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.impl.converter;
018
019 import org.apache.camel.AsyncCallback;
020 import org.apache.camel.AsyncProcessor;
021 import org.apache.camel.Exchange;
022 import org.apache.camel.Processor;
023 import org.apache.camel.TypeConverter;
024 import org.apache.camel.processor.DelegateProcessor;
025
026 /**
027 * A simple converter that can convert any {@link Processor} to an {@link AsyncProcessor}.
028 * Processing will still occur synchronously but it will provide the required
029 * notifications that the caller expects.
030 *
031 * @version $Revision: 752464 $
032 */
033 public class AsyncProcessorTypeConverter implements TypeConverter {
034
035 private static final class ProcessorToAsyncProcessorBridge extends DelegateProcessor implements AsyncProcessor {
036
037 private ProcessorToAsyncProcessorBridge(Processor processor) {
038 super(processor);
039 }
040
041 public boolean process(Exchange exchange, AsyncCallback callback) {
042 try {
043 processor.process(exchange);
044 } catch (Exception e) {
045 exchange.setException(e);
046 }
047 // false means processing of the exchange asynchronously,
048 callback.done(true);
049 return true;
050 }
051 }
052
053 public <T> T convertTo(Class<T> toType, Object value) {
054 if (value != null) {
055 if (toType.equals(AsyncProcessor.class)) {
056 if (value instanceof AsyncProcessor) {
057 return toType.cast(value);
058 } else if (value instanceof Processor) {
059 // Provide an async bridge to the regular processor.
060 final Processor processor = (Processor)value;
061 return toType.cast(new ProcessorToAsyncProcessorBridge(processor));
062 }
063 }
064 }
065 return null;
066 }
067
068 public <T> T convertTo(Class<T> toType, Exchange exchange, Object value) {
069 return convertTo(toType, value);
070 }
071
072 public static AsyncProcessor convert(Processor value) {
073 if (value instanceof AsyncProcessor) {
074 return (AsyncProcessor)value;
075 }
076 return new ProcessorToAsyncProcessorBridge(value);
077 }
078 }