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.processor; 018 019 import org.apache.camel.Exchange; 020 import org.apache.camel.Expression; 021 import org.apache.camel.Processor; 022 023 /** 024 * A <a href="http://camel.apache.org/delayer.html">Delayer</a> which 025 * delays processing the exchange until the correct amount of time has elapsed 026 * using an expression to determine the delivery time. 027 * 028 * @version $Revision: 781923 $ 029 */ 030 public class Delayer extends DelayProcessorSupport { 031 private final Expression delay; 032 033 public Delayer(Processor processor, Expression delay) { 034 super(processor); 035 this.delay = delay; 036 } 037 038 @Override 039 public String toString() { 040 return "Delayer[" + delay + " to: " + getProcessor() + "]"; 041 } 042 043 // Implementation methods 044 // ------------------------------------------------------------------------- 045 046 /** 047 * Waits for an optional time period before continuing to process the 048 * exchange 049 */ 050 protected void delay(Exchange exchange) throws Exception { 051 long time = 0; 052 if (delay != null) { 053 Long longValue = delay.evaluate(exchange, Long.class); 054 if (longValue != null) { 055 time = longValue; 056 } 057 } 058 if (time <= 0) { 059 // no delay 060 return; 061 } 062 063 // now add the current time 064 time += defaultProcessTime(exchange); 065 066 waitUntil(time, exchange); 067 } 068 069 /** 070 * A Strategy Method to allow derived implementations to decide the current 071 * system time or some other default exchange property 072 */ 073 protected long defaultProcessTime(Exchange exchange) { 074 return currentSystemTime(); 075 } 076 077 }