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

package org.dom4j.rule;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;

import java.util.HashMap;
import java.util.Map;


/** <p><code>Mode</code> manages a number of RuleSet instances 
  * for the mode in a stylesheet. 
  * It is responsible for finding the correct rule for a given DOM4J Node 
  * using the XSLT processing model uses the smallest possible RuleSet to 
  * reduce the number of Rule evaluations.</p>
  *
  * @author <a href="mailto:[e-mail]">James Strachan</a>
  * @version $Revision: 1.2 $
  */
public class Mode {

    private RuleSet[] ruleSets = new RuleSet[ Pattern.NUMBER_OF_TYPES ];
    
    /** Map of exact (local) element names to RuleSet instances */
    private Map elementNameRuleSets;
    
    /** Map of exact (local) attribute names to RuleSet instances */
    private Map attributeNameRuleSets;

    public Mode() {
    }

    /** Runs the actions associated with the given node 
      */
    public void fireRule( Node node ) throws Exception {
        if ( node != null ) {
            Rule rule = getMatchingRule( node );
            if ( rule != null ) {
                Action action = rule.getAction();
                if ( action != null ) {
                    action.run( node );
                }
            }
        }
    }
    
    public void applyTemplates( Element element ) throws Exception {
        for ( int i = 0, size = element.attributeCount(); i < size; i++ ) {
            Attribute attribute = element.attribute(i);
            fireRule( attribute );
        }
        for ( int i = 0, size = element.nodeCount(); i < size; i++ ) {
            Node node = element.node(i);
            fireRule( node );
        }
    }
    
    public void applyTemplates( Document document ) throws Exception {
        for ( int i = 0, size = document.nodeCount(); i < size; i++ ) {
            Node node = document.node(i);
            fireRule( node );
        }
    }
    
    
    public void addRule(Rule rule) {
        int matchType = rule.getMatchType();
        String name = rule.getMatchesNodeName();
        if ( name != null ) {
            if ( matchType == Node.ELEMENT_NODE ) {
                elementNameRuleSets = addToNameMap( 
                    elementNameRuleSets, name, rule 
                );
            }
            else if ( matchType == Node.ATTRIBUTE_NODE ) { 
                attributeNameRuleSets = addToNameMap( 
                    attributeNameRuleSets, name, rule 
                );
            }
        }
        if ( matchType >= Pattern.NUMBER_OF_TYPES ) {
            matchType = Pattern.ANY_NODE;
        }
        if ( matchType == Pattern.ANY_NODE ) {
            // add rule to all other RuleSets if they exist
            for ( int i = 1, size = ruleSets.length; i < size; i++ ) {
                RuleSet ruleSet = ruleSets[i];
                if ( ruleSet != null ) {
                    ruleSet.addRule( rule );
                }
            }
        }
        getRuleSet( matchType ).addRule( rule );
    }
    
    public void removeRule(Rule rule) {
        int matchType = rule.getMatchType();
        String name = rule.getMatchesNodeName();
        if ( name != null ) {
            if ( matchType == Node.ELEMENT_NODE ) {
                removeFromNameMap( elementNameRuleSets, name, rule );
            }
            else if ( matchType == Node.ATTRIBUTE_NODE ) { 
                removeFromNameMap( attributeNameRuleSets, name, rule );
            }
        }
        if ( matchType >= Pattern.NUMBER_OF_TYPES ) {
            matchType = Pattern.ANY_NODE;
        }
        getRuleSet( matchType ).removeRule( rule );
        if ( matchType != Pattern.ANY_NODE ) {
            getRuleSet( Pattern.ANY_NODE ).removeRule( rule );
        }
    }

    /** Performs an XSLT processing model match for the rule
      * which matches the given Node the best.
      *
      * @param node is the DOM4J Node to match against
      * @return the matching Rule or no rule if none matched
      */
    public Rule getMatchingRule(Node node) {
        int matchType = node.getNodeType();
        if ( matchType == Node.ELEMENT_NODE ) {
            if ( elementNameRuleSets != null ) {
                String name = node.getName();
                RuleSet ruleSet = (RuleSet) elementNameRuleSets.get( name );
                if ( ruleSet != null ) {
                    Rule answer = ruleSet.getMatchingRule( node );
                    if ( answer != null ) {
                        return answer;
                    }
                }
            }
        }
        else if ( matchType == Node.ATTRIBUTE_NODE ) { 
            if ( attributeNameRuleSets != null ) {
                String name = node.getName();
                RuleSet ruleSet = (RuleSet) attributeNameRuleSets.get( name );
                if ( ruleSet != null ) {
                    Rule answer = ruleSet.getMatchingRule( node );
                    if ( answer != null ) {
                        return answer;
                    }
                }
            }
        }
        if ( matchType < 0 || matchType >= ruleSets.length ) {
            matchType = Pattern.ANY_NODE;
        }
        Rule answer = null;
        RuleSet ruleSet = ruleSets[ matchType ];
        if ( ruleSet != null ) {
            // try rules that match this kind of node first
            answer = ruleSet.getMatchingRule( node );
        }
        if ( answer == null && matchType != Pattern.ANY_NODE ) {
            // try general rules that match any kind of node
            ruleSet = ruleSets[ Pattern.ANY_NODE ];
            if ( ruleSet != null ) {
                answer = ruleSet.getMatchingRule( node );
            }
        }
        return answer;
    }

    
    /** @return the RuleSet for the given matching type.
      * This method will never return null, a new instance will be created.
      */
    protected RuleSet getRuleSet( int matchType ) {
        RuleSet ruleSet = ruleSets[ matchType ];
        if ( ruleSet == null ) {
            ruleSet = new RuleSet();
            ruleSets[ matchType ] = ruleSet;
            
            // add the patterns that match any node
            if ( matchType != Pattern.ANY_NODE ) {
                RuleSet allRules = ruleSets[ Pattern.ANY_NODE ];
                if ( allRules != null ) {
                    ruleSet.addAll( allRules );
                }
            }
        }
        return ruleSet;
    }

    
    /** Adds the Rule to a RuleSet for the given name.
      * @return the Map (which will be created if the given map was null
      */
    protected Map addToNameMap( Map map, String name, Rule rule ) {
        if ( map == null ) {
            map = new HashMap();
        }
        RuleSet ruleSet = (RuleSet) map.get( name );
        if ( ruleSet == null ) {
            ruleSet = new RuleSet();
            map.put( name, ruleSet );
        }
        ruleSet.addRule( rule );
        return map;
    }

    protected void removeFromNameMap( Map map, String name, Rule rule ) {
        if ( map != null ) {
            RuleSet ruleSet = (RuleSet) map.get( name );
            if ( ruleSet != null ) {
                ruleSet.removeRule( rule );
            }
        }
    }
    
}




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