/*
 * Copyright 2002-2012 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.accept;

import java.util.Collections;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.http.MediaType;
import org.springframework.web.context.request.NativeWebRequest;

/**
 * A ContentNegotiationStrategy that returns a fixed content type.
 *
 * @author Rossen Stoyanchev
 * @since 3.2
 */
public class FixedContentNegotiationStrategy implements ContentNegotiationStrategy {

	private static final Log logger = LogFactory.getLog(FixedContentNegotiationStrategy.class);

	private final MediaType defaultContentType;

	/**
	 * Create an instance that always returns the given content type.
	 */
	public FixedContentNegotiationStrategy(MediaType defaultContentType) {
		this.defaultContentType = defaultContentType;
	}

	@Override
	public List<MediaType> resolveMediaTypes(NativeWebRequest webRequest) {
		if (logger.isDebugEnabled()) {
			logger.debug("Requested media types is " + this.defaultContentType + " (based on default MediaType)");
		}
		return Collections.singletonList(this.defaultContentType);
	}

}
