content: package org.apache.lucene.search;
  
  /**
   * 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.
   */
  
  import java.io.IOException;
  
  import org.apache.lucene.index.IndexReader;
  
  /**
   * A {@link Collector} implementation which wraps another
   * {@link Collector} and makes sure only documents with
   * scores &gt; 0 are collected.
   */
  public class PositiveScoresOnlyCollector extends Collector {
  
    final private Collector c;
    private Scorer scorer;
    
    public PositiveScoresOnlyCollector(Collector c) {
      this.c = c;
    }
    
    @Override
    public void collect(int doc) throws IOException {
      if (scorer.score() > 0) {
        c.collect(doc);
      }
    }
  
    @Override
    public void setNextReader(IndexReader reader, int docBase) throws IOException {
      c.setNextReader(reader, docBase);
    }
  
    @Override
    public void setScorer(Scorer scorer) throws IOException {
      // Set a ScoreCachingWrappingScorer in case the wrapped Collector will call
      // score() also.
      this.scorer = new ScoreCachingWrappingScorer(scorer);
      c.setScorer(this.scorer);
    }
  
    @Override
    public boolean acceptsDocsOutOfOrder() {
      return c.acceptsDocsOutOfOrder();
    }
  
  }
  