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.spring.spi;
018    
019    import org.apache.camel.Processor;
020    import org.apache.camel.builder.ErrorHandlerBuilder;
021    import org.apache.camel.builder.ErrorHandlerBuilderRef;
022    import org.apache.camel.builder.ErrorHandlerBuilderSupport;
023    import org.apache.camel.spi.RouteContext;
024    import org.apache.camel.spi.TransactedPolicy;
025    import org.apache.camel.util.ObjectHelper;
026    import org.apache.commons.logging.Log;
027    import org.apache.commons.logging.LogFactory;
028    import org.springframework.transaction.PlatformTransactionManager;
029    import org.springframework.transaction.support.TransactionTemplate;
030    
031    /**
032     * Wraps the processor in a Spring transaction
033     *
034     * @version $Revision: 765920 $
035     */
036    public class SpringTransactionPolicy implements TransactedPolicy {
037        private static final transient Log LOG = LogFactory.getLog(SpringTransactionPolicy.class);
038        private TransactionTemplate template;
039        private String propagationBehaviorName;
040        private PlatformTransactionManager transactionManager;
041    
042        /**
043         * Default constructor for easy spring configuration.
044         */
045        public SpringTransactionPolicy() {
046        }
047    
048        public SpringTransactionPolicy(TransactionTemplate template) {
049            this.template = template;
050        }
051    
052        public SpringTransactionPolicy(PlatformTransactionManager transactionManager) {
053            this.transactionManager = transactionManager;
054        }
055    
056        public Processor wrap(RouteContext routeContext, Processor processor) {
057            TransactionErrorHandler answer = new TransactionErrorHandler(getTransactionTemplate());
058            answer.setOutput(processor);
059    
060            // the goal is to configure the error handler builder on the route as a transacted error handler,
061            // either its already a transacted or if not we replace it with a transacted one that we configure here
062            // and wrap the processor in the transacted error handler as we can have transacted routes that change
063            // propagation behavior, eg: from A required -> B -> requiresNew C (advanced use-case)
064            // if we should not support this we do not need to wrap the processor as we only need one transacted error handler
065    
066            // find the existing error handler builder
067            ErrorHandlerBuilder builder = routeContext.getRoute().getErrorHandlerBuilder();
068    
069            // check if its a ref if so then do a lookup
070            if (builder instanceof ErrorHandlerBuilderRef) {
071                // its a reference to a error handler so lookup the reference
072                ErrorHandlerBuilderRef ref = (ErrorHandlerBuilderRef) builder;
073                // only lookup if there was explicit an error handler builder configured
074                // otherwise its just the "default" that has not explicit been configured
075                // and if so then we can safely replace that with our transacted error handler
076                if (ref.isErrorHandlerBuilderConfigued()) {
077                    if (LOG.isDebugEnabled()) {
078                        LOG.debug("Looking up ErrorHandlerBuilder with ref: " + ref.getRef());
079                    }
080                    builder = ref.lookupErrorHandlerBuilder(routeContext);
081                }
082            }
083    
084            if (builder != null && builder.supportTransacted()) {
085                // already a TX error handler then we are good to go
086                if (LOG.isDebugEnabled()) {
087                    LOG.debug("The ErrorHandlerBuilder configured is already a TransactionErrorHandlerBuilder: " + builder);
088                }
089                answer.setExceptionPolicy(builder.getExceptionPolicyStrategy());
090                // configure our answer based on the existing error handler
091                builder.configure(answer);
092            } else {
093                // no transaction error handler builder configure so create a temporary one as we got all
094                // the needed information form the configured builder anyway this allow us to use transacted
095                // routes anway even though the error handler is not transactional, eg ease of configuration
096                if (LOG.isDebugEnabled()) {
097                    if (builder != null) {
098                        LOG.debug("The ErrorHandlerBuilder configured is not a TransactionErrorHandlerBuilder: " + builder);
099                    } else {
100                        LOG.debug("No ErrorHandlerBuilder configured, will use default TransactionErrorHandlerBuilder settings");
101                    }
102                }
103                TransactionErrorHandlerBuilder txBuilder = new TransactionErrorHandlerBuilder();
104                txBuilder.setTransactionTemplate(getTransactionTemplate());
105                txBuilder.setSpringTransactionPolicy(this);
106                if (builder != null) {
107                    // use error handlers from the configured builder
108                    txBuilder.setErrorHandlers(builder.getErrorHandlers());
109                }
110                answer.setExceptionPolicy(txBuilder.getExceptionPolicyStrategy());
111                // configure our answer based on the existing error handler
112                txBuilder.configure(answer);
113    
114                // set the route to use our transacted error handler builder
115                routeContext.getRoute().setErrorHandlerBuilder(txBuilder);
116            }
117    
118            // return with wrapped transacted error handler
119            return answer;
120        }
121    
122        public TransactionTemplate getTransactionTemplate() {
123            if (template == null) {
124                ObjectHelper.notNull(transactionManager, "transactionManager");
125                template = new TransactionTemplate(transactionManager);
126                if (propagationBehaviorName != null) {
127                    template.setPropagationBehaviorName(propagationBehaviorName);
128                }
129            }
130            return template;
131        }
132    
133        public void setTransactionTemplate(TransactionTemplate template) {
134            this.template = template;
135        }
136    
137        public void setTransactionManager(PlatformTransactionManager transactionManager) {
138            this.transactionManager = transactionManager;
139        }
140    
141        public PlatformTransactionManager getTransactionManager() {
142            return transactionManager;
143        }
144    
145        public void setPropagationBehaviorName(String propagationBehaviorName) {
146            this.propagationBehaviorName = propagationBehaviorName;
147        }
148    
149        public String getPropagationBehaviorName() {
150            return propagationBehaviorName;
151        }
152    }