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;
018    
019    /**
020     * The callback interface for an {@link AsyncProcessor} so that it can
021     * notify you when an {@link Exchange} is done.
022     * <p/>
023     * For example a {@link AsyncProcessor} should invoke the done method when the {@link Exchange} is ready
024     * to be continued routed. This allows to implement asynchronous {@link Producer} which can continue
025     * routing {@link Exchange} when all the data has been gathered. This allows to build non blocking
026     * request/reply communication.
027     *
028     * @version 
029     */
030    public interface AsyncCallback {
031    
032        /**
033         * This method is invoked once the {@link Exchange} is done.
034         * <p/>
035         * If an exception occurred while processing the exchange, the exception field of the
036         * {@link Exchange} being processed will hold the caused exception.
037         *
038         * @param doneSync is <tt>true</tt> if the processing of the {@link Exchange} was completed by a synchronous thread.
039         *                 Otherwise its <tt>false</tt> to indicate it was completed by an asynchronous thread.
040         */
041        void done(boolean doneSync);
042    
043    }