Lucene example source code file (TestDocBoost.java)

This example Lucene source code file (TestDocBoost.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Lucene tags/keywords

document, document, fieldable, indexreader, io, ioexception, ioexception, lucenetestcase, override, override, randomindexwriter, randomindexwriter, scorer, term, termquery

The Lucene TestDocBoost.java source code

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.analysis.MockAnalyzer;
import org.apache.lucene.document.*;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.RandomIndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.LuceneTestCase;

/** Document boost unit test.
 *
 *
 * @version $Revision: 1099728 $
 */
public class TestDocBoost extends LuceneTestCase {

  public void testDocBoost() throws Exception {
    Directory store = newDirectory();
    RandomIndexWriter writer = new RandomIndexWriter(random, store, newIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(random)).setMergePolicy(newLogMergePolicy()));

    Fieldable f1 = newField("field", "word", Field.Store.YES, Field.Index.ANALYZED);
    Fieldable f2 = newField("field", "word", Field.Store.YES, Field.Index.ANALYZED);
    f2.setBoost(2.0f);

    Document d1 = new Document();
    Document d2 = new Document();
    Document d3 = new Document();
    Document d4 = new Document();
    d3.setBoost(3.0f);
    d4.setBoost(2.0f);

    d1.add(f1);                                 // boost = 1
    d2.add(f2);                                 // boost = 2
    d3.add(f1);                                 // boost = 3
    d4.add(f2);                                 // boost = 4

    writer.addDocument(d1);
    writer.addDocument(d2);
    writer.addDocument(d3);
    writer.addDocument(d4);

    IndexReader reader = writer.getReader();
    writer.close();

    final float[] scores = new float[4];

    newSearcher(reader).search
      (new TermQuery(new Term("field", "word")),
       new Collector() {
         private int base = 0;
         private Scorer scorer;
         @Override
         public void setScorer(Scorer scorer) throws IOException {
          this.scorer = scorer;
         }
         @Override
         public final void collect(int doc) throws IOException {
           scores[doc + base] = scorer.score();
         }
         @Override
         public void setNextReader(IndexReader reader, int docBase) {
           base = docBase;
         }
         @Override
         public boolean acceptsDocsOutOfOrder() {
           return true;
         }
       });

    float lastScore = 0.0f;

    for (int i = 0; i < 4; i++) {
      assertTrue(scores[i] > lastScore);
      lastScore = scores[i];
    }
    
    reader.close();
    store.close();
  }
}