xpathpattern.java

Java的面向对象数据库系统的源代码

/*
 * Copyright 2001 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 *
 * $Id: XPathPattern.java,v 1.3 2003/11/02 18:05:00 per_nyfelt Exp $
 */

package org.dom4j.xpath;

import org.dom4j.InvalidXPathException;
import org.dom4j.Node;
import org.dom4j.XPathException;
import org.jaxen.*;
import org.jaxen.dom4j.DocumentNavigator;
import org.jaxen.pattern.Pattern;
import org.jaxen.pattern.PatternParser;

import java.util.ArrayList;

/** <p><code>XPathPattern</code> is an implementation of Pattern
  * which uses an XPath xpath.</p>
  *
  * @author <a href="mailto:[e-mail]">James Strachan</a>
  * @version $Revision: 1.3 $
  */
public class XPathPattern implements org.dom4j.rule.Pattern {

    private String text;
    private Pattern pattern;
    private Context context;


    public XPathPattern(Pattern pattern) {
        this.pattern = pattern;
        this.text = pattern.getText();
        this.context = new Context( getContextSupport() );
    }

    public XPathPattern(String text) {
        this.text = text;
        this.context = new Context( getContextSupport() );
        try {
            this.pattern = PatternParser.parse( text );
        }
        catch (Exception e) {
            throw new InvalidXPathException( text, e.getMessage() );
        }
    }

    public boolean matches( Node node ) {
        try {
            ArrayList list = new ArrayList(1);
            list.add( node );
            context.setNodeSet( list );
            return pattern.matches( node, context );
        }
        catch (JaxenException e) {
            handleJaxenException(e);
            return false;
        }
    }

    public String getText() {
        return text;
    }


    public double getPriority()  {
        return pattern.getPriority();
    }

    public org.dom4j.rule.Pattern[] getUnionPatterns() {
        Pattern[] patterns = pattern.getUnionPatterns();
        if ( patterns != null ) {
            int size = patterns.length;
            XPathPattern[] answer = new XPathPattern[size];
            for ( int i = 0; i < size; i++ ) {
                answer[i] = new XPathPattern( patterns[i] );
            }
            return answer;
        }
        return null;
    }

    public short getMatchType() {
        return pattern.getMatchType();
    }

    public String getMatchesNodeName() {
        return pattern.getMatchesNodeName();
    }

    public void setVariableContext(VariableContext variableContext) {
        context.getContextSupport().setVariableContext( variableContext );
    }


    public String toString() {
        return "[XPathPattern: text: " + text + " Pattern: " + pattern + "]";
    }

    protected ContextSupport getContextSupport() {
        return new ContextSupport(
            new SimpleNamespaceContext(),
            XPathFunctionContext.getInstance(),
            new SimpleVariableContext(),
            DocumentNavigator.getInstance()
        );
    }

    protected void handleJaxenException(JaxenException e) throws XPathException {
        throw new XPathException(text, e);
    }
}




/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
 *    statements and notices.  Redistributions must also contain a
 *    copy of this document.
 *
 * 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 name "DOM4J" must not be used to endorse or promote
 *    products derived from this Software without prior written
 *    permission of MetaStuff, Ltd.  For written permission,
 *    please contact [e-mail].
 *
 * 4. Products derived from this Software may not be called "DOM4J"
 *    nor may "DOM4J" appear in their names without prior written
 *    permission of MetaStuff, Ltd. DOM4J is a registered
 *    trademark of MetaStuff, Ltd.
 *
 * 5. Due credit should be given to the DOM4J Project
 *    (http://dom4j.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS
 * ``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
 * METASTUFF, LTD. 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.
 *
 * Copyright 2001 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * $Id: XPathPattern.java,v 1.3 2003/11/02 18:05:00 per_nyfelt Exp $
 */