/*
* JBoss, Home of Professional Open Source
* Copyright 2006, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags.
* See the copyright.txt in the distribution for a full listing
* of individual contributors.
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License, v. 2.0.
* This program is distributed in the hope that it will be useful, but WITHOUT A
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU General Public License for more details.
* You should have received a copy of the GNU General Public License,
* v. 2.0 along with this distribution; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*
* (C) 2005-2006,
* @author JBoss Inc.
*/
package org.jboss.internal.soa.esb.util.stax;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.xml.namespace.NamespaceContext;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;
/**
* Helper class for Stream operations.
* @author kevin
*/
public class StreamHelper
{
/**
* Pseudo namespace used to unbind a prefix.
*/
private static final String UNBOUND_NAMESPACE = "http://www.jboss.com/stax/parsing/unboundnamespace" ;
/**
* Write a start element with appropriate namespace declarations if necessary
* @param out The output stream.
* @param elementName The element name.
* @return The previous namespace if written, null otherwise.
* @throws XMLStreamException for errors during writing.
*/
public static String writeStartElement(final XMLStreamWriter out, final QName elementName)
throws XMLStreamException
{
final String namespaceURI = QNameHelper.getNormalisedValue(elementName.getNamespaceURI()) ;
final String localName = elementName.getLocalPart() ;
final NamespaceContext namespaceContext = out.getNamespaceContext() ;
final boolean writeNamespace = (namespaceContext.getPrefix(namespaceURI) == null) ;
if (writeNamespace)
{
final String prefix = QNameHelper.getNormalisedValue(elementName.getPrefix()) ;
final String origNamespace = QNameHelper.getNormalisedValue(namespaceContext.getNamespaceURI(prefix)) ;
if (prefix.length() == 0)
{
out.setDefaultNamespace(namespaceURI) ;
out.writeStartElement(namespaceURI, localName) ;
out.writeDefaultNamespace(namespaceURI) ;
}
else
{
out.setPrefix(prefix, namespaceURI) ;
out.writeStartElement(namespaceURI, localName) ;
out.writeNamespace(prefix, namespaceURI) ;
}
return origNamespace ;
}
else
{
out.writeStartElement(namespaceURI, localName) ;
return null ;
}
}
/**
* Write an end element removing the namespace binding if necessary
* @param out The output stream.
* @param prefix The element prefix.
* @param namespaceURI The previous binding for the prefix.
* @throws XMLStreamException for errors during writing.
*/
public static void writeEndElement(final XMLStreamWriter out, final String prefix,
final String namespaceURI)
throws XMLStreamException
{
out.writeEndElement() ;
if (namespaceURI != null)
{
final String resetNamespace = (namespaceURI.length() == 0 ? UNBOUND_NAMESPACE : namespaceURI) ;
if (prefix.length() == 0)
{
out.setDefaultNamespace(resetNamespace) ;
}
else
{
out.setPrefix(prefix, resetNamespace) ;
}
}
}
/**
* Write the element to the stream.
* @param out The output stream.
* @param elementName The name of the element.
* @param elementContent The element contents.
* @throws XMLStreamException Thrown for errors during writing.
*/
public static void writeElement(final XMLStreamWriter out, final QName elementName,
final ElementContent elementContent)
throws XMLStreamException
{
final String origNamespace = writeStartElement(out, elementName) ;
elementContent.writeContent(out) ;
writeEndElement(out, elementName.getPrefix(), origNamespace) ;
}
/**
* Write the attributes to the stream.
* @param out The output stream.
* @param attributes The attributes.
* @throws XMLStreamException Thrown for errors during writing.
*/
public static void writeAttributes(final XMLStreamWriter out, final Map<QName, Object> attributes)
throws XMLStreamException
{
final Set<Map.Entry<QName, Object>> entrySet = attributes.entrySet() ;
final Iterator<Map.Entry<QName, Object>> entryIter = entrySet.iterator() ;
while(entryIter.hasNext())
{
final Map.Entry<QName, Object> entry = entryIter.next() ;
final QName name = (QName)entry.getKey() ;
final Object value = entry.getValue() ;
writeAttribute(out, name, value) ;
}
}
/**
* Write the attribute to the stream.
* @param out The output stream.
* @param attributeName The attribute name.
* @param attributeValue The attribute value.
* @throws XMLStreamException Thrown for errors during writing.
*/
public static void writeAttribute(final XMLStreamWriter out, final QName attributeName,
final Object attributeValue)
throws XMLStreamException
{
if (attributeValue instanceof QName)
{
writeAttribute(out, attributeName, (QName)attributeValue) ;
}
else
{
writeAttribute(out, attributeName, attributeValue.toString()) ;
}
}
/**
* Write the attribute to the stream.
* @param out The output stream.
* @param attributeName The attribute name.
* @param attributeValue The attribute value as a QName.
* @throws XMLStreamException Thrown for errors during writing.
*/
public static void writeAttribute(final XMLStreamWriter out, final QName attributeName,
final QName attributeValue)
throws XMLStreamException
{
final String namespaceURI = QNameHelper.getNormalisedValue(attributeValue.getNamespaceURI()) ;
if (namespaceURI.length() == 0)
{
writeAttribute(out, attributeName, attributeValue.getLocalPart()) ;
}
else
{
final NamespaceContext namespaceContext = out.getNamespaceContext() ;
final String origPrefix = namespaceContext.getPrefix(namespaceURI) ;
if (origPrefix == null)
{
final String prefix = QNameHelper.getNormalisedValue(attributeValue.getPrefix()) ;
writeNamespace(out, prefix, namespaceURI) ;
writeAttribute(out, attributeName, QNameHelper.toQualifiedName(attributeValue)) ;
}
else
{
writeAttribute(out, attributeName, QNameHelper.toQualifiedName(origPrefix, attributeValue.getLocalPart())) ;
}
}
}
/**
* Write the attribute to the stream.
