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.RedeliveryPolicy;
027import org.apache.camel.processor.SendProcessor;
028import org.apache.camel.spi.RouteContext;
029import org.apache.camel.util.CamelLogger;
030import org.apache.camel.util.ObjectHelper;
031import org.slf4j.LoggerFactory;
032
033/**
034 * A builder of a <a
035 * href="http://camel.apache.org/dead-letter-channel.html">Dead Letter
036 * Channel</a>
037 *
038 * @version 
039 */
040public class DeadLetterChannelBuilder extends DefaultErrorHandlerBuilder {
041
042    public DeadLetterChannelBuilder() {
043        // no-arg constructor used by Spring DSL
044    }
045
046    public DeadLetterChannelBuilder(Endpoint deadLetter) {
047        setDeadLetter(deadLetter);
048    }
049
050    public DeadLetterChannelBuilder(String uri) {
051        setDeadLetterUri(uri);
052    }
053    
054    public Processor createErrorHandler(RouteContext routeContext, Processor processor) throws Exception {
055        validateDeadLetterUri(routeContext);
056
057        DeadLetterChannel answer = new DeadLetterChannel(routeContext.getCamelContext(), processor, getLogger(), getOnRedelivery(), 
058                getRedeliveryPolicy(), getExceptionPolicyStrategy(), getFailureProcessor(), getDeadLetterUri(), isDeadLetterHandleNewException(),
059                isUseOriginalMessage(), getRetryWhilePolicy(routeContext.getCamelContext()), getExecutorService(routeContext.getCamelContext()));
060        // configure error handler before we can use it
061        configure(routeContext, answer);
062        return answer;
063    }
064
065    public boolean supportTransacted() {
066        return false;
067    }
068
069    @Override
070    public ErrorHandlerBuilder cloneBuilder() {
071        DeadLetterChannelBuilder answer = new DeadLetterChannelBuilder();
072        super.cloneBuilder(answer);
073        return answer;
074    }
075
076    // Properties
077    // -------------------------------------------------------------------------
078
079    public Processor getFailureProcessor() {
080        if (failureProcessor == null) {
081            // wrap in our special safe fallback error handler if sending to dead letter channel fails
082            Processor child = new SendProcessor(deadLetter, ExchangePattern.InOnly);
083            // force MEP to be InOnly so when sending to DLQ we would not expect a reply if the MEP was InOut
084            failureProcessor = new FatalFallbackErrorHandler(child, true);
085        }
086        return failureProcessor;
087    }
088
089    protected void validateDeadLetterUri(RouteContext routeContext) {
090        if (deadLetter == null) {
091            ObjectHelper.notEmpty(deadLetterUri, "deadLetterUri", this);
092            deadLetter = routeContext.getCamelContext().getEndpoint(deadLetterUri);
093            if (deadLetter == null) {
094                throw new NoSuchEndpointException(deadLetterUri);
095            }
096        }
097    }
098
099    @Override
100    protected RedeliveryPolicy createRedeliveryPolicy() {
101        return new RedeliveryPolicy();
102    }
103
104    protected CamelLogger createLogger() {
105        return new CamelLogger(LoggerFactory.getLogger(DeadLetterChannel.class), LoggingLevel.ERROR);
106    }
107
108    @Override
109    public String toString() {
110        return "DeadLetterChannelBuilder(" + deadLetterUri + ")";
111    }
112}