*/
public interface Providers {
/**
* Get a message body reader that matches a set of criteria. The set of
* readers is first filtered by comparing the supplied value of
* {@code mediaType} with the value of each reader's
* {@link javax.ws.rs.Consumes}, ensuring the supplied value of
* {@code type} is assignable to the generic type of the reader, and
* eliminating those that do not match.
* The list of matching readers is then ordered with those with the best
* matching values of {@link javax.ws.rs.Consumes} (x/y > x/* > */*)
* sorted first. Finally, the
* {@link MessageBodyReader#isReadable}
* method is called on each reader in order using the supplied criteria and
* the first reader that returns {@code true} is selected and returned.
*
* @param type the class of object that is to be read.
* @param genericType the type of object to be produced. E.g. if the
* message body is to be converted into a method parameter, this will be
* the formal type of the method parameter as returned by
* Class.getGenericParameterTypes.
* @param annotations an array of the annotations on the declaration of the
* artifact that will be initialized with the produced instance. E.g. if the
* message body is to be converted into a method parameter, this will be
* the annotations on that parameter returned by
* Class.getParameterAnnotations.
* @param mediaType the media type of the data that will be read.
* @return a MessageBodyReader that matches the supplied criteria or null
* if none is found.
*/
MessageBodyReader getMessageBodyReader(Class type,
Type genericType, Annotation annotations[], MediaType mediaType);
/**
* Get a message body writer that matches a set of criteria. The set of
* writers is first filtered by comparing the supplied value of
* {@code mediaType} with the value of each writer's
* {@link javax.ws.rs.Produces}, ensuring the supplied value of
* {@code type} is assignable to the generic type of the reader, and
* eliminating those that do not match.
* The list of matching writers is then ordered with those with the best
* matching values of {@link javax.ws.rs.Produces} (x/y > x/* > */*)
* sorted first. Finally, the
* {@link MessageBodyWriter#isWriteable}
* method is called on each writer in order using the supplied criteria and
* the first writer that returns {@code true} is selected and returned.
*
* @param type the class of object that is to be written.
* @param genericType the type of object to be written. E.g. if the
* message body is to be produced from a field, this will be
* the declared type of the field as returned by
* Field.getGenericType.
* @param annotations an array of the annotations on the declaration of the
* artifact that will be written. E.g. if the
* message body is to be produced from a field, this will be
* the annotations on that field returned by
* Field.getDeclaredAnnotations.
* @param mediaType the media type of the data that will be written.
* @return a MessageBodyReader that matches the supplied criteria or null
* if none is found.
*/
MessageBodyWriter getMessageBodyWriter(Class type,
Type genericType, Annotation annotations[], MediaType mediaType);
/**
* Get an exception mapping provider for a particular class of exception.
* Returns the provider whose generic type is the nearest superclass of
* {@code type}.
* @param type the class of exception
* @return an {@link ExceptionMapper} for the supplied type or null if none
* is found.
*/
ExceptionMapper getExceptionMapper(Class type);
/**
* Get a context resolver for a particular type of context and media type.
* The set of resolvers is first filtered by comparing the supplied value of
* {@code mediaType} with the value of each resolver's
* {@link javax.ws.rs.Produces}, ensuring the generic type of the context
* resolver is assignable to the supplied value of {@code contextType}, and
* eliminating those that do not match. If only one resolver matches the
* criteria then it is returned. If more than one resolver matches then the
* list of matching resolvers is ordered with those with the best
* matching values of {@link javax.ws.rs.Produces} (x/y > x/* > */*)
* sorted first. A proxy is returned that delegates calls to
* {@link ContextResolver#getContext(java.lang.Class)} to each matching context
* resolver in order and returns the first non-null value it obtains or null
* if all matching context resolvers return null.
*
* @param contextType the class of context desired
* @param mediaType the media type of data for which a context is required.
* @return a matching context resolver instance or null if no matching
* context providers are found.
*/
ContextResolver getContextResolver(Class contextType,
MediaType mediaType);
}