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.io.StringReader;
020    import java.io.StringWriter;
021    import javax.xml.bind.JAXBContext;
022    import javax.xml.bind.JAXBException;
023    import javax.xml.bind.Marshaller;
024    import javax.xml.bind.Unmarshaller;
025    
026    import org.apache.camel.CamelContext;
027    import org.apache.camel.NamedNode;
028    
029    /**
030     * Helper for the Camel {@link org.apache.camel.model model} classes.
031     */
032    public final class ModelHelper {
033    
034        private ModelHelper() {
035            // utility class
036        }
037    
038        /**
039         * Dumps the definition as XML
040         *
041         * @param definition  the definition, such as a {@link org.apache.camel.NamedNode}
042         * @return            the output in XML (is formatted)
043         * @throws JAXBException is throw if error marshalling to XML
044         */
045        public static String dumpModelAsXml(NamedNode definition) throws JAXBException {
046            // create a new jaxb context
047            // must use classloader from CamelContext to have JAXB working
048            JAXBContext jaxbContext = JAXBContext.newInstance(Constants.JAXB_CONTEXT_PACKAGES, CamelContext.class.getClassLoader());
049    
050            Marshaller marshaller = jaxbContext.createMarshaller();
051            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, Boolean.TRUE);
052            StringWriter buffer = new StringWriter();
053            marshaller.marshal(definition, buffer);
054    
055            return buffer.toString();
056        }
057    
058        /**
059         * Marshal the xml to the model definition
060         *
061         * @param xml the xml
062         * @param type the definition type to return, will throw a {@link ClassCastException} if not the expected type
063         * @return the model definition
064         * @throws javax.xml.bind.JAXBException is thrown if error unmarshalling from xml to model
065         */
066        public static <T extends NamedNode> T createModelFromXml(String xml, Class<T> type) throws JAXBException {
067            // create a new jaxb context
068            // must use classloader from CamelContext to have JAXB working
069            JAXBContext jaxbContext = JAXBContext.newInstance(Constants.JAXB_CONTEXT_PACKAGES, CamelContext.class.getClassLoader());
070    
071            StringReader reader = new StringReader(xml);
072            Unmarshaller unmarshaller = jaxbContext.createUnmarshaller();
073            Object result = unmarshaller.unmarshal(reader);
074            reader.close();
075    
076            if (result == null) {
077                throw new JAXBException("Cannot unmarshal to " + type + " using JAXB from XML: " + xml);
078            }
079    
080            return type.cast(result);
081        }
082    }