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 org.apache.camel.Exchange;
020    
021    /**
022     * An object representing the unit of work processing an {@link Exchange}
023     * which allows the use of {@link Synchronization} hooks. This object might map one-to-one with
024     * a transaction in JPA or Spring; or might not.
025     *
026     * @version $Revision: 777808 $
027     */
028    public interface UnitOfWork {
029    
030        /**
031         * Adds a synchronization hook
032         *
033         * @param synchronization  the hook
034         */
035        void addSynchronization(Synchronization synchronization);
036    
037        /**
038         * Removes a synchronization hook
039         *
040         * @param synchronization  the hook
041         */
042        void removeSynchronization(Synchronization synchronization);
043    
044        /**
045         * Handover all the registered synchronizations to the target {@link org.apache.camel.Exchange}.
046         * <p/>
047         * This is used when a route turns into asynchronous and the {@link org.apache.camel.Exchange} that
048         * is continued and routed in the async thread should do the on completion callbacks instead of the
049         * original synchronous thread.
050         * 
051         * @param target  the target exchange
052         */
053        void handoverSynchronization(Exchange target);
054    
055        /**
056         * Invoked when this unit of work has been completed, whether it has failed or completed
057         *
058         * @param exchange the current exchange
059         */
060        void done(Exchange exchange);
061    
062        /**
063         * Returns the unique ID of this unit of work, lazily creating one if it does not yet have one
064         * 
065         * @return the unique ID
066         */
067        String getId();
068    
069        /**
070         * Gets the original IN body this Unit of Work was started with.
071         *
072         * @return the original IN body
073         */
074        Object getOriginalInBody();
075    }