/*

  * Copyright 2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 1.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  * http://www.opensource.org/licenses/ecl1.php

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.ksb.impl.bus;

 import java.io.StringReader;

 import java.io.StringWriter;

 import java.util.HashSet;

 import java.util.Set;

 import javax.xml.bind.JAXBContext;

 import javax.xml.bind.JAXBException;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.core.api.exception.RiceRuntimeException;

 import org.kuali.rice.ksb.api.bus.ServiceConfiguration;

 import org.kuali.rice.ksb.api.bus.support.JavaServiceConfiguration;

 import org.kuali.rice.ksb.api.bus.support.RestServiceConfiguration;

 import org.kuali.rice.ksb.api.bus.support.SoapServiceConfiguration;

 /**

  * This class is meant to be a temporary implementation of serialization operations

  * for {@link ServiceConfiguration} classes.  Coming into Rice 2.0, there is not a

  * "pluggable" spi for dealing with custom service configurations, definitions,

  * connectors, and exporters.  So for now everything is hardcoded and this

  * class creates a hardcoded JAXBContext to perform marshalling/unmarshalling

  * of the standard {@link ServiceConfiguration} classes.

  * 

  * <p>NOTE: JAXBContext is thread-safe, but marshaller/unmarshaller are *NOT* thread-safe.

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 public class ServiceConfigurationSerializationHandler {

         private static final Set<Class<?>> CONFIG_CLASSES_SET = new HashSet<Class<?>>();

         static {

                 CONFIG_CLASSES_SET.add(JavaServiceConfiguration.class);

                 CONFIG_CLASSES_SET.add(SoapServiceConfiguration.class);

                 CONFIG_CLASSES_SET.add(RestServiceConfiguration.class);

         }

         public static String marshallToXml(ServiceConfiguration serviceConfiguration) {

                 if (serviceConfiguration == null) {

                         throw new IllegalArgumentException("serviceConfiguration was null");

                 }

                 if (!CONFIG_CLASSES_SET.contains(serviceConfiguration.getClass())) {

                         throw new IllegalArgumentException("Illegal ServiceConfiguration class: " + serviceConfiguration.getClass());

                 }

                 StringWriter writer = new StringWriter();

                 try {

                         getContext().createMarshaller().marshal(serviceConfiguration, writer);

                 } catch (JAXBException e) {

                         throw new RiceRuntimeException("Failed to marshall ServiceConfiguration to XML: " + serviceConfiguration, e);

                 }

                 return writer.toString();

         }

         public static ServiceConfiguration unmarshallFromXml(String xml) {

                 if (StringUtils.isBlank(xml)) {

                         throw new IllegalArgumentException("xml was null or blank");

                 }

                 try {

                         Object unmarshalled = getContext().createUnmarshaller().unmarshal(new StringReader(xml));

                         if (!(unmarshalled instanceof ServiceConfiguration)) {

                                 throw new RiceRuntimeException("Unmarshalled value was not a valid ServiceConfiguration: " + unmarshalled.getClass());

                         }

                         return (ServiceConfiguration)unmarshalled;

                 } catch (JAXBException e) {

                         throw new RiceRuntimeException("Failed to unmarhsal ServiceConfiguration from XML: " + xml, e);

                 }

         }

         private static JAXBContext getContext() {

                 return ContextHolder.context;

         }

         /**

          * Implements the lazy initialization holder class idiom as per Effective Java item 71.

          */

         private static class ContextHolder {

                 private static final Class<?>[] CONFIG_CLASSES_ARRAY = CONFIG_CLASSES_SET.toArray(new Class<?>[0]);

                 static final JAXBContext context;

                 static {

                         try {

                                 context = JAXBContext.newInstance(CONFIG_CLASSES_ARRAY);

                         } catch (JAXBException e) {

                                 throw new RiceRuntimeException(e);

                         }

                 }

         }

 }