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.model;
018
019import java.util.ArrayList;
020import java.util.List;
021import javax.xml.bind.annotation.XmlAccessType;
022import javax.xml.bind.annotation.XmlAccessorType;
023import javax.xml.bind.annotation.XmlRootElement;
024import javax.xml.bind.annotation.XmlTransient;
025
026import org.apache.camel.CamelContext;
027import org.apache.camel.Predicate;
028import org.apache.camel.Processor;
029import org.apache.camel.processor.Pipeline;
030import org.apache.camel.spi.InterceptStrategy;
031import org.apache.camel.spi.RouteContext;
032
033/**
034 * Represents an XML <intercept/> element
035 *
036 * @version 
037 */
038@XmlRootElement(name = "intercept")
039@XmlAccessorType(XmlAccessType.FIELD)
040public class InterceptDefinition extends OutputDefinition<InterceptDefinition> {
041    @XmlTransient
042    protected Processor output;
043    @XmlTransient
044    protected final List<Processor> intercepted = new ArrayList<Processor>();
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 boolean isAbstract() {
066        return true;
067    }
068
069    @Override
070    public boolean isTopLevelOnly() {
071        return true;
072    }
073
074    @Override
075    public Processor createProcessor(final RouteContext routeContext) throws Exception {
076        // create the output processor
077        output = this.createChildProcessor(routeContext, true);
078
079        // add the output as a intercept strategy to the route context so its invoked on each processing step
080        routeContext.getInterceptStrategies().add(new InterceptStrategy() {
081            private Processor interceptedTarget;
082
083            public Processor wrapProcessorInInterceptors(CamelContext context, ProcessorDefinition<?> definition,
084                                                         Processor target, Processor nextTarget) throws Exception {
085                // store the target we are intercepting
086                this.interceptedTarget = target;
087
088                // remember the target that was intercepted
089                intercepted.add(interceptedTarget);
090
091                if (interceptedTarget != null) {
092                    // wrap in a pipeline so we continue routing to the next
093                    List<Processor> list = new ArrayList<Processor>(2);
094                    list.add(output);
095                    list.add(interceptedTarget);
096                    return new Pipeline(context, list);
097                } else {
098                    return output;
099                }
100            }
101
102            @Override
103            public String toString() {
104                return "intercept[" + (interceptedTarget != null ? interceptedTarget : output) + "]";
105            }
106        });
107
108        // remove me from the route so I am not invoked in a regular route path
109        routeContext.getRoute().getOutputs().remove(this);
110        // and return no processor to invoke next from me
111        return null;
112    }
113
114    /**
115     * Applies this interceptor only if the given predicate is true
116     *
117     * @param predicate the predicate
118     * @return the builder
119     */
120    public InterceptDefinition when(Predicate predicate) {
121        WhenDefinition when = new WhenDefinition(predicate);
122        addOutput(when);
123        return this;
124    }
125
126    /**
127     * This method is <b>only</b> for handling some post configuration
128     * that is needed since this is an interceptor, and we have to do
129     * a bit of magic logic to fixup to handle predicates
130     * with or without proceed/stop set as well.
131     */
132    public void afterPropertiesSet() {
133        if (getOutputs().size() == 0) {
134            // no outputs
135            return;
136        }
137
138        ProcessorDefinition<?> first = getOutputs().get(0);
139        if (first instanceof WhenDefinition) {
140            WhenDefinition when = (WhenDefinition) first;
141            // move this outputs to the when, expect the first one
142            // as the first one is the interceptor itself
143            for (int i = 1; i < outputs.size(); i++) {
144                ProcessorDefinition<?> out = outputs.get(i);
145                when.addOutput(out);
146            }
147            // remove the moved from the original output, by just keeping the first one
148            ProcessorDefinition<?> keep = outputs.get(0);
149            clearOutput();
150            outputs.add(keep);
151        }
152    }
153
154    public Processor getInterceptedProcessor(int index) {
155        // avoid out of bounds
156        if (index <= intercepted.size() - 1) {
157            return intercepted.get(index);
158        } else {
159            return null;
160        }
161    }
162}