/* * @(#)XMLParsing.java	1.5 03/05/18 *  * Copyright 2004 Sun Microsystems, Inc. All rights reserved. * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms. */package jnlp.sample.servlet;import javax.xml.parsers.*;import java.util.ArrayList;import java.util.List;import org.xml.sax.*;import org.w3c.dom.*;/** Contains handy methods for looking up information *  stored in XMLNodes. */public class XMLParsing {           public static XMLNode convert(Node n) {        if (n == null) {	    return null;        } else if (n instanceof Text) {	    Text tn = (Text)n;	    return new XMLNode(tn.getNodeValue());        } else if (n instanceof Element) {	    Element en = (Element)n;	    	    XMLAttribute xmlatts = null;	    NamedNodeMap attributes = en.getAttributes();	    for(int i = attributes.getLength() - 1; i >= 0; i--) {		Attr ar = (Attr)attributes.item(i);		xmlatts = new XMLAttribute(ar.getName(), ar.getValue(), xmlatts);	    }	    	    // Convert childern	    XMLNode thisNode = new XMLNode(en.getNodeName(), xmlatts, null, null);;	    XMLNode last = null;	    Node nn = en.getFirstChild();	    while(nn != null) {		if (thisNode.getNested() == null) {		    last = convert(nn);		    thisNode.setNested(last);		} else {		    XMLNode nnode = convert(nn);		    last.setNext(nnode);		    last = nnode;		}		last.setParent(thisNode);		nn = nn.getNextSibling();	    }	    	    return thisNode;        }        return null;    }        /** Returns true if the path exists in the document, otherwise false */    static public boolean isElementPath(XMLNode root, String path) {        return findElementPath(root, path) != null;    }            /** Returns a string describing the current location in the DOM */    static public String getPathString(XMLNode e) {        return (e == null || !(e.isElement())) ? "" : getPathString(e.getParent()) + "<" + e.getName() + ">";    }            /** Like getElementContents(...) but with a defaultValue of null */    static public String getElementContent(XMLNode root, String path) {        return getElementContent(root, path, null);    }        /** Like getElementContents(...) but with a defaultValue of null */    static public String[] getMultiElementContent(XMLNode root, String path) {        final List list = new ArrayList();	visitElements(root, path, new ElementVisitor() {		    public void visitElement(XMLNode n) {			String value = getElementContent(n, "");			if (value != null) list.add(value);		    }		});	if (list.size() == 0) return null;	return (String[])list.toArray(new String[list.size()]);    }        /** Returns the value of the last element tag in the path, e.g.,  <..><tag>value</tag>. The DOM is assumes     *  to be normalized. If no value is found, the defaultvalue is returned     */    static public String getElementContent(XMLNode root, String path, String defaultvalue) {        XMLNode e = findElementPath(root, path);	if (e == null) return defaultvalue;        XMLNode n = e.getNested();        if (n != null && !n.isElement()) return n.getName();	return defaultvalue;    }        /** Parses a path string of the form <tag1><tag2><tag3> and returns the specific Element     *  node for that tag, or null if it does not exist. If multiple elements exists with same     *  path the first is returned     */    static public XMLNode findElementPath(XMLNode elem, String path) {	// End condition. Root null -> path does not exist	if (elem == null) return null;	// End condition. String empty, return current root	if (path == null || path.length() == 0) return elem;		// Strip of first tag	int idx = path.indexOf('>');	String head = path.substring(1, idx);	String tail = path.substring(idx + 1);	return findElementPath(findChildElement(elem, head), tail);    }        /** Returns an child element with the current tag name or null. */    static public XMLNode findChildElement(XMLNode elem, String tag) {	XMLNode n = elem.getNested();	while(n != null) {	    if (n.isElement() && n.getName().equals(tag)) return n;	    n = n.getNext();	}	return null;    }        /** Iterator class */    public abstract static class ElementVisitor {	abstract public void visitElement(XMLNode e);    }        /** Visits all elements which matches the <path>. The iteration is only     *  done on the last elment in the path.     */    static public void visitElements(XMLNode root, String path, ElementVisitor ev) {	// Get last element in path	int idx = path.lastIndexOf('<');	String head = path.substring(0, idx);	String tag  = path.substring(idx + 1, path.length() - 1);		XMLNode elem = findElementPath(root, head);	if (elem == null) return;		// Iterate through all child nodes	XMLNode n = elem.getNested();	while(n != null) {	    if (n.isElement() && n.getName().equals(tag)) {		ev.visitElement(n);	    }	    n = n.getNext();	}    }        static public void visitChildrenElements(XMLNode elem, ElementVisitor ev) {	// Iterate through all child nodes	XMLNode n = elem.getNested();	while(n != null) {	    if (n.isElement()) ev.visitElement(n);	    n = n.getNext();	}    }}