ViewCountSorter.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.nutch.keymatch;

import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;

/**
 * <p>Implementation of KeyMatchFilter that sorts
 * keymatches based on KeyMatch view counts. It allows
 * simple rotation of matches (keymatches with lower view
 * counts are "prioritized").</p>
 */
public class ViewCountSorter extends AbstractFilter {
  
  public class ViewCountComparator implements Comparator {
    
    public int compare(Object o1, Object o2) {
      return ((KeyMatch)o1).viewCount-((KeyMatch)o2).viewCount;
    }
  }

  public KeyMatch[] filter(final List currentMatches, final Map context){
    Collections.sort(currentMatches, new ViewCountSorter.ViewCountComparator());
    return super.filter(currentMatches, context);
  }
}