src/jsr311-api/src/javax/ws/rs/ext/Providers.java

/*
 * 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.
     * @param mediaType the media type of the data that will be read, this will
     * be compared to the values of {@link javax.ws.rs.ConsumeMime} for
     * each candidate reader and only matching readers will be queried.
     * @param type the class of object to be produced.
     * @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 
     * <code>Class.getGenericParameterTypes</code>.
     * @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 
     * <code>Class.getParameterAnnotations</code>.
     * @return a MessageBodyReader that matches the supplied criteria or null
     * if none is found.
     */
    <T> MessageBodyReader<T> getMessageBodyReader(Class<T> type, Type genericType, Annotation annotations[], MediaType mediaType);
    
    
    /**
     * Get a message body writer that matches a set of criteria.
     * @param mediaType the media type of the data that will be written, this will
     * be compared to the values of {@link javax.ws.rs.ProduceMime} for
     * each candidate writer and only matching writers will be queried.
     * @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 
     * <code>Field.getGenericType</code>.
     * @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 
     * <code>Field.getDeclaredAnnotations</code>.
     * @return a MessageBodyReader that matches the supplied criteria or null
     * if none is found.
     */
    <T> MessageBodyWriter<T> getMessageBodyWriter(Class<T> 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.
     */
    <T> ExceptionMapper<T> getExceptionMapper(Class<T> type);

    /**
     * Get a context of a particular type for a class of object. This method 
     * calls {@code getContext(objectType)} on each {@link ContextResolver}
     * with a generic type of {@code contextType} and matching media type
     * capabilities until one returns a non-null context or the list is
     * exhausted.
     * @param contextType the class of context desired
     * @param objectType the class of object for which the context is desired
     * @param mediaType the media type of data for which a context is required.
     * The value is compared to the values of {@link javax.ws.rs.ProduceMime} 
     * for each candidate and only matching providers will be considered. 
     * A null value is equivalent to
     * {@link javax.ws.rs.core.MediaType#WILDCARD_TYPE}.
     * @return a matching context or null if none is found.
     */
    <T> ContextResolver<T> getContextResolver(Class<T> contextType, Class<?> objectType, MediaType mediaType);
}