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.processor.DelegateProcessor;
024    import org.apache.camel.Processor;
025    import org.apache.camel.RuntimeCamelException;
026    
027    /**
028     * @version $Revision: 519943 $
029     */
030    public class InterceptorBuilder implements ProcessorFactory {
031        private final List<DelegateProcessor> intercepts = new ArrayList<DelegateProcessor>();
032            private final FromBuilder parent;
033            private FromBuilder target;
034    
035            public InterceptorBuilder(FromBuilder parent) {
036            this.parent = parent;
037            }
038            
039            @Fluent("interceptor")
040            public InterceptorBuilder add(@FluentArg("ref") DelegateProcessor interceptor) {
041                    intercepts.add(interceptor);
042                    return this;
043            }
044            
045            @Fluent(callOnElementEnd=true)
046        public FromBuilder target() {
047            this.target = new FromBuilder(parent);
048            return target;
049        }
050    
051        public Processor createProcessor() throws Exception {
052            
053            // The target is required.
054            if( target == null ) 
055                    throw new RuntimeCamelException("target provided.");
056            
057            // Interceptors are optional
058            DelegateProcessor first=null;
059            DelegateProcessor last=null;
060            for (DelegateProcessor p : intercepts) {
061                if( first == null ) {
062                    first = p;
063                }
064                if( last != null ) {
065                    last.setProcessor(p);
066                }
067                last = p;
068            }
069            
070            Processor p = target.createProcessor();
071            if( last != null ) {
072                    last.setProcessor(p);
073            }
074            return first == null ? p : first;
075        }
076    }