Java tutorial
/* * Copyright 2002-2010 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 jails.http.converter.xml; import jails.http.HttpHeaders; import jails.http.converter.HttpMessageNotReadableException; import jails.http.converter.HttpMessageNotWritableException; import java.io.IOException; import javax.xml.transform.Result; import javax.xml.transform.Source; import org.springframework.beans.TypeMismatchException; import org.springframework.oxm.Marshaller; import org.springframework.oxm.MarshallingFailureException; import org.springframework.oxm.Unmarshaller; import org.springframework.oxm.UnmarshallingFailureException; import org.springframework.util.Assert; /** * Implementation of {@link jails.http.converter.HttpMessageConverter HttpMessageConverter} that can read * and write XML using Spring's {@link Marshaller} and {@link Unmarshaller} abstractions. * * <p>This converter requires a {@code Marshaller} and {@code Unmarshaller} before it can be used. These can be injected * by the {@linkplain #MarshallingHttpMessageConverter(Marshaller) constructor} or {@linkplain * #setMarshaller(Marshaller) bean properties}. * * <p>By default, this converter supports {@code text/xml} and {@code application/xml}. This can be overridden by * setting the {@link #setSupportedMediaTypes(java.util.List) supportedMediaTypes} property. * * @author Arjen Poutsma * @since 3.0 */ public class MarshallingHttpMessageConverter extends AbstractXmlHttpMessageConverter<Object> { private Marshaller marshaller; private Unmarshaller unmarshaller; /** * Construct a new {@code MarshallingHttpMessageConverter} with no {@link Marshaller} or {@link Unmarshaller} set. The * marshaller and unmarshaller must be set after construction by invoking {@link #setMarshaller(Marshaller)} and {@link * #setUnmarshaller(Unmarshaller)} . */ public MarshallingHttpMessageConverter() { } /** * Construct a new {@code MarshallingMessageConverter} with the given {@link Marshaller} set. <p>If the given {@link * Marshaller} also implements the {@link Unmarshaller} interface, it is used for both marshalling and unmarshalling. * Otherwise, an exception is thrown. <p>Note that all {@code Marshaller} implementations in Spring also implement the * {@code Unmarshaller} interface, so that you can safely use this constructor. * @param marshaller object used as marshaller and unmarshaller */ public MarshallingHttpMessageConverter(Marshaller marshaller) { Assert.notNull(marshaller, "marshaller must not be null"); this.marshaller = marshaller; if (marshaller instanceof Unmarshaller) { this.unmarshaller = (Unmarshaller) marshaller; } } /** * Construct a new <code>MarshallingMessageConverter</code> with the given {@code Marshaller} and {@code * Unmarshaller}. * @param marshaller the Marshaller to use * @param unmarshaller the Unmarshaller to use */ public MarshallingHttpMessageConverter(Marshaller marshaller, Unmarshaller unmarshaller) { Assert.notNull(marshaller, "marshaller must not be null"); Assert.notNull(unmarshaller, "unmarshaller must not be null"); this.marshaller = marshaller; this.unmarshaller = unmarshaller; } /** * Set the {@link Marshaller} to be used by this message converter. */ public void setMarshaller(Marshaller marshaller) { this.marshaller = marshaller; } /** * Set the {@link Unmarshaller} to be used by this message converter. */ public void setUnmarshaller(Unmarshaller unmarshaller) { this.unmarshaller = unmarshaller; } @Override public boolean supports(Class<?> clazz) { return this.unmarshaller.supports(clazz); } @Override protected Object readFromSource(Class<?> clazz, HttpHeaders headers, Source source) throws IOException { Assert.notNull(this.unmarshaller, "Property 'unmarshaller' is required"); try { Object result = this.unmarshaller.unmarshal(source); if (!clazz.isInstance(result)) { throw new TypeMismatchException(result, clazz); } return result; } catch (UnmarshallingFailureException ex) { throw new HttpMessageNotReadableException("Could not read [" + clazz + "]", ex); } } @Override protected void writeToResult(Object o, HttpHeaders headers, Result result) throws IOException { Assert.notNull(this.marshaller, "Property 'marshaller' is required"); try { this.marshaller.marshal(o, result); } catch (MarshallingFailureException ex) { throw new HttpMessageNotWritableException("Could not write [" + o + "]", ex); } } }