/*
* Copyright 2005-2014 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.ws.server.endpoint;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import javax.xml.namespace.NamespaceContext;
import javax.xml.stream.XMLEventFactory;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLEventWriter;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.events.XMLEvent;
import javax.xml.stream.util.XMLEventConsumer;
import javax.xml.transform.Result;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.stream.StreamSource;
import org.springframework.util.xml.StaxUtils;
import org.springframework.ws.WebServiceMessage;
import org.springframework.ws.context.MessageContext;
/**
* Abstract base class for endpoints that handle the message payload with event-based StAX. Allows subclasses to read
* the request with a {@code XMLEventReader}, and to create a response using a {@code XMLEventWriter}.
*
* @author Arjen Poutsma
* @see #invokeInternal(javax.xml.stream.XMLEventReader,javax.xml.stream.util.XMLEventConsumer,
* javax.xml.stream.XMLEventFactory)
* @see XMLEventReader
* @see XMLEventWriter
* @since 1.0.0
* @deprecated as of Spring Web Services 2.0, in favor of annotated endpoints
*/
@Deprecated
public abstract class AbstractStaxEventPayloadEndpoint extends AbstractStaxPayloadEndpoint implements MessageEndpoint {
private XMLEventFactory eventFactory;
@Override
public final void invoke(MessageContext messageContext) throws Exception {
XMLEventReader eventReader = getEventReader(messageContext.getRequest().getPayloadSource());
XMLEventWriter streamWriter = new ResponseCreatingEventWriter(messageContext);
invokeInternal(eventReader, streamWriter, getEventFactory());
streamWriter.flush();
}
/**
* Create a {@code XMLEventFactory} that this endpoint will use to create {@code XMLEvent}s. Can be
* overridden in subclasses, adding further initialization of the factory. The resulting
* {@code XMLEventFactory} is cached, so this method will only be called once.
*
* @return the created {@code XMLEventFactory}
*/
protected XMLEventFactory createXmlEventFactory() {
return XMLEventFactory.newInstance();
}
/** Returns an {@code XMLEventFactory} to read XML from. */
private XMLEventFactory getEventFactory() {
if (eventFactory == null) {
eventFactory = createXmlEventFactory();
}
return eventFactory;
}
private XMLEventReader getEventReader(Source source) throws XMLStreamException, TransformerException {
if (source == null) {
return null;
}
XMLEventReader eventReader = null;
if (StaxUtils.isStaxSource(source)) {
eventReader = StaxUtils.getXMLEventReader(source);
if (eventReader == null) {
XMLStreamReader streamReader = StaxUtils.getXMLStreamReader(source);
if (streamReader != null) {
try {
eventReader = getInputFactory().createXMLEventReader(streamReader);
}
catch (XMLStreamException ex) {
eventReader = null;
}
}
}
}
if (eventReader == null) {
try {
eventReader = getInputFactory().createXMLEventReader(source);
}
catch (XMLStreamException ex) {
eventReader = null;
}
catch (UnsupportedOperationException ex) {
eventReader = null;
}
}
if (eventReader == null) {
// as a final resort, transform the source to a stream, and read from that
ByteArrayOutputStream os = new ByteArrayOutputStream();
transform(source, new StreamResult(os));
ByteArrayInputStream is = new ByteArrayInputStream(os.toByteArray());
eventReader = getInputFactory().createXMLEventReader(is);
}
return eventReader;
}
private XMLEventWriter getEventWriter(Result result) {
XMLEventWriter eventWriter = null;
if (StaxUtils.isStaxResult(result)) {
eventWriter = StaxUtils.getXMLEventWriter(result);
}
if (eventWriter == null) {
try {
eventWriter = getOutputFactory().createXMLEventWriter(result);
}
catch (XMLStreamException ex) {
// ignore
}
}
return eventWriter;
}
/**
* Template method. Subclasses must implement this. Offers the request payload as a {@code XMLEventReader}, and
* a {@code XMLEventWriter} to write the response payload to.
*
* @param eventReader the reader to read the payload events from
* @param eventWriter the writer to write payload events to
* @param eventFactory an {@code XMLEventFactory} that can be used to create events
*/
protected abstract void invokeInternal(XMLEventReader eventReader,
XMLEventConsumer eventWriter,
XMLEventFactory eventFactory) throws Exception;
/**
* Implementation of the {@code XMLEventWriter} interface that creates a response
* {@code WebServiceMessage} as soon as any method is called, thus lazily creating the response.
*/
private class ResponseCreatingEventWriter implements XMLEventWriter {
private XMLEventWriter eventWriter;
private MessageContext messageContext;
private ByteArrayOutputStream os;
public ResponseCreatingEventWriter(MessageContext messageContext) {
this.messageContext = messageContext;
}
@Override
public NamespaceContext getNamespaceContext() {
return eventWriter.getNamespaceContext();
}
@Override
public void setNamespaceContext(NamespaceContext context) throws XMLStreamException {
createEventWriter();
eventWriter.setNamespaceContext(context);
}
@Override
public void add(XMLEventReader reader) throws XMLStreamException {
createEventWriter();
while (reader.hasNext()) {
add(reader.nextEvent());
}
}
@Override
public void add(XMLEvent event) throws XMLStreamException {
createEventWriter();
eventWriter.add(event);
if (event.isEndDocument()) {
if (os != null) {
eventWriter.flush();
// if we used an output stream cache, we have to transform it to the response again
try {
ByteArrayInputStream is = new ByteArrayInputStream(os.toByteArray());
transform(new StreamSource(is), messageContext.getResponse().getPayloadResult());
}
catch (TransformerException ex) {
throw new XMLStreamException(ex);
}
}
}
}
@Override
public void close() throws XMLStreamException {
if (eventWriter != null) {
eventWriter.close();
}
}
@Override
public void flush() throws XMLStreamException {
if (eventWriter != null) {
eventWriter.flush();
}
}
@Override
public String getPrefix(String uri) throws XMLStreamException {
createEventWriter();
return eventWriter.getPrefix(uri);
}
@Override
public void setDefaultNamespace(String uri) throws XMLStreamException {
createEventWriter();
eventWriter.setDefaultNamespace(uri);
}
@Override
public void setPrefix(String prefix, String uri) throws XMLStreamException {
createEventWriter();
eventWriter.setPrefix(prefix, uri);
}
private void createEventWriter() throws XMLStreamException {
if (eventWriter == null) {
WebServiceMessage response = messageContext.getResponse();
eventWriter = getEventWriter(response.getPayloadResult());
if (eventWriter == null) {
// as a final resort, use a stream, and transform that at endDocument()
os = new ByteArrayOutputStream();
eventWriter = getOutputFactory().createXMLEventWriter(os);
}
}
}
}
}