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Hashtree2Node.javaAPI DocJava SE 5 API4980Fri Aug 26 14:56:04 BST 2005com.sun.org.apache.xml.internal.utils

Hashtree2Node

public abstract class Hashtree2Node extends Object
Simple static utility to convert Hashtable to a Node. Please maintain JDK 1.1.x compatibility; no Collections!
see
com.sun.org.apache.xalan.internal.xslt.EnvironmentCheck
see
com.sun.org.apache.xalan.internal.lib.Extensions
author
shane_curcuru@us.ibm.com
version
$Id: Hashtree2Node.java,v 1.6 2004/02/17 04:21:14 minchau Exp $
xsl.usage
general

Fields Summary
Constructors Summary
Methods Summary
public static voidappendHashToNode(java.util.Hashtable hash, java.lang.String name, org.w3c.dom.Node container, org.w3c.dom.Document factory)
Convert a Hashtable into a Node tree.

The hash may have either Hashtables as values (in which case we recurse) or other values, in which case we print them as <item> elements, with a 'key' attribute with the value of the key, and the element contents as the value.

If args are null we simply return without doing anything. If we encounter an error, we will attempt to add an 'ERROR' Element with exception info; if that doesn't work we simply return without doing anything else byt printStackTrace().

param
hash to get info from (may have sub-hashtables)
param
name to use as parent element for appended node futurework could have namespace and prefix as well
param
container Node to append our report to
param
factory Document providing createElement, etc. services

        // Required arguments must not be null
        if ((null == container) || (null == factory) || (null == hash))
        {
            return;
        }

        // name we will provide a default value for
        String elemName = null;
        if ((null == name) || ("".equals(name)))
            elemName = "appendHashToNode";
        else
            elemName = name;

        try
        {
            Element hashNode = factory.createElement(elemName);
            container.appendChild(hashNode);

            Enumeration keys = hash.keys();
            Vector v = new Vector();

            while (keys.hasMoreElements())
            {
                Object key = keys.nextElement();
                String keyStr = key.toString();
                Object item = hash.get(key);

                if (item instanceof Hashtable)
                {
                    // Ensure a pre-order traversal; add this hashes 
                    //  items before recursing to child hashes
                    // Save name and hash in two steps
                    v.addElement(keyStr);
                    v.addElement((Hashtable) item);
                }
                else
                {
                    try
                    {
                        // Add item to node
                        Element node = factory.createElement("item");
                        node.setAttribute("key", keyStr);
                        node.appendChild(factory.createTextNode((String)item));
                        hashNode.appendChild(node);
                    }
                    catch (Exception e)
                    {
                        Element node = factory.createElement("item");
                        node.setAttribute("key", keyStr);
                        node.appendChild(factory.createTextNode("ERROR: Reading " + key + " threw: " + e.toString()));
                        hashNode.appendChild(node);
                    }
                }
            }

            // Now go back and do the saved hashes
            keys = v.elements();
            while (keys.hasMoreElements())
            {
                // Retrieve name and hash in two steps
                String n = (String) keys.nextElement();
                Hashtable h = (Hashtable) keys.nextElement();

                appendHashToNode(h, n, hashNode, factory);
            }
        }
        catch (Exception e2)
        {
            // Ooops, just bail (suggestions for a safe thing 
            //  to do in this case appreciated)
            e2.printStackTrace();
        }