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.model;
018    
019    import java.util.ArrayList;
020    import java.util.List;
021    import javax.xml.bind.annotation.XmlAccessType;
022    import javax.xml.bind.annotation.XmlAccessorType;
023    import javax.xml.bind.annotation.XmlRootElement;
024    import javax.xml.bind.annotation.XmlTransient;
025    
026    import org.apache.camel.Predicate;
027    import org.apache.camel.Processor;
028    import org.apache.camel.processor.Pipeline;
029    import org.apache.camel.spi.InterceptStrategy;
030    import org.apache.camel.spi.RouteContext;
031    
032    /**
033     * Represents an XML <intercept/> element
034     *
035     * @version $Revision: 771227 $
036     */
037    @XmlRootElement(name = "intercept")
038    @XmlAccessorType(XmlAccessType.FIELD)
039    public class InterceptDefinition extends OutputDefinition<ProcessorDefinition> {
040    
041        // TODO: support stop later (its a bit hard as it needs to break entire processing of route)
042    
043        @XmlTransient
044        protected Processor output;
045    
046        public InterceptDefinition() {
047        }
048    
049        @Override
050        public String toString() {
051            return "Intercept[" + getOutputs() + "]";
052        }
053    
054        @Override
055        public String getShortName() {
056            return "intercept";
057        }
058    
059        @Override
060        public String getLabel() {
061            return "intercept";
062        }
063    
064        @Override
065        public Processor createProcessor(final RouteContext routeContext) throws Exception {
066            // create the output processor
067            output = createOutputsProcessor(routeContext);
068    
069            // add the output as a intercept strategy to the route context so its invoked on each processing step
070            routeContext.getInterceptStrategies().add(new InterceptStrategy() {
071                public Processor wrapProcessorInInterceptors(ProcessorDefinition processorDefinition, Processor target, Processor nextTarget) throws Exception {
072                    if (nextTarget != null) {
073                        // wrap in a pipeline so we continue routing to the next
074                        List<Processor> list = new ArrayList<Processor>(2);
075                        list.add(output);
076                        list.add(nextTarget);
077                        return new Pipeline(list);
078                    } else {
079                        return output;
080                    }
081                }
082    
083                @Override
084                public String toString() {
085                    return "intercept[" + output + "]";
086                }
087            });
088    
089            // remove me from the route so I am not invoked in a regular route path
090            routeContext.getRoute().getOutputs().remove(this);
091            // and return no processor to invoke next from me
092            return null;
093        }
094    
095        /**
096         * Applies this interceptor only if the given predicate is true
097         *
098         * @param predicate  the predicate
099         * @return the builder
100         */
101        public ChoiceDefinition when(Predicate predicate) {
102            return choice().when(predicate);
103        }
104    
105        /**
106         * This method is <b>only</b> for handling some post configuration
107         * that is needed from the Spring DSL side as JAXB does not invoke the fluent
108         * builders, so we need to manually handle this afterwards, and since this is
109         * an interceptor it has to do a bit of magic logic to fixup to handle predicates
110         * with or without proceed/stop set as well.
111         */
112        public void afterPropertiesSet() {
113            if (getOutputs().size() == 0) {
114                // no outputs
115                return;
116            }
117    
118            ProcessorDefinition first = getOutputs().get(0);
119            if (first instanceof WhenDefinition) {
120                WhenDefinition when = (WhenDefinition) first;
121                // move this outputs to the when, expect the first one
122                // as the first one is the interceptor itself
123                for (int i = 1; i < outputs.size(); i++) {
124                    ProcessorDefinition out = outputs.get(i);
125                    when.addOutput(out);
126                }
127                // remove the moved from the original output, by just keeping the first one
128                ProcessorDefinition keep = outputs.get(0);
129                clearOutput();
130                outputs.add(keep);
131            }
132        }
133    
134    }