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.util;
018    
019    import java.util.concurrent.CountDownLatch;
020    
021    import org.apache.camel.AsyncCallback;
022    import org.apache.camel.AsyncProcessor;
023    import org.apache.camel.Exchange;
024    
025    /**
026     * Helper methods for AsyncProcessor objects.
027     */
028    public final class AsyncProcessorHelper {
029        
030        private AsyncProcessorHelper() {
031        }
032    
033        /**
034         * Calls the async version of the processor's process method and waits
035         * for it to complete before returning.  This can be used by AsyncProcessor
036         * objects to implement their sync version of the process method.
037         * 
038         * @param processor
039         * @param exchange
040         * @throws Exception
041         */
042        public static void process(AsyncProcessor processor, Exchange exchange) throws Exception {
043            final CountDownLatch latch = new CountDownLatch(1);
044            boolean sync = processor.process(exchange, new AsyncCallback() {
045                public void done(boolean sync) {
046                    if (!sync) {
047                        latch.countDown();
048                    }
049                }
050            });
051            if (!sync) {
052                latch.await();
053            }
054        }
055    }