/*
* 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 org.springframework.util.xml;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
/**
* Abstract base class for SAX <code>ContentHandler</code> implementations that use StAX as a basis. All methods
* delegate to internal template methods, capable of throwing a <code>XMLStreamException</code>. Additionally, an
* namespace context is used to keep track of declared namespaces.
*
* @author Arjen Poutsma
* @since 3.0
*/
abstract class AbstractStaxContentHandler implements ContentHandler {
private SimpleNamespaceContext namespaceContext = new SimpleNamespaceContext();
private boolean namespaceContextChanged = false;
public final void startDocument() throws SAXException {
namespaceContext.clear();
namespaceContextChanged = false;
try {
startDocumentInternal();
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle startDocument: " + ex.getMessage(), ex);
}
}
protected abstract void startDocumentInternal() throws XMLStreamException;
public final void endDocument() throws SAXException {
namespaceContext.clear();
namespaceContextChanged = false;
try {
endDocumentInternal();
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle startDocument: " + ex.getMessage(), ex);
}
}
protected abstract void endDocumentInternal() throws XMLStreamException;
/**
* Binds the given prefix to the given namespaces.
*
* @see SimpleNamespaceContext#bindNamespaceUri(String,String)
*/
public final void startPrefixMapping(String prefix, String uri) {
namespaceContext.bindNamespaceUri(prefix, uri);
namespaceContextChanged = true;
}
/**
* Removes the binding for the given prefix.
*
* @see SimpleNamespaceContext#removeBinding(String)
*/
public final void endPrefixMapping(String prefix) {
namespaceContext.removeBinding(prefix);
namespaceContextChanged = true;
}
public final void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
try {
startElementInternal(toQName(uri, qName), atts, namespaceContextChanged ? namespaceContext : null);
namespaceContextChanged = false;
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle startElement: " + ex.getMessage(), ex);
}
}
protected abstract void startElementInternal(QName name, Attributes atts, SimpleNamespaceContext namespaceContext)
throws XMLStreamException;
public final void endElement(String uri, String localName, String qName) throws SAXException {
try {
endElementInternal(toQName(uri, qName), namespaceContextChanged ? namespaceContext : null);
namespaceContextChanged = false;
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle endElement: " + ex.getMessage(), ex);
}
}
protected abstract void endElementInternal(QName name, SimpleNamespaceContext namespaceContext)
throws XMLStreamException;
public final void characters(char ch[], int start, int length) throws SAXException {
try {
charactersInternal(ch, start, length);
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle characters: " + ex.getMessage(), ex);
}
}
protected abstract void charactersInternal(char[] ch, int start, int length) throws XMLStreamException;
public final void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
try {
ignorableWhitespaceInternal(ch, start, length);
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle ignorableWhitespace:" + ex.getMessage(), ex);
}
}
protected abstract void ignorableWhitespaceInternal(char[] ch, int start, int length) throws XMLStreamException;
public final void processingInstruction(String target, String data) throws SAXException {
try {
processingInstructionInternal(target, data);
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle processingInstruction: " + ex.getMessage(), ex);
}
}
protected abstract void processingInstructionInternal(String target, String data) throws XMLStreamException;
public final void skippedEntity(String name) throws SAXException {
try {
skippedEntityInternal(name);
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle skippedEntity: " + ex.getMessage(), ex);
}
}
/**
* Convert a namespace URI and DOM or SAX qualified name to a <code>QName</code>. The qualified name can have the form
* <code>prefix:localname</code> or <code>localName</code>.
*
* @param namespaceUri the namespace URI
* @param qualifiedName the qualified name
* @return a QName
*/
protected QName toQName(String namespaceUri, String qualifiedName) {
int idx = qualifiedName.indexOf(':');
if (idx == -1) {
return new QName(namespaceUri, qualifiedName);
}
else {
String prefix = qualifiedName.substring(0, idx);
String localPart = qualifiedName.substring(idx + 1);
return new QName(namespaceUri, localPart, prefix);
}
}
protected abstract void skippedEntityInternal(String name) throws XMLStreamException;
}
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