* @param out The output stream.
* @param attributeName The attribute name.
* @param attributeValue The attribute value.
* @throws XMLStreamException Thrown for errors during writing.
*/
public static void writeAttribute(final XMLStreamWriter out, final QName attributeName,
final String attributeValue)
throws XMLStreamException
{
final String namespaceURI = QNameHelper.getNormalisedValue(attributeName.getNamespaceURI()) ;
final String localName = attributeName.getLocalPart() ;
if (namespaceURI.length() == 0)
{
out.writeAttribute(localName, attributeValue) ;
}
else
{
final String prefix = QNameHelper.getNormalisedValue(attributeName.getPrefix()) ;
writeNamespace(out, prefix, namespaceURI) ;
out.writeAttribute(namespaceURI, localName, attributeValue) ;
}
}
/**
* Write the QName to the stream as text.
* @param out The output stream.
* @param qName The qualified name.
* @throws XMLStreamException Thrown for errors during writing.
*/
public static void writeQualifiedName(final XMLStreamWriter out, final QName qName)
throws XMLStreamException
{
final String namespaceURI = QNameHelper.getNormalisedValue(qName.getNamespaceURI()) ;
if (namespaceURI.length() == 0)
{
out.writeCharacters(QNameHelper.toQualifiedName(qName)) ;
}
else
{
final NamespaceContext namespaceContext = out.getNamespaceContext() ;
final String origPrefix = namespaceContext.getPrefix(namespaceURI) ;
if (origPrefix == null)
{
final String prefix = QNameHelper.getNormalisedValue(qName.getPrefix()) ;
writeNamespace(out, prefix, namespaceURI) ;
out.writeCharacters(QNameHelper.toQualifiedName(qName)) ;
}
else
{
out.writeCharacters(QNameHelper.toQualifiedName(origPrefix, qName.getLocalPart())) ;
}
}
}
/**
* Write the namespace if necessary.
* @param out The output stream.
* @param prefix The namespace prefix.
* @param namespaceURI The namespaceURI.
* @throws XMLStreamException Thrown for errors during writing.
*/
public static void writeNamespace(final XMLStreamWriter out, final String prefix, final String namespaceURI)
throws XMLStreamException
{
final NamespaceContext namespaceContext = out.getNamespaceContext() ;
final boolean writeNamespace = (namespaceContext.getPrefix(namespaceURI) == null) ;
if (writeNamespace)
{
out.setPrefix(prefix, namespaceURI) ;
out.writeNamespace(prefix, namespaceURI) ;
}
}
/**
* Make sure the stream is at the start of the next element.
* @param streamReader The current stream reader.
* @throws XMLStreamException For parsing errors.
*/
public static void skipToNextStartElement(final XMLStreamReader streamReader)
throws XMLStreamException
{
if (streamReader.hasNext())
{
streamReader.nextTag() ;
if (streamReader.isEndElement())
{
throw new XMLStreamException("Unexpected end element: " + streamReader.getName()) ;
}
}
else
{
throw new XMLStreamException("Unexpected end of document reached") ;
}
}
/**
* Make sure the stream is at the start of an element.
* @param streamReader The current stream reader.
* @throws XMLStreamException For parsing errors.
*/
public static void skipToStartElement(final XMLStreamReader streamReader)
throws XMLStreamException
{
while (!streamReader.isStartElement())
{
if (streamReader.hasNext())
{
streamReader.next() ;
}
else
{
throw new XMLStreamException("Unexpected end of document reached") ;
}
}
}
/**
* Check the next start tag is as expected.
* @param streamReader The stream reader.
* @param expected The expected qualified name.
* @throws XMLStreamException For errors during parsing.
*/
public static void checkNextStartTag(final XMLStreamReader streamReader, final QName expected)
throws XMLStreamException
{
skipToNextStartElement(streamReader) ;
checkTag(streamReader, expected) ;
}
/**
* Check the end tag is as expected.
* @param streamReader The stream reader.
* @param expected The expected qualified name.
* @throws XMLStreamException For errors during parsing.
*/
public static void checkEndTag(final XMLStreamReader streamReader, final QName expected)
throws XMLStreamException
{
streamReader.require(XMLStreamConstants.END_ELEMENT,
expected.getNamespaceURI(), expected.getLocalPart()) ;
}
/**
* Compare the element tag with the expected qualified name.
* @param streamReader The current stream reader.
* @param expected The expected qualified name.
* @throws XMLStreamException For errors during parsing.
*/
public static void checkTag(final XMLStreamReader streamReader, final QName expected)
throws XMLStreamException
{
final QName elementName = streamReader.getName() ;
if (!expected.equals(elementName))
{
throw new XMLStreamException("Unexpected start element: " + elementName) ;
}
}
/**
* Check to see if the parent element is finished.
* @param streamReader The stream reader.
* @return true if it is finished, false otherwise.
* @throws XMLStreamException For errors during parsing.
*/
public static boolean checkParentFinished(final XMLStreamReader streamReader)
throws XMLStreamException
{
return (streamReader.nextTag() == XMLStreamConstants.END_ELEMENT) ;
}
/**
* Get the value of the specified attribute.
* @param streamReader The current XML stream reader.
* @param name The name of the attribute.
* @return The value of the attribute.
*/
public static String getAttributeValue(final XMLStreamReader streamReader, final QName name)
{
return streamReader.getAttributeValue(name.getNamespaceURI(), name.getLocalPart()) ;
}
}