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 */
017package 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 */
030public 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}