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.LinkedHashMap;
020import java.util.List;
021import java.util.Map;
022
023import org.apache.camel.Exchange;
024import org.apache.camel.Processor;
025import org.apache.camel.model.OnExceptionDefinition;
026import org.apache.camel.model.ProcessorDefinitionHelper;
027import org.apache.camel.model.RouteDefinition;
028import org.apache.camel.processor.exceptionpolicy.DefaultExceptionPolicyStrategy;
029import org.apache.camel.processor.exceptionpolicy.ExceptionPolicyKey;
030import org.apache.camel.processor.exceptionpolicy.ExceptionPolicyStrategy;
031import org.apache.camel.spi.RouteContext;
032import org.apache.camel.support.ChildServiceSupport;
033import org.slf4j.Logger;
034import org.slf4j.LoggerFactory;
035
036/**
037 * Support class for {@link ErrorHandler} implementations.
038 *
039 * @version 
040 */
041public abstract class ErrorHandlerSupport extends ChildServiceSupport implements ErrorHandler {
042
043    protected final Logger log = LoggerFactory.getLogger(getClass());
044
045    protected final Map<ExceptionPolicyKey, OnExceptionDefinition> exceptionPolicies = new LinkedHashMap<>();
046    protected ExceptionPolicyStrategy exceptionPolicy = createDefaultExceptionPolicyStrategy();
047
048    public void addExceptionPolicy(RouteContext routeContext, OnExceptionDefinition exceptionType) {
049        if (routeContext != null) {
050            // add error handler as child service so they get lifecycle handled
051            Processor errorHandler = exceptionType.getErrorHandler(routeContext.getRoute().getId());
052            if (errorHandler != null) {
053                addChildService(errorHandler);
054            }
055        }
056
057        List<Class<? extends Throwable>> list = exceptionType.getExceptionClasses();
058        for (Class<? extends Throwable> clazz : list) {
059            String routeId = null;
060            // only get the route id, if the exception type is route scoped
061            if (exceptionType.isRouteScoped()) {
062                RouteDefinition route = ProcessorDefinitionHelper.getRoute(exceptionType);
063                if (route != null) {
064                    routeId = route.getId();
065                }
066            }
067            ExceptionPolicyKey key = new ExceptionPolicyKey(routeId, clazz, exceptionType.getOnWhen());
068            exceptionPolicies.put(key, exceptionType);
069        }
070    }
071
072    /**
073     * Attempts to find the best suited {@link OnExceptionDefinition} to be used for handling the given thrown exception.
074     *
075     * @param exchange  the exchange
076     * @param exception the exception that was thrown
077     * @return the best exception type to handle this exception, <tt>null</tt> if none found.
078     */
079    protected OnExceptionDefinition getExceptionPolicy(Exchange exchange, Throwable exception) {
080        if (exceptionPolicy == null) {
081            throw new IllegalStateException("The exception policy has not been set");
082        }
083
084        return exceptionPolicy.getExceptionPolicy(exceptionPolicies, exchange, exception);
085    }
086
087    /**
088     * Sets the strategy to use for resolving the {@link OnExceptionDefinition} to use
089     * for handling thrown exceptions.
090     */
091    public void setExceptionPolicy(ExceptionPolicyStrategy exceptionPolicy) {
092        if (exceptionPolicy != null) {
093            this.exceptionPolicy = exceptionPolicy;
094        }
095    }
096
097    /**
098     * Creates the default exception policy strategy to use.
099     */
100    public static ExceptionPolicyStrategy createDefaultExceptionPolicyStrategy() {
101        return new DefaultExceptionPolicyStrategy();
102    }
103
104    /**
105     * Whether this error handler supports transacted exchanges or not.
106     */
107    public abstract boolean supportTransacted();
108
109    /**
110     * Whether this error handler handles exhausted errors by moving the exchange to a dead letter channel.
111     */
112    public boolean isDeadLetterChannel() {
113        return false;
114    }
115
116    /**
117     * Gets the output
118     */
119    public abstract Processor getOutput();
120
121}