testclausesetevents3.java

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则

/*
 * Copyright (C) 1999-2004 <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</a>
 *
 * 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
 */
package test.org.mandarax.reference;


import org.mandarax.kernel.ClauseSetChangeEvent;
import org.mandarax.kernel.Fact;
import org.mandarax.kernel.Predicate;

/**
 * Tests adding and removing a clause set change listener.
 * @see org.mandarax.kernel.ClauseSetChangeListener
 * @author <A href="http://www-ist.massey.ac.nz/JBDietrich" target="_top">Jens Dietrich</A>
 * @version 3.4 <7 March 05>
 * @since 1.1
 */
public class TestClauseSetEvents3 extends TestClauseSetEvents {

    /**
     * Constructor.
     */
    public TestClauseSetEvents3() {
        super ();
    }

    /**
     * Run the test.
     */
    public void testEvent() {
        EventHandler handler    = new EventHandler ();
        Fact         fact1      = Person.getFact ("isBrotherOf", "Lutz",
                                                  "Klaus");
        Fact         fact2      = Person.getFact ("isFatherOf", "Klaus",
                                                  "Jens");
        Predicate    predicate1 = fact1.getPredicate ();
        Predicate    predicate2 = fact2.getPredicate ();

        // add listener and change predicate, ckeck whhether listener receives event
        fact1.addClauseSetChangeListener (handler);
        fact1.setPredicate (predicate2);

        ClauseSetChangeEvent lastEvent =
            (ClauseSetChangeEvent) handler.handledEvents.peek ();
        boolean result = (handler.handledEvents.size () == 1)
                         && (lastEvent.getSource () == fact1)
                         && (lastEvent.getType () == ClauseSetChangeEvent.KEY_CHANGED);

        // now unregister listener and change predicate again .. the listener should not receive the event
        fact1.removeClauseSetChangeListener (handler);
        fact1.setPredicate (predicate1);
        assertTrue (result && (handler.handledEvents.size () == 1));
    }
}