001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.spi;
018    
019    import java.io.InputStream;
020    import java.io.OutputStream;
021    
022    import org.apache.camel.Exchange;
023    
024    /**
025     * Represents a
026     * <a href="http://activemq.apache.org/camel/data-format.html">data format</a>
027     * used to marshal objects to and from streams
028     * such as Java Serialization or using JAXB2 to encode/decode objects using XML
029     * or using SOAP encoding.
030     *
031     * @version $Revision: 1109 $
032     */
033    public interface DataFormat {
034    
035        /**
036         * Marshals the object to the given Stream.
037         *
038         * @param exchange  the current exchange
039         * @param graph     the object to be marshalled
040         * @param stream    the output stream to write the marshalled rersult to
041         * @throws Exception can be thrown
042         */
043        void marshal(Exchange exchange, Object graph, OutputStream stream) throws Exception;
044    
045        /**
046         * Unmarshals the given stream into an object.
047         * <p/>
048         * <b>Notice:</b> The result is set as body on the exchange OUT message.
049         * It is possible to mutate the OUT message provided in the given exchange parameter.
050         * For instance adding headers to the OUT message will be preserved.
051         *
052         * @param exchange    the current exchange
053         * @param stream      the input stream with the object to be unmarshalled
054         * @return            the unmarshalled object
055         * @throws Exception can be thrown
056         */
057        Object unmarshal(Exchange exchange, InputStream stream) throws Exception;
058    }