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.FatalFallbackErrorHandler;
025import org.apache.camel.processor.SendProcessor;
026import org.apache.camel.processor.errorhandler.DeadLetterChannel;
027import org.apache.camel.spi.CamelLogger;
028import org.apache.camel.spi.RouteContext;
029import org.apache.camel.util.StringHelper;
030import org.slf4j.LoggerFactory;
031
032/**
033 * A builder of a
034 * <a href="http://camel.apache.org/dead-letter-channel.html">Dead Letter
035 * Channel</a>
036 */
037public class DeadLetterChannelBuilder extends DefaultErrorHandlerBuilder {
038
039    public DeadLetterChannelBuilder() {
040        // no-arg constructor used by Spring DSL
041    }
042
043    public DeadLetterChannelBuilder(Endpoint deadLetter) {
044        setDeadLetter(deadLetter);
045        // DLC do not log exhausted by default
046        getRedeliveryPolicy().setLogExhausted(false);
047    }
048
049    public DeadLetterChannelBuilder(String uri) {
050        setDeadLetterUri(uri);
051    }
052
053    @Override
054    public Processor createErrorHandler(RouteContext routeContext, Processor processor) throws Exception {
055        validateDeadLetterUri(routeContext);
056
057        DeadLetterChannel answer = new DeadLetterChannel(routeContext.getCamelContext(), processor, getLogger(), getOnRedelivery(), getRedeliveryPolicy(),
058                                                         getExceptionPolicyStrategy(), getFailureProcessor(), getDeadLetterUri(), isDeadLetterHandleNewException(),
059                                                         isUseOriginalMessage(), isUseOriginalBody(), getRetryWhilePolicy(routeContext.getCamelContext()),
060                                                         getExecutorService(routeContext.getCamelContext()), getOnPrepareFailure(), getOnExceptionOccurred());
061        // configure error handler before we can use it
062        configure(routeContext, answer);
063        return answer;
064    }
065
066    @Override
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    @Override
082    public Processor getFailureProcessor() {
083        if (failureProcessor == null) {
084            // wrap in our special safe fallback error handler if sending to
085            // dead letter channel fails
086            Processor child = new SendProcessor(deadLetter, ExchangePattern.InOnly);
087            // force MEP to be InOnly so when sending to DLQ we would not expect
088            // a reply if the MEP was InOut
089            failureProcessor = new FatalFallbackErrorHandler(child, true);
090        }
091        return failureProcessor;
092    }
093
094    protected void validateDeadLetterUri(RouteContext routeContext) {
095        if (deadLetter == null) {
096            StringHelper.notEmpty(deadLetterUri, "deadLetterUri", this);
097            deadLetter = routeContext.getCamelContext().getEndpoint(deadLetterUri);
098            if (deadLetter == null) {
099                throw new NoSuchEndpointException(deadLetterUri);
100            }
101        }
102    }
103
104    @Override
105    protected CamelLogger createLogger() {
106        return new CamelLogger(LoggerFactory.getLogger(DeadLetterChannel.class), LoggingLevel.ERROR);
107    }
108
109    @Override
110    public String toString() {
111        return "DeadLetterChannelBuilder(" + deadLetterUri + ")";
112    }
113}