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.ArrayList; 020import java.util.LinkedHashMap; 021import java.util.List; 022import java.util.Map; 023 024import org.apache.camel.Exchange; 025import org.apache.camel.Processor; 026import org.apache.camel.RuntimeCamelException; 027import org.apache.camel.model.OnExceptionDefinition; 028import org.apache.camel.model.ProcessorDefinitionHelper; 029import org.apache.camel.model.RouteDefinition; 030import org.apache.camel.processor.exceptionpolicy.DefaultExceptionPolicyStrategy; 031import org.apache.camel.processor.exceptionpolicy.ExceptionPolicyKey; 032import org.apache.camel.processor.exceptionpolicy.ExceptionPolicyStrategy; 033import org.apache.camel.spi.ClassResolver; 034import org.apache.camel.spi.RouteContext; 035import org.apache.camel.support.ChildServiceSupport; 036import org.slf4j.Logger; 037import org.slf4j.LoggerFactory; 038 039/** 040 * Support class for {@link ErrorHandler} implementations. 041 * 042 * @version 043 */ 044public abstract class ErrorHandlerSupport extends ChildServiceSupport implements ErrorHandler { 045 046 protected final Logger log = LoggerFactory.getLogger(getClass()); 047 048 protected final Map<ExceptionPolicyKey, OnExceptionDefinition> exceptionPolicies = new LinkedHashMap<ExceptionPolicyKey, OnExceptionDefinition>(); 049 protected ExceptionPolicyStrategy exceptionPolicy = createDefaultExceptionPolicyStrategy(); 050 051 public void addExceptionPolicy(RouteContext routeContext, OnExceptionDefinition exceptionType) { 052 if (routeContext != null) { 053 // add error handler as child service so they get lifecycle handled 054 Processor errorHandler = exceptionType.getErrorHandler(routeContext.getRoute().getId()); 055 if (errorHandler != null) { 056 addChildService(errorHandler); 057 } 058 059 List<Class<? extends Throwable>> list = null; 060 if (exceptionType.getExceptions() != null && !exceptionType.getExceptions().isEmpty()) { 061 list = createExceptionClasses(exceptionType, routeContext.getCamelContext().getClassResolver()); 062 for (Class<? extends Throwable> clazz : list) { 063 String routeId = null; 064 // only get the route id, if the exception type is route scoped 065 if (exceptionType.isRouteScoped()) { 066 RouteDefinition route = ProcessorDefinitionHelper.getRoute(exceptionType); 067 if (route != null) { 068 routeId = route.getId(); 069 } 070 } 071 ExceptionPolicyKey key = new ExceptionPolicyKey(routeId, clazz, exceptionType.getOnWhen()); 072 exceptionPolicies.put(key, exceptionType); 073 } 074 } 075 } 076 } 077 078 protected List<Class<? extends Throwable>> createExceptionClasses(OnExceptionDefinition exceptionType, ClassResolver resolver) { 079 List<String> list = exceptionType.getExceptions(); 080 List<Class<? extends Throwable>> answer = new ArrayList<>(list.size()); 081 for (String name : list) { 082 try { 083 Class<? extends Throwable> type = resolver.resolveMandatoryClass(name, Throwable.class); 084 answer.add(type); 085 } catch (ClassNotFoundException e) { 086 throw new RuntimeCamelException(e); 087 } 088 } 089 return answer; 090 } 091 092 /** 093 * Attempts to find the best suited {@link OnExceptionDefinition} to be used for handling the given thrown exception. 094 * 095 * @param exchange the exchange 096 * @param exception the exception that was thrown 097 * @return the best exception type to handle this exception, <tt>null</tt> if none found. 098 */ 099 protected OnExceptionDefinition getExceptionPolicy(Exchange exchange, Throwable exception) { 100 if (exceptionPolicy == null) { 101 throw new IllegalStateException("The exception policy has not been set"); 102 } 103 104 return exceptionPolicy.getExceptionPolicy(exceptionPolicies, exchange, exception); 105 } 106 107 /** 108 * Sets the strategy to use for resolving the {@link OnExceptionDefinition} to use 109 * for handling thrown exceptions. 110 */ 111 public void setExceptionPolicy(ExceptionPolicyStrategy exceptionPolicy) { 112 if (exceptionPolicy != null) { 113 this.exceptionPolicy = exceptionPolicy; 114 } 115 } 116 117 /** 118 * Creates the default exception policy strategy to use. 119 */ 120 public static ExceptionPolicyStrategy createDefaultExceptionPolicyStrategy() { 121 return new DefaultExceptionPolicyStrategy(); 122 } 123 124 /** 125 * Whether this error handler supports transacted exchanges or not. 126 */ 127 public abstract boolean supportTransacted(); 128 129 /** 130 * Whether this error handler handles exhausted errors by moving the exchange to a dead letter channel. 131 */ 132 public boolean isDeadLetterChannel() { 133 return false; 134 } 135 136 /** 137 * Gets the output 138 */ 139 public abstract Processor getOutput(); 140 141}