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 java.util.LinkedHashMap;
020 import java.util.List;
021 import java.util.Map;
022
023 import org.apache.camel.Exchange;
024 import org.apache.camel.Processor;
025 import org.apache.camel.model.OnExceptionDefinition;
026 import org.apache.camel.model.ProcessorDefinitionHelper;
027 import org.apache.camel.model.RouteDefinition;
028 import org.apache.camel.processor.exceptionpolicy.DefaultExceptionPolicyStrategy;
029 import org.apache.camel.processor.exceptionpolicy.ExceptionPolicyKey;
030 import org.apache.camel.processor.exceptionpolicy.ExceptionPolicyStrategy;
031 import org.apache.camel.spi.RouteContext;
032 import org.apache.camel.support.ChildServiceSupport;
033 import org.slf4j.Logger;
034 import org.slf4j.LoggerFactory;
035
036 /**
037 * Support class for {@link ErrorHandler} implementations.
038 *
039 * @version
040 */
041 public 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<ExceptionPolicyKey, OnExceptionDefinition>();
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 }