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.processor;
018
019import java.util.ArrayList;
020import java.util.List;
021
022import org.apache.camel.AsyncCallback;
023import org.apache.camel.AsyncProcessor;
024import org.apache.camel.DelegateProcessor;
025import org.apache.camel.Exchange;
026import org.apache.camel.Navigate;
027import org.apache.camel.Processor;
028import org.apache.camel.support.ServiceSupport;
029import org.apache.camel.util.AsyncProcessorConverterHelper;
030import org.apache.camel.util.AsyncProcessorHelper;
031import org.apache.camel.util.ServiceHelper;
032
033/**
034 * A Delegate pattern which delegates processing to a nested {@link AsyncProcessor} which can
035 * be useful for implementation inheritance when writing an {@link org.apache.camel.spi.Policy}
036 * <p/>
037 * <b>Important:</b> This implementation <b>does</b> support the asynchronous routing engine.
038 * If you are implementing a EIP pattern please use this as the delegate.
039 *
040 * @version
041 * @see DelegateSyncProcessor
042 * @see org.apache.camel.processor.DelegateProcessor
043 */
044public class DelegateAsyncProcessor extends ServiceSupport implements DelegateProcessor, AsyncProcessor, Navigate<Processor> {
045    protected AsyncProcessor processor;
046
047    public DelegateAsyncProcessor() {
048    }
049
050    public DelegateAsyncProcessor(AsyncProcessor processor) {
051        if (processor == this) {
052            throw new IllegalArgumentException("Recursive DelegateAsyncProcessor!");
053        }
054        this.processor = processor;
055    }
056
057    public DelegateAsyncProcessor(Processor processor) {
058        this(AsyncProcessorConverterHelper.convert(processor));
059    }
060
061    @Override
062    public String toString() {
063        return "DelegateAsync[" + processor + "]";
064    }
065
066    public AsyncProcessor getProcessor() {
067        return processor;
068    }
069
070    public void setProcessor(AsyncProcessor processor) {
071        this.processor = processor;
072    }
073
074    public void setProcessor(Processor processor) {
075        this.processor = AsyncProcessorConverterHelper.convert(processor);
076    }
077
078    protected void doStart() throws Exception {
079        ServiceHelper.startServices(processor);
080    }
081
082    protected void doStop() throws Exception {
083        ServiceHelper.stopServices(processor);
084    }
085
086    public void process(Exchange exchange) throws Exception {
087        AsyncProcessorHelper.process(this, exchange);
088    }
089
090    public boolean process(final Exchange exchange, final AsyncCallback callback) {
091        return processor.process(exchange, callback);
092    }
093
094    /**
095     * @deprecated use {@link #process(org.apache.camel.Exchange, org.apache.camel.AsyncCallback)} instead
096     */
097    @Deprecated
098    protected boolean processNext(Exchange exchange, AsyncCallback callback) {
099        throw new UnsupportedOperationException("This method is deprecated, use process(Exchange, AsyncCallback) instead");
100    }
101
102    public boolean hasNext() {
103        return processor != null;
104    }
105
106    public List<Processor> next() {
107        if (!hasNext()) {
108            return null;
109        }
110        List<Processor> answer = new ArrayList<Processor>(1);
111        answer.add(processor);
112        return answer;
113    }
114
115}