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.servicemix.jbi.util;
018    
019    import javax.xml.transform.dom.DOMSource;
020    
021    import org.w3c.dom.Node;
022    
023    /**
024     * A lazily created source which is only created if its required.
025     * 
026     * @version $Revision: 564607 $
027     */
028    public abstract class LazyDOMSource extends DOMSource {
029    
030        private boolean initialized;
031    
032        public LazyDOMSource() {
033        }
034    
035        public Node getNode() {
036            if (!initialized) {
037                setNode(loadNode());
038                initialized = true;
039            }
040            return super.getNode();
041        }
042    
043        protected abstract Node loadNode();
044    
045    }