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.concurrent.ScheduledExecutorService;
020
021import org.apache.camel.CamelContext;
022import org.apache.camel.Exchange;
023import org.apache.camel.Expression;
024import org.apache.camel.Processor;
025import org.apache.camel.Traceable;
026
027/**
028 * A <a href="http://camel.apache.org/delayer.html">Delayer</a> which
029 * delays processing the exchange until the correct amount of time has elapsed
030 * using an expression to determine the delivery time.
031 * <p/>
032 * This implementation will block while waiting.
033 *
034 * @version 
035 */
036public class Delayer extends DelayProcessorSupport implements Traceable {
037    private Expression delay;
038    private long delayValue;
039
040    public Delayer(CamelContext camelContext, Processor processor, Expression delay,
041                   ScheduledExecutorService executorService, boolean shutdownExecutorService) {
042        super(camelContext, processor, executorService, shutdownExecutorService);
043        this.delay = delay;
044    }
045
046    @Override
047    public String toString() {
048        return "Delayer[" + delay + " to: " + getProcessor() + "]";
049    }
050
051    public String getTraceLabel() {
052        return "delay[" + delay + "]";
053    }
054
055    public Expression getDelay() {
056        return delay;
057    }
058
059    public long getDelayValue() {
060        return delayValue;
061    }
062
063    public void setDelay(Expression delay) {
064        this.delay = delay;
065    }
066
067    // Implementation methods
068    // -------------------------------------------------------------------------
069
070    protected long calculateDelay(Exchange exchange) {
071        long time = 0;
072        if (delay != null) {
073            Long longValue = delay.evaluate(exchange, Long.class);
074            if (longValue != null) {
075                delayValue = longValue;
076                time = longValue;
077            } else {
078                delayValue = 0;
079            }
080        }
081        if (time <= 0) {
082            // no delay
083            return 0;
084        }
085
086        return time;
087    }
088
089}