/*
* 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.support;
import java.io.InputStream;
import java.io.Reader;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.events.XMLEvent;
import javax.xml.transform.Source;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMResult;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;
import org.springframework.xml.namespace.QNameUtils;
import org.springframework.xml.transform.TransformerHelper;
import org.springframework.xml.transform.TraxUtils;
/**
* Helper class for determining the root qualified name of a Web Service payload.
*
* @author Arjen Poutsma
* @since 1.0.0
*/
public abstract class PayloadRootUtils {
private PayloadRootUtils() {
}
/**
* Returns the root qualified name of the given source, transforming it if necessary.
*
* @param source the source to get the root element from
* @param transformerFactory a transformer factory, necessary if the given source is not a {@code DOMSource}
* @return the root element, or {@code null} if {@code source} is {@code null}
*/
public static QName getPayloadRootQName(Source source, TransformerFactory transformerFactory)
throws TransformerException {
return getPayloadRootQName(source, new TransformerHelper(transformerFactory));
}
public static QName getPayloadRootQName(Source source, TransformerHelper transformerHelper)
throws TransformerException {
if (source == null) {
return null;
}
try {
PayloadRootSourceCallback callback = new PayloadRootSourceCallback();
TraxUtils.doWithSource(source, callback);
if (callback.result != null) {
return callback.result;
}
else {
// we have no other option than to transform
DOMResult domResult = new DOMResult();
transformerHelper.transform(source, domResult);
Document document = (Document) domResult.getNode();
return QNameUtils.getQNameForNode(document.getDocumentElement());
}
}
catch (TransformerException ex) {
throw ex;
}
catch (Exception ex) {
return null;
}
}
private static class PayloadRootSourceCallback implements TraxUtils.SourceCallback {
private QName result;
@Override
public void domSource(Node node) throws Exception {
if (node.getNodeType() == Node.ELEMENT_NODE) {
result = QNameUtils.getQNameForNode(node);
}
else if (node.getNodeType() == Node.DOCUMENT_NODE) {
Document document = (Document) node;
result = QNameUtils.getQNameForNode(document.getDocumentElement());
}
}
@Override
public void staxSource(XMLEventReader eventReader) throws Exception {
XMLEvent event = eventReader.peek();
if (event != null && event.isStartDocument()) {
event = eventReader.nextTag();
}
if (event != null) {
if (event.isStartElement()) {
result = event.asStartElement().getName();
}
else if (event.isEndElement()) {
result = event.asEndElement().getName();
}
}
}
@Override
public void staxSource(XMLStreamReader streamReader) throws Exception {
if (streamReader.getEventType() == XMLStreamConstants.START_DOCUMENT) {
try {
streamReader.nextTag();
}
catch (XMLStreamException ex) {
throw new IllegalStateException("Could not read next tag: " + ex.getMessage(), ex);
}
}
if (streamReader.getEventType() == XMLStreamConstants.START_ELEMENT ||
streamReader.getEventType() == XMLStreamConstants.END_ELEMENT) {
result = streamReader.getName();
}
}
@Override
public void saxSource(XMLReader reader, InputSource inputSource) throws Exception {
// Do nothing
}
@Override
public void streamSource(InputStream inputStream) throws Exception {
// Do nothing
}
@Override
public void streamSource(Reader reader) throws Exception {
// Do nothing
}
@Override
public void source(String systemId) throws Exception {
// Do nothing
}
}
}