Mega Code Archive
Convert Hashtable to a Node
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/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
/*
* $Id: Hashtree2Node.java 475902 2006-11-16 20:03:16Z minchau $
*/
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
/**
* Simple static utility to convert Hashtable to a Node.
*
* @see org.apache.xalan.xslt.EnvironmentCheck
* @see org.apache.xalan.lib.Extensions
* @author shane_curcuru@us.ibm.com
* @version $Id: Hashtree2Node.java 475902 2006-11-16 20:03:16Z minchau $
* @xsl.usage general
*/
public abstract class Hashtree2Node
{
/**
* Convert a Hashtable into a Node tree.
*
* <p>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.</p>
*
* <p>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().</p>
*
* @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
*/
public static void appendHashToNode(Hashtable hash, String name,
Node container, Document factory)
{
// 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();
List v = new ArrayList();
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.add(keyStr);
v.add((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
Iterator it = v.iterator();
while (it.hasNext())
{
// Retrieve name and hash in two steps
String n = (String) it.next();
Hashtable h = (Hashtable) it.next();
appendHashToNode(h, n, hashNode, factory);
}
}
catch (Exception e2)
{
// Ooops, just bail (suggestions for a safe thing
// to do in this case appreciated)
e2.printStackTrace();
}
}
}
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