/*
* JasperReports - Free Java Reporting Library.
* Copyright (C) 2001 - 2009 Jaspersoft Corporation. All rights reserved.
* http://www.jaspersoft.com
*
* Unless you have purchased a commercial license agreement from Jaspersoft,
* the following license terms apply:
*
* This program is part of JasperReports.
*
* JasperReports is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* JasperReports is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with JasperReports. If not, see <http://www.gnu.org/licenses/>.
*/
package net.sf.jasperreports.engine.util.xml;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import net.sf.jasperreports.engine.JRException;
import org.apache.commons.collections.ReferenceMap;
import org.jaxen.JaxenException;
import org.jaxen.XPath;
import org.jaxen.dom.DOMXPath;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* XPath executer implementation that uses <a href="http://jaxen.org/" target="_blank">Jaxen</a>.
*
* @author Lucian Chirita (lucianc@users.sourceforge.net)
* @version $Id: JaxenXPathExecuter.java 3034 2009-08-27 11:58:04Z teodord $
*/
public class JaxenXPathExecuter implements JRXPathExecuter
{
private final Map cachedXPaths = new ReferenceMap();//soft cache
public JaxenXPathExecuter()
{
}
protected XPath getXPath(String expression) throws JRException
{
XPath xPath = (XPath) cachedXPaths.get(expression);
if (xPath == null)
{
try
{
xPath = new DOMXPath(expression);
}
catch (JaxenException e)
{
throw new JRException("XPath compilation failed. Expression: " + expression, e);
}
cachedXPaths.put(expression, xPath);
}
return xPath;
}
public NodeList selectNodeList(Node contextNode, String expression) throws JRException
{
try
{
XPath xpath = getXPath(expression);
Object object = xpath.evaluate(contextNode);
List nodes;
if (object instanceof List)
{
nodes = (List) object;
}
else
{
nodes = new ArrayList();
nodes.add(object);
}
return new NodeListWrapper(nodes);
}
catch (JaxenException e)
{
throw new JRException("XPath selection failed. Expression: " + expression, e);
}
}
public Object selectObject(Node contextNode, String expression) throws JRException
{
try
{
XPath xpath = new DOMXPath(expression);
Object object = xpath.evaluate(contextNode);
Object value;
if (object instanceof List)
{
List list = (List) object;
if (list.isEmpty())
{
value = null;
}
else
{
value = list.get(0);
}
}
else if (object instanceof Number || object instanceof Boolean)
{
value = object;
}
else
{
value = object.toString();
}
return value;
}
catch (JaxenException e)
{
throw new JRException("XPath selection failed. Expression: " + expression, e);
}
}
protected static final class NodeListWrapper implements NodeList
{
private final List nodes;
public NodeListWrapper(List nodes)
{
this.nodes = nodes;
}
public int getLength()
{
return nodes.size();
}
public Node item(int index)
{
return (Node) nodes.get(index);
}
}
}