Lucene example source code file (AssertingIndexSearcher.java)

This example Lucene source code file (AssertingIndexSearcher.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

assertingindexsearcher, assertingindexsearcher, explanation, illegalstateexception, indexsearcher, io, ioexception, ioexception, override, override, query, scorer, threading, threads, unmodifiableweight, weight, weight

The Lucene AssertingIndexSearcher.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.util.concurrent.ExecutorService;
import java.io.IOException;

import org.apache.lucene.index.IndexReader;

/** 
 * Helper class that adds some extra checks to ensure correct
 * usage of {@code IndexSearcher} and {@code Weight}.
 * TODO: Extend this by more checks, that's just a start.
 */
public class AssertingIndexSearcher extends IndexSearcher {
  public  AssertingIndexSearcher(IndexReader r) {
    super(r);
  }
  
  public  AssertingIndexSearcher(IndexReader r, ExecutorService ex) {
    super(r, ex);
  }
  
  // not anonymous because else not serializable (compare trunk)
  private static final class UnmodifiableWeight extends Weight {
    private final Weight w;
    
    UnmodifiableWeight(Weight w) {
      this.w = w;
    }
  
    @Override
    public Explanation explain(IndexReader reader, int doc) throws IOException {
      return w.explain(reader, doc);
    }

    @Override
    public Query getQuery() {
      return w.getQuery();
    }

    @Override
    public float getValue() {
      return w.getValue();
    }

    @Override
    public void normalize(float norm) {
      throw new IllegalStateException("Weight already normalized.");
    }

    @Override
    public Scorer scorer(IndexReader reader, boolean scoreDocsInOrder, boolean topScorer) throws IOException {
      return w.scorer(reader, scoreDocsInOrder, topScorer);
    }

    @Override
    public float sumOfSquaredWeights() throws IOException {
      throw new IllegalStateException("Weight already normalized.");
    }

    @Override
    public boolean scoresDocsOutOfOrder() {
      return w.scoresDocsOutOfOrder();
    }
  }
  
  /** Ensures, that the returned {@code Weight} is not normalized again, which may produce wrong scores. */
  @Override
  public Weight createNormalizedWeight(Query query) throws IOException {
    final Weight w = super.createNormalizedWeight(query);
    return new UnmodifiableWeight(w);
  }
}