/*
* Copyright 2002-2017 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 java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.xml.XMLConstants;
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;
import org.xml.sax.ext.LexicalHandler;
/**
* Abstract base class for SAX {@code ContentHandler} and {@code LexicalHandler}
* implementations that use StAX as a basis. All methods delegate to internal template
* methods, capable of throwing a {@code XMLStreamException}. Additionally, an namespace
* context stack is used to keep track of declared namespaces.
*
* @author Arjen Poutsma
* @since 4.0.3
*/
abstract class AbstractStaxHandler implements ContentHandler, LexicalHandler {
private final List<Map<String, String>> namespaceMappings = new ArrayList<>();
private boolean inCData;
@Override
public final void startDocument() throws SAXException {
removeAllNamespaceMappings();
newNamespaceMapping();
try {
startDocumentInternal();
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle startDocument: " + ex.getMessage(), ex);
}
}
@Override
public final void endDocument() throws SAXException {
removeAllNamespaceMappings();
try {
endDocumentInternal();
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle endDocument: " + ex.getMessage(), ex);
}
}
@Override
public final void startPrefixMapping(String prefix, String uri) {
currentNamespaceMapping().put(prefix, uri);
}
@Override
public final void endPrefixMapping(String prefix) {
}
@Override
public final void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
try {
startElementInternal(toQName(uri, qName), atts, currentNamespaceMapping());
newNamespaceMapping();
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle startElement: " + ex.getMessage(), ex);
}
}
@Override
public final void endElement(String uri, String localName, String qName) throws SAXException {
try {
endElementInternal(toQName(uri, qName), currentNamespaceMapping());
removeNamespaceMapping();
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle endElement: " + ex.getMessage(), ex);
}
}
@Override
public final void characters(char ch[], int start, int length) throws SAXException {
try {
String data = new String(ch, start, length);
if (!this.inCData) {
charactersInternal(data);
}
else {
cDataInternal(data);
}
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle characters: " + ex.getMessage(), ex);
}
}
@Override
public final void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
try {
ignorableWhitespaceInternal(new String(ch, start, length));
}
catch (XMLStreamException ex) {
throw new SAXException(
"Could not handle ignorableWhitespace:" + ex.getMessage(), ex);
}
}
@Override
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);
}
}
@Override
public final void skippedEntity(String name) throws SAXException {
try {
skippedEntityInternal(name);
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle skippedEntity: " + ex.getMessage(), ex);
}
}
@Override
public final void startDTD(String name, String publicId, String systemId) throws SAXException {
try {
StringBuilder builder = new StringBuilder("<!DOCTYPE ");
builder.append(name);
if (publicId != null) {
builder.append(" PUBLIC \"");
builder.append(publicId);
builder.append("\" \"");
}
else {
builder.append(" SYSTEM \"");
}
builder.append(systemId);
builder.append("\">");
dtdInternal(builder.toString());
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle startDTD: " + ex.getMessage(), ex);
}
}
@Override
public final void endDTD() throws SAXException {
}
@Override
public final void startCDATA() throws SAXException {
this.inCData = true;
}
@Override
public final void endCDATA() throws SAXException {
this.inCData = false;
}
@Override
public final void comment(char[] ch, int start, int length) throws SAXException {
try {
commentInternal(new String(ch, start, length));
}
catch (XMLStreamException ex) {
throw new SAXException("Could not handle comment: " + ex.getMessage(), ex);
}
}
@Override
public void startEntity(String name) throws SAXException {
}
@Override
public void endEntity(String name) throws SAXException {
}
/**
* Convert a namespace URI and DOM or SAX qualified name to a {@code QName}. The
* qualified name can have the form {@code prefix:localname} or {@code localName}.
* @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 boolean isNamespaceDeclaration(QName qName) {
String prefix = qName.getPrefix();
String localPart = qName.getLocalPart();
return (XMLConstants.XMLNS_ATTRIBUTE.equals(localPart) && prefix.isEmpty()) ||
(XMLConstants.XMLNS_ATTRIBUTE.equals(prefix) && !localPart.isEmpty());
}
private Map<String, String> currentNamespaceMapping() {
return this.namespaceMappings.get(this.namespaceMappings.size() - 1);
}
private void newNamespaceMapping() {
this.namespaceMappings.add(new HashMap<>());
}
private void removeNamespaceMapping() {
this.namespaceMappings.remove(this.namespaceMappings.size() - 1);
}
private void removeAllNamespaceMappings() {
this.namespaceMappings.clear();
}
protected abstract void startDocumentInternal() throws XMLStreamException;
protected abstract void endDocumentInternal() throws XMLStreamException;
protected abstract void startElementInternal(QName name, Attributes attributes,
Map<String, String> namespaceMapping) throws XMLStreamException;
protected abstract void endElementInternal(QName name, Map<String, String> namespaceMapping)
throws XMLStreamException;
protected abstract void charactersInternal(String data) throws XMLStreamException;
protected abstract void cDataInternal(String data) throws XMLStreamException;
protected abstract void ignorableWhitespaceInternal(String data) throws XMLStreamException;
protected abstract void processingInstructionInternal(String target, String data)
throws XMLStreamException;
protected abstract void skippedEntityInternal(String name) throws XMLStreamException;
protected abstract void dtdInternal(String dtd) throws XMLStreamException;
protected abstract void commentInternal(String comment) throws XMLStreamException;
}