/*
* Copyright (c) 2002-2010 Gargoyle Software Inc.
*
* 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 com.gargoylesoftware.htmlunit.xml;
import java.io.IOException;
import java.io.StringReader;
import java.util.HashMap;
import java.util.Map;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentType;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.Attributes;
import org.xml.sax.EntityResolver;
import org.xml.sax.ErrorHandler;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.SAXParseException;
import org.xml.sax.helpers.AttributesImpl;
import com.gargoylesoftware.htmlunit.SgmlPage;
import com.gargoylesoftware.htmlunit.WebResponse;
import com.gargoylesoftware.htmlunit.html.DomAttr;
import com.gargoylesoftware.htmlunit.html.DomCDataSection;
import com.gargoylesoftware.htmlunit.html.DomComment;
import com.gargoylesoftware.htmlunit.html.DomDocumentType;
import com.gargoylesoftware.htmlunit.html.DomElement;
import com.gargoylesoftware.htmlunit.html.DomNode;
import com.gargoylesoftware.htmlunit.html.DomProcessingInstruction;
import com.gargoylesoftware.htmlunit.html.DomText;
import com.gargoylesoftware.htmlunit.html.HTMLParser;
import com.gargoylesoftware.htmlunit.html.HtmlPage;
import com.gargoylesoftware.htmlunit.html.IElementFactory;
/**
* <span style="color:red">INTERNAL API - SUBJECT TO CHANGE AT ANY TIME - USE AT YOUR OWN RISK.</span><br/>
*
* Provides facility method to work with XML responses.
*
* @version $Revision: 5301 $
* @author Marc Guillemot
* @author Ahmed Ashour
* @author Sudhan Moghe
*/
public final class XmlUtil {
private static final Log LOG = LogFactory.getLog(XmlUtil.class);
private static final ErrorHandler DISCARD_MESSAGES_HANDLER = new ErrorHandler() {
/**
* Does nothing as we're not interested in this.
*/
public void error(final SAXParseException exception) {
// Does nothing as we're not interested in this.
}
/**
* Does nothing as we're not interested in this.
*/
public void fatalError(final SAXParseException exception) {
// Does nothing as we're not interested in this.
}
/**
* Does nothing as we're not interested in this.
*/
public void warning(final SAXParseException exception) {
// Does nothing as we're not interested in this.
}
};
/**
* Utility class, hide constructor.
*/
private XmlUtil() {
// Empty.
}
/**
* Builds a document from the content of the web response.
* A warning is logged if an exception is thrown while parsing the XML content
* (for instance when the content is not a valid XML and can't be parsed).
*
* @param webResponse the response from the server
* @throws IOException if the page could not be created
* @return the parse result
* @throws SAXException if the parsing fails
* @throws ParserConfigurationException if a DocumentBuilder cannot be created
*/
public static Document buildDocument(final WebResponse webResponse)
throws IOException, SAXException, ParserConfigurationException {
final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
final InputSource source = new InputSource(new StringReader(webResponse.getContentAsString()));
final DocumentBuilder builder = factory.newDocumentBuilder();
builder.setErrorHandler(DISCARD_MESSAGES_HANDLER);
builder.setEntityResolver(new EntityResolver() {
public InputSource resolveEntity(final String publicId, final String systemId)
throws SAXException, IOException {
return new InputSource(new StringReader(""));
}
});
return builder.parse(source);
}
/**
* Recursively appends a {@link Node} child to {@link DomNode} parent.
