/*
* Copyright 2002-2009 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* 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.springframework.http.converter.xml;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import org.springframework.http.converter.HttpMessageConversionException;
import org.springframework.util.Assert;
/**
* Abstract base class for {@link org.springframework.http.converter.HttpMessageConverter HttpMessageConverters} that
* use JAXB2. Creates {@link JAXBContext} object lazily.
*
* @author Arjen Poutsma
* @since 3.0
*/
public abstract class AbstractJaxb2HttpMessageConverter<T> extends AbstractXmlHttpMessageConverter<T> {
private final ConcurrentMap<Class, JAXBContext> jaxbContexts = new ConcurrentHashMap<Class, JAXBContext>();
/**
* Creates a new {@link Marshaller} for the given class.
*
* @param clazz the class to create the marshaller for
* @return the {@code Marshaller}
* @throws HttpMessageConversionException in case of JAXB errors
*/
protected final Marshaller createMarshaller(Class clazz) {
try {
JAXBContext jaxbContext = getJaxbContext(clazz);
return jaxbContext.createMarshaller();
}
catch (JAXBException ex) {
throw new HttpMessageConversionException(
"Could not create Marshaller for class [" + clazz + "]: " + ex.getMessage(), ex);
}
}
/**
* Creates a new {@link Unmarshaller} for the given class.
*
* @param clazz the class to create the unmarshaller for
* @return the {@code Unmarshaller}
* @throws HttpMessageConversionException in case of JAXB errors
*/
protected final Unmarshaller createUnmarshaller(Class clazz) throws JAXBException {
try {
JAXBContext jaxbContext = getJaxbContext(clazz);
return jaxbContext.createUnmarshaller();
}
catch (JAXBException ex) {
throw new HttpMessageConversionException(
"Could not create Unmarshaller for class [" + clazz + "]: " + ex.getMessage(), ex);
}
}
/**
* Returns a {@link JAXBContext} for the given class.
*
* @param clazz the class to return the context for
* @return the {@code JAXBContext}
* @throws HttpMessageConversionException in case of JAXB errors
*/
protected final JAXBContext getJaxbContext(Class clazz) {
Assert.notNull(clazz, "'clazz' must not be null");
JAXBContext jaxbContext = jaxbContexts.get(clazz);
if (jaxbContext == null) {
try {
jaxbContext = JAXBContext.newInstance(clazz);
jaxbContexts.putIfAbsent(clazz, jaxbContext);
}
catch (JAXBException ex) {
throw new HttpMessageConversionException(
"Could not instantiate JAXBContext for class [" + clazz + "]: " + ex.getMessage(), ex);
}
}
return jaxbContext;
}
}
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