001    /**
002     *
003     * Licensed to the Apache Software Foundation (ASF) under one or more
004     * contributor license agreements.  See the NOTICE file distributed with
005     * this work for additional information regarding copyright ownership.
006     * The ASF licenses this file to You under the Apache License, Version 2.0
007     * (the "License"); you may not use this file except in compliance with
008     * the License.  You may obtain a copy of the License at
009     *
010     * http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.camel.builder;
019    
020    import java.util.ArrayList;
021    import java.util.List;
022    
023    import org.apache.camel.Exchange;
024    import org.apache.camel.processor.DelegateProcessor;
025    import org.apache.camel.Processor;
026    import org.apache.camel.RuntimeCamelException;
027    
028    /**
029     * @version $Revision: 519943 $
030     */
031    public class InterceptorBuilder implements ProcessorFactory {
032        private final List<DelegateProcessor> intercepts = new ArrayList<DelegateProcessor>();
033            private final FromBuilder parent;
034            private FromBuilder target;
035    
036            public InterceptorBuilder(FromBuilder parent) {
037            this.parent = parent;
038            }
039            
040            @Fluent("interceptor")
041            public InterceptorBuilder add(@FluentArg("ref") DelegateProcessor interceptor) {
042                    intercepts.add(interceptor);
043                    return this;
044            }
045            
046            @Fluent(callOnElementEnd=true)
047        public FromBuilder target() {
048            this.target = new FromBuilder(parent);
049            return target;
050        }
051    
052        public Processor createProcessor() throws Exception {
053            
054            // The target is required.
055            if( target == null ) 
056                    throw new RuntimeCamelException("target provided.");
057            
058            // Interceptors are optional
059            DelegateProcessor first=null;
060            DelegateProcessor last=null;
061            for (DelegateProcessor p : intercepts) {
062                if( first == null ) {
063                    first = p;
064                }
065                if( last != null ) {
066                    last.setNext(p);
067                }
068                last = p;
069            }
070            
071            Processor p = target.createProcessor();
072            if( last != null ) {
073                    last.setNext(p);
074            }
075            return first == null ? p : first;
076        }
077    }