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.builder;
018
019import org.apache.camel.Endpoint;
020import org.apache.camel.ExchangePattern;
021import org.apache.camel.LoggingLevel;
022import org.apache.camel.NoSuchEndpointException;
023import org.apache.camel.Processor;
024import org.apache.camel.processor.DeadLetterChannel;
025import org.apache.camel.processor.FatalFallbackErrorHandler;
026import org.apache.camel.processor.SendProcessor;
027import org.apache.camel.spi.RouteContext;
028import org.apache.camel.util.CamelLogger;
029import org.apache.camel.util.ObjectHelper;
030import org.slf4j.LoggerFactory;
031
032/**
033 * A builder of a <a
034 * href="http://camel.apache.org/dead-letter-channel.html">Dead Letter
035 * Channel</a>
036 *
037 * @version 
038 */
039public class DeadLetterChannelBuilder extends DefaultErrorHandlerBuilder {
040
041    public DeadLetterChannelBuilder() {
042        // no-arg constructor used by Spring DSL
043    }
044
045    public DeadLetterChannelBuilder(Endpoint deadLetter) {
046        setDeadLetter(deadLetter);
047        // DLC do not log exhausted by default
048        getRedeliveryPolicy().setLogExhausted(false);
049    }
050
051    public DeadLetterChannelBuilder(String uri) {
052        setDeadLetterUri(uri);
053    }
054    
055    public Processor createErrorHandler(RouteContext routeContext, Processor processor) throws Exception {
056        validateDeadLetterUri(routeContext);
057
058        DeadLetterChannel answer = new DeadLetterChannel(routeContext.getCamelContext(), processor, getLogger(), getOnRedelivery(), 
059                getRedeliveryPolicy(), getExceptionPolicyStrategy(), getFailureProcessor(), getDeadLetterUri(), isDeadLetterHandleNewException(),
060                isUseOriginalMessage(), getRetryWhilePolicy(routeContext.getCamelContext()), getExecutorService(routeContext.getCamelContext()),
061                getOnPrepareFailure(), getOnExceptionOccurred());
062        // configure error handler before we can use it
063        configure(routeContext, answer);
064        return answer;
065    }
066
067    public boolean supportTransacted() {
068        return false;
069    }
070
071    @Override
072    public ErrorHandlerBuilder cloneBuilder() {
073        DeadLetterChannelBuilder answer = new DeadLetterChannelBuilder();
074        super.cloneBuilder(answer);
075        return answer;
076    }
077
078    // Properties
079    // -------------------------------------------------------------------------
080
081    public Processor getFailureProcessor() {
082        if (failureProcessor == null) {
083            // wrap in our special safe fallback error handler if sending to dead letter channel fails
084            Processor child = new SendProcessor(deadLetter, ExchangePattern.InOnly);
085            // force MEP to be InOnly so when sending to DLQ we would not expect a reply if the MEP was InOut
086            failureProcessor = new FatalFallbackErrorHandler(child, true);
087        }
088        return failureProcessor;
089    }
090
091    protected void validateDeadLetterUri(RouteContext routeContext) {
092        if (deadLetter == null) {
093            ObjectHelper.notEmpty(deadLetterUri, "deadLetterUri", this);
094            deadLetter = routeContext.getCamelContext().getEndpoint(deadLetterUri);
095            if (deadLetter == null) {
096                throw new NoSuchEndpointException(deadLetterUri);
097            }
098        }
099    }
100
101    protected CamelLogger createLogger() {
102        return new CamelLogger(LoggerFactory.getLogger(DeadLetterChannel.class), LoggingLevel.ERROR);
103    }
104
105    @Override
106    public String toString() {
107        return "DeadLetterChannelBuilder(" + deadLetterUri + ")";
108    }
109}