org.jsoup.helper.W3CDom Maven / Gradle / Ivy
package org.jsoup.helper;
import org.jsoup.nodes.Attribute;
import org.jsoup.nodes.Attributes;
import org.jsoup.select.NodeTraversor;
import org.jsoup.select.NodeVisitor;
import org.w3c.dom.Comment;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Text;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.io.StringWriter;
import java.util.HashMap;
/**
* Helper class to transform a {@link org.jsoup.nodes.Document} to a {@link org.w3c.dom.Document org.w3c.dom.Document},
* for integration with toolsets that use the W3C DOM.
*
* This class is currently experimental, please provide feedback on utility and any problems experienced.
*
*/
public class W3CDom {
protected DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
/**
* Convert a jsoup Document to a W3C Document.
* @param in jsoup doc
* @return w3c doc
*/
public Document fromJsoup(org.jsoup.nodes.Document in) {
Validate.notNull(in);
DocumentBuilder builder;
try {
//set the factory to be namespace-aware
factory.setNamespaceAware(true);
builder = factory.newDocumentBuilder();
Document out = builder.newDocument();
convert(in, out);
return out;
} catch (ParserConfigurationException e) {
throw new IllegalStateException(e);
}
}
/**
* Converts a jsoup document into the provided W3C Document. If required, you can set options on the output document
* before converting.
* @param in jsoup doc
* @param out w3c doc
* @see org.jsoup.helper.W3CDom#fromJsoup(org.jsoup.nodes.Document)
*/
public void convert(org.jsoup.nodes.Document in, Document out) {
if (!StringUtil.isBlank(in.location()))
out.setDocumentURI(in.location());
org.jsoup.nodes.Element rootEl = in.child(0); // skip the #root node
NodeTraversor traversor = new NodeTraversor(new W3CBuilder(out));
traversor.traverse(rootEl);
}
/**
* Implements the conversion by walking the input.
*/
protected static class W3CBuilder implements NodeVisitor {
private static final String xmlnsKey = "xmlns";
private static final String xmlnsPrefix = "xmlns:";
private final Document doc;
private final HashMap namespaces = new HashMap(); // prefix => urn
private Element dest;
public W3CBuilder(Document doc) {
this.doc = doc;
}
public void head(org.jsoup.nodes.Node source, int depth) {
if (source instanceof org.jsoup.nodes.Element) {
org.jsoup.nodes.Element sourceEl = (org.jsoup.nodes.Element) source;
String prefix = updateNamespaces(sourceEl);
String namespace = namespaces.get(prefix);
Element el = doc.createElementNS(namespace, sourceEl.tagName());
copyAttributes(sourceEl, el);
if (dest == null) { // sets up the root
doc.appendChild(el);
} else {
dest.appendChild(el);
}
dest = el; // descend
} else if (source instanceof org.jsoup.nodes.TextNode) {
org.jsoup.nodes.TextNode sourceText = (org.jsoup.nodes.TextNode) source;
Text text = doc.createTextNode(sourceText.getWholeText());
dest.appendChild(text);
} else if (source instanceof org.jsoup.nodes.Comment) {
org.jsoup.nodes.Comment sourceComment = (org.jsoup.nodes.Comment) source;
Comment comment = doc.createComment(sourceComment.getData());
dest.appendChild(comment);
} else if (source instanceof org.jsoup.nodes.DataNode) {
org.jsoup.nodes.DataNode sourceData = (org.jsoup.nodes.DataNode) source;
Text node = doc.createTextNode(sourceData.getWholeData());
dest.appendChild(node);
} else {
// unhandled
}
}
public void tail(org.jsoup.nodes.Node source, int depth) {
if (source instanceof org.jsoup.nodes.Element && dest.getParentNode() instanceof Element) {
dest = (Element) dest.getParentNode(); // undescend. cromulent.
}
}
private void copyAttributes(org.jsoup.nodes.Node source, Element el) {
for (Attribute attribute : source.attributes()) {
// valid xml attribute names are: ^[a-zA-Z_:][-a-zA-Z0-9_:.]
String key = attribute.getKey().replaceAll("[^-a-zA-Z0-9_:.]", "");
if (key.matches("[a-zA-Z_:]{1}[-a-zA-Z0-9_:.]*"))
el.setAttribute(key, attribute.getValue());
}
}
/**
* Finds any namespaces defined in this element. Returns any tag prefix.
*/
private String updateNamespaces(org.jsoup.nodes.Element el) {
// scan the element for namespace declarations
// like: xmlns="blah" or xmlns:prefix="blah"
Attributes attributes = el.attributes();
for (Attribute attr : attributes) {
String key = attr.getKey();
String prefix;
if (key.equals(xmlnsKey)) {
prefix = "";
} else if (key.startsWith(xmlnsPrefix)) {
prefix = key.substring(xmlnsPrefix.length());
} else {
continue;
}
namespaces.put(prefix, attr.getValue());
}
// get the element prefix if any
int pos = el.tagName().indexOf(":");
return pos > 0 ? el.tagName().substring(0, pos) : "";
}
}
/**
* Serialize a W3C document to a String.
* @param doc Document
* @return Document as string
*/
public String asString(Document doc) {
try {
DOMSource domSource = new DOMSource(doc);
StringWriter writer = new StringWriter();
StreamResult result = new StreamResult(writer);
TransformerFactory tf = TransformerFactory.newInstance();
Transformer transformer = tf.newTransformer();
transformer.transform(domSource, result);
return writer.toString();
} catch (TransformerException e) {
throw new IllegalStateException(e);
}
}
}