001    /**
002     *
003     * Licensed to the Apache Software Foundation (ASF) under one or more
004     * contributor license agreements.  See the NOTICE file distributed with
005     * this work for additional information regarding copyright ownership.
006     * The ASF licenses this file to You under the Apache License, Version 2.0
007     * (the "License"); you may not use this file except in compliance with
008     * the License.  You may obtain a copy of the License at
009     *
010     * http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.camel;
019    
020    import java.util.Map;
021    
022    /**
023     * Represents the available headers on a message or message exchange.
024     *
025     * @version $Revision: 520502 $
026     */
027    public interface Headers {
028        
029        /**
030         * Accesses a specific header
031         *
032         * @param name
033         * @return object header associated with the name
034         */
035        Object getHeader(String name);
036    
037        /**
038         * Sets a header on the exchange
039         *
040         * @param name  of the header
041         * @param value to associate with the name
042         */
043        void setHeader(String name, Object value);
044    
045        /**
046         * Returns all of the headers associated with the request
047         *
048         * @return all the headers in a Map
049         */
050        Map<String, Object> getHeaders();
051    
052        /**
053         * Creates a copy of the headers so that we can append them to another exchange
054         */
055        Headers copy();
056    }