CachedEntityContainerRequest.java

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package com.sun.jersey.spi.container;

import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

/**
 * A cached entity in-bound HTTP request that caches the entity instance
 * obtained from the adapted container request.
 * <p>
 * A filter may utilize this class if it requires an entity of a specific type
 * and that same type will also be utilized by a resource method.
 *
 * @author Paul.Sandoz@Sun.Com
 */
public class CachedEntityContainerRequest extends AdaptingContainerRequest {

    Object entity;

    public CachedEntityContainerRequest(ContainerRequest acr) {
        super(acr);
    }

    /**
     * Get the entity or a cached instance.
     *
     * @return If called for the first time obtain the entity from the adapting
     *         container request and cache the instance. If called for second or
     *         subsequent time return the cached instance.
     * @throws ClassCastException if the cached entity cannot be cast to the
     *         type requested.
     */
    @Override
    public <T> T getEntity(Class<T> type) throws ClassCastException {
        if (entity == null) {
            T t =  acr.getEntity(type);
            entity = t;
            return t;
        } else {
            return type.cast(entity);
        }
    }

    /**
     * Get the entity or a cached instance.
     *
     * @return If called for the first time obtain the entity from the adapting
     *         container request and cache the instance. If called for second or
     *         subsequent time return the cached instance.
     * @throws ClassCastException if the cached entity cannot be cast to the
     *         type requested.
     */
    @Override
    public <T> T getEntity(Class<T> type, Type genericType, Annotation[] as) throws ClassCastException {
        if (entity == null) {
            T t = acr.getEntity(type, genericType, as);
            entity = t;
            return t;
        } else {
            return type.cast(entity);
        }
    }
}