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Posted to commits@xalan.apache.org by dl...@locus.apache.org on 2000/09/28 19:03:22 UTC
cvs commit: xml-xalan/java/src/org/apache/xalan/lib NodeSetOperations.java
dleslie 00/09/28 10:03:21
Added: java/src/org/apache/xalan/lib NodeSetOperations.java
Log:
Node-set extension functions: intersection, difference, distinct,
and hasSameNodes.
Revision Changes Path
1.1 xml-xalan/java/src/org/apache/xalan/lib/NodeSetOperations.java
Index: NodeSetOperations.java
===================================================================
/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 2000 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, Lotus
* Development Corporation., http://www.lotus.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xalan.lib;
import org.w3c.dom.Node;
import org.w3c.dom.traversal.NodeIterator;
import org.apache.xpath.NodeSet;
import java.util.Hashtable;
import org.xml.sax.SAXException;
/**
* <meta name="usage" content="general"/>
* Extension functions that perform set operations
* with one or two node-sets.
*/
public class NodeSetOperations
{
/**
* Returns the intersection of two node-sets.
* @param n1 NodeIterator for first node-set
* @param ni2 NodeIterator for second node-set
* @return a NodeSet containing the nodes in ni1 that are also
* in ni2
*/
public static NodeSet intersection(NodeIterator ni1, NodeIterator ni2)
throws org.xml.sax.SAXException
{
NodeSet ns1 = new NodeSet(ni1);
NodeSet ns2 = new NodeSet(ni2);
NodeSet inter= new NodeSet();
inter.setShouldCacheNodes(true);
for (int i=0; i < ns1.getLength(); i++)
{
Node n = ns1.elementAt(i);
if(ns2.contains(n))
inter.addElement(n);
}
return inter;
}
/**
* Returns the difference between two node-sets.
* @param n1 NodeIterator for first node-set
* @param ni2 NodeIterator for second node-set
* @return a NodeSet containing the nodes in ni1 that are not
* in ni2
*/
public static NodeSet difference(NodeIterator ni1, NodeIterator ni2)
throws org.xml.sax.SAXException
{
NodeSet ns1 = new NodeSet(ni1);
NodeSet ns2 = new NodeSet(ni2);
NodeSet inter= new NodeSet();
NodeSet diff = new NodeSet();
diff.setShouldCacheNodes(true);
for (int i = 0; i < ns1.getLength(); i++)
{
Node n = ns1.elementAt(i);
if(!ns2.contains(n))
diff.addElement(n);
}
return diff;
}
/**
* Returns NodeIterator for a node-set containing distinct string values.
* @param ni NodeIterator for node-set
* @return a NodeSet with nodes from ni containing distinct string values.
* In other words, if more than one node in ni contains the same string value,
* only include the first such node found.
*/
public static NodeSet distinct(NodeIterator ni)
throws org.xml.sax.SAXException
{
NodeSet ns = new NodeSet(ni);
NodeSet dist = new NodeSet();
dist.setShouldCacheNodes(true);
Hashtable stringTable = new Hashtable();
for (int i = 0; i < ns.getLength(); i++)
{
Node n = ns.elementAt(i);
String key = n.getNodeValue();
if (!stringTable.containsKey(key))
{
stringTable.put(key, n);
dist.addElement(n);
}
}
return dist;
}
/**
* Returns true of both node-sets contain the same set of nodes.
* @param n1 NodeIterator for first node-set
* @param ni2 NodeIterator for second node-set
* @return true if ni1 and ni2 contain exactly the same set of nodes.
*/
public static boolean hasSameNodes(NodeIterator ni1, NodeIterator ni2)
{
NodeSet ns1 = new NodeSet(ni1);
NodeSet ns2 = new NodeSet(ni2);
if (ns1.getLength() != ns2.getLength())
return false;
for (int i = 0; i < ns1.getLength(); i++)
{
Node n = ns1.elementAt(i);
if(!ns2.contains(n))
return false;
}
return true;
}
}