/**
* Copyright 2005 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.conflict;
import org.drools.spi.Activation;
import org.drools.spi.ConflictResolver;
/**
* <code>ConflictResolver</code> that uses the salience of rules to resolve
* conflict.
*
* @see #getInstance
* @see org.drools.rule.Rule#getSalience
*
* @author <a href="mailto:bob@werken.com">bob mcwhirter </a>
* @author <a href="mailto:simon@redhillconsulting.com.au">Simon Harris </a>
*
* @version $Id: SalienceConflictResolver.java,v 1.3 2004/06/25 02:46:39
* mproctor Exp $
*/
public class SalienceConflictResolver extends AbstractConflictResolver {
// ----------------------------------------------------------------------
// Class members
// ----------------------------------------------------------------------
/**
*
*/
private static final long serialVersionUID = 510l;
/** Singleton instance. */
private static final SalienceConflictResolver INSTANCE = new SalienceConflictResolver();
// ----------------------------------------------------------------------
// Class methods
// ----------------------------------------------------------------------
/**
* Retrieve the singleton instance.
*
* @return The singleton instance.
*/
public static ConflictResolver getInstance() {
return SalienceConflictResolver.INSTANCE;
}
// ----------------------------------------------------------------------
// Constructors
// ----------------------------------------------------------------------
/**
* Construct.
*/
public SalienceConflictResolver() {
// intentionally left blank
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
/**
* @see ConflictResolver
*/
public int compare(final Activation lhs,
final Activation rhs) {
final int s1 = lhs.getSalience();
final int s2 = rhs.getSalience();
if ( s1 > s2 ) {
return -1;
} else if ( s1 < s2 ) {
return 1;
} else {
return 0;
}
}
}