xmladapter4queries.java

来自「Mandarax是一个规则引擎的纯Java实现。它支持多类型的事实和基于反映的规」· Java 代码 · 共 114 行

package org.mandarax.xkb.framework;

/**
 *  Copyright (C) 1999-2004  Jens Dietrich (mailto:[e-mail])
 *
 *  This library 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 2 of the License, or (at your option) any later version.
 *
 *  This library 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 this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Vector;

import org.jdom.Element;
import org.mandarax.kernel.Fact;
import org.mandarax.kernel.LogicFactory;
import org.mandarax.kernel.Query;
import org.mandarax.xkb.XKBException;
/**
 * An adapter class for queries.
 * @see org.mandarax.kernel.Rule
 * @author <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</A>
 * @version 3.4 <7 March 05>
 * @since 1.9 
 * @deprecated from v 3.4 - support for new features such as validation will not be added to XKB, please use ZKB instead
 */

public class XMLAdapter4Queries extends AbstractXMLAdapter {
      public static final String QUERY = "query";
      public static final String BODY = "_body";
      public static final String NAME = "name";
/**
 * Export an object, i.e., convert it to an element in the DOM.
 * @param obj an object
 * @param driver the generic driver
 * @param cache a cache used in order to associate the same
 * id with various occurences of the same object
 * @exception an XKBException is thrown if export fails
 */
public Element exportObject(Object obj,GenericDriver driver,Map cache) throws  XKBException {
      check(obj,Query.class);
      Query query = (Query)obj;
      Element e = new Element(QUERY);
      String queryName = query.getName();
      if (queryName==null) queryName = "";
      e.setAttribute(NAME,queryName);
      Element eBody = new Element(BODY);
      e.addContent(eBody);
      Fact[] queryFacts = query.getFacts();
      for (int i=0;i<queryFacts.length;i++) {
            Element el = exportObject(queryFacts[i],GenericDriver.FACT,driver,cache);
            eBody.addContent(el);
      }
      return e;
}
/**
 * Build an object from an XML element.
 * @param e an element
 * @param driver the generic driver
 * @param cache a cache used to identify objects that have the same id
 * @param lfactory the logic factory used to create objects
 * @exception an XKBException is thrown if import fails
 */
public Object importObject(Element e,GenericDriver driver,Map cache,LogicFactory lfactory) throws XKBException {
      // get  body
      Element eBody = e.getChild(BODY);
      List body = new Vector();
      XMLAdapter adapter4Facts = null;
      List children = eBody.getChildren();
      for (Iterator it = children.iterator();it.hasNext();) {
              Element eFact = (Element)it.next();
              if (adapter4Facts==null) adapter4Facts = driver.getAdapterByTagName(eFact.getName());
              Fact queryFact = (Fact)adapter4Facts.importObject(eFact,driver,cache,lfactory);
              body.add(queryFact);

      }
      Fact[] facts = new Fact[body.size()];
      for (int i=0;i<body.size();i++) facts[i]=(Fact)body.get(i);
	  String queryName = e.getAttributeValue(NAME);
		
      // build query
      Query q = lfactory.createQuery(facts,queryName==null?"":queryName);
      if (queryName==null) q.setName(q.toString());
      
      return q;
}
/**
 * Get the name of the associated tag (element).
 * @return a string
 */
public String getTagName() {
      return QUERY;
}
/**
 * Get the kind of object the adapter can export/import.
 * @return a string
 */
public String getKindOfObject() {
      return GenericDriver.QUERY;
}
}