ruleset.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: RuleSet.java,v 1.2 2003/06/10 16:18:35 per_nyfelt Exp $
 */

package org.dom4j.rule;

import org.dom4j.Node;

import java.util.ArrayList;
import java.util.Collections;

/** <p><code>RuleSet</code> manages a set of rules which are sorted
  * in order of relevance according to the XSLT defined conflict
  * resolution policy. This makes finding the correct rule for 
  * a DOM4J Node using the XSLT processing model efficient as the
  * rules can be evaluated in order of priority.</p>
  *
  * @author <a href="mailto:[e-mail]">James Strachan</a>
  * @version $Revision: 1.2 $
  */
public class RuleSet {

    /** An unordered list of Rule objects */
    private ArrayList rules = new ArrayList();
    
    /** A lazily evaluated and cached array of rules sorted */
    private Rule[] ruleArray;
    
    public RuleSet() {
    }
    
    public String toString() {
        return super.toString() + " [RuleSet: " + rules + " ]";
    }
    
    
    /** Performs an XSLT processing model match for the rule
      * which matches the given Node the best.
      *
      * @param mode is the mode associated with the rule if any
      * @param node is the DOM4J Node to match against
      * @return the matching Rule or no rule if none matched
      */
    public Rule getMatchingRule( Node node ) {
        Rule[] rules = getRuleArray();
        for ( int i = rules.length - 1; i >= 0; i-- ) {
            Rule rule = rules[i];
            if ( rule.matches( node ) ) {
                return rule;
            }
        }
        return null;
    }
    
    public void addRule(Rule rule) {
        rules.add( rule );
        ruleArray = null;
    }
    
    public void removeRule(Rule rule) {
        rules.remove( rule );
        ruleArray = null;
    }
    
    /** Adds all the rules to this RuleSet from the given other rule set. 
      */
    public void addAll(RuleSet that) {
        rules.addAll( that.rules );
        ruleArray = null;
    }
    
    /** Returns an array of sorted rules.
      *
      * @return the rules as a sorted array in ascending precendence
      * so that the rules at the end of the array should be used first
      */
    protected Rule[] getRuleArray() {
        if ( ruleArray == null ) {
            Collections.sort( rules );
            int size = rules.size();
            ruleArray = new Rule[ size ];
            rules.toArray( ruleArray );
        }
        return ruleArray;
    }

}




/*
 * 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: RuleSet.java,v 1.2 2003/06/10 16:18:35 per_nyfelt Exp $
 */