*
* @param page the owner page of {@link DomElement}s to be created
* @param parent the parent DomNode
* @param child the child Node
*/
public static void appendChild(final SgmlPage page, final DomNode parent, final Node child) {
final DocumentType documentType = child.getOwnerDocument().getDoctype();
if (documentType != null && page instanceof XmlPage) {
final DomDocumentType domDoctype = new DomDocumentType(
page, documentType.getName(), documentType.getPublicId(), documentType.getSystemId());
((XmlPage) page).setDocumentType(domDoctype);
}
final DomNode childXml = createFrom(page, child);
parent.appendChild(childXml);
copy(page, child, childXml);
}
private static DomNode createFrom(final SgmlPage page, final Node source) {
if (source.getNodeType() == Node.TEXT_NODE) {
return new DomText(page, source.getNodeValue());
}
final String ns = source.getNamespaceURI();
String localName = source.getLocalName();
if (HTMLParser.XHTML_NAMESPACE.equals(ns)) {
final IElementFactory factory = HTMLParser.getFactory(localName);
return factory.createElementNS(page, ns, localName, namedNodeMapToSaxAttributes(source.getAttributes()));
}
final Map<String, DomAttr> attributes = new HashMap<String, DomAttr>();
final NamedNodeMap nodeAttributes = source.getAttributes();
for (int i = 0; i < nodeAttributes.getLength(); i++) {
final Attr attribute = (Attr) nodeAttributes.item(i);
final String namespaceURI = attribute.getNamespaceURI();
final String qualifiedName;
if (attribute.getPrefix() != null) {
qualifiedName = attribute.getPrefix() + ':' + attribute.getLocalName();
}
else {
qualifiedName = attribute.getLocalName();
}
final String value = attribute.getNodeValue();
final boolean specified = attribute.getSpecified();
final DomAttr xmlAttribute = new DomAttr(page, namespaceURI, qualifiedName, value, specified);
attributes.put(attribute.getNodeName(), xmlAttribute);
}
if (page instanceof HtmlPage) {
localName = localName.toUpperCase();
}
final String qualifiedName;
if (source.getPrefix() == null) {
qualifiedName = localName;
}
else {
qualifiedName = source.getPrefix() + ':' + localName;
}
return new DomElement(source.getNamespaceURI(), qualifiedName, page, attributes);
}
private static Attributes namedNodeMapToSaxAttributes(final NamedNodeMap attributesMap) {
final AttributesImpl attributes = new AttributesImpl();
final int length = attributesMap.getLength();
for (int i = 0; i < length; ++i) {
final Node attr = attributesMap.item(i);
attributes.addAttribute(attr.getNamespaceURI(), attr.getLocalName(),
attr.getNodeName(), null, attr.getNodeValue());
}
return attributes;
}
/**
* Copy all children from 'source' to 'dest', within the context of the specified page.
* @param page the page which the nodes belong to
* @param source the node to copy from
* @param dest the node to copy to
*/
private static void copy(final SgmlPage page, final Node source, final DomNode dest) {
final NodeList nodeChildren = source.getChildNodes();
for (int i = 0; i < nodeChildren.getLength(); i++) {
final Node child = nodeChildren.item(i);
switch (child.getNodeType()) {
case Node.ELEMENT_NODE:
final DomNode childXml = createFrom(page, child);
dest.appendChild(childXml);
copy(page, child, childXml);
break;
case Node.TEXT_NODE:
dest.appendChild(new DomText(page, child.getNodeValue()));
break;
case Node.CDATA_SECTION_NODE:
dest.appendChild(new DomCDataSection(page, child.getNodeValue()));
break;
case Node.COMMENT_NODE:
dest.appendChild(new DomComment(page, child.getNodeValue()));
break;
case Node.PROCESSING_INSTRUCTION_NODE:
dest.appendChild(new DomProcessingInstruction(page, child.getNodeName(), child.getNodeValue()));
break;
default:
LOG.warn("NodeType " + child.getNodeType()
+ " (" + child.getNodeName() + ") is not yet supported.");
}
}
}
/**
* Search for the namespace URI of the given prefix, starting from the specified element.
* @param element the element to start searching from
* @param prefix the namespace prefix
* @return the namespace URI bound to the prefix; or null if there is no such namespace
*/
public static String lookupNamespaceURI(final DomElement element, final String prefix) {
String uri = element.getAttribute("xmlns:" + prefix);
if (uri == DomElement.ATTRIBUTE_NOT_DEFINED) {
final DomNode parentNode = element.getParentNode();
if (parentNode instanceof DomElement) {
uri = lookupNamespaceURI((DomElement) parentNode, prefix);
}
}
return uri;
}
/**
* Search for the prefix associated with specified namespace URI.
* @param element the element to start searching from
* @param namespace the namespace prefix
* @return the prefix bound to the namespace URI; or null if there is no such namespace
*/
public static String lookupPrefix(final DomElement element, final String namespace) {
final Map<String, DomAttr> attributes = element.getAttributesMap();
for (final String name : attributes.keySet()) {
if (name.startsWith("xmlns:") && attributes.get(name).getValue().equals(namespace)) {
return name.substring(6);
}
}
for (final DomNode child : element.getChildren()) {
if (child instanceof DomElement) {
final String prefix = lookupPrefix((DomElement) child, namespace);
if (prefix != null) {
return prefix;
}
}
}
return null;
}
}