2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
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14 * See the License for the specific language governing permissions and
15 * limitations under the License.
17 package org.apache.lucene.benchmark.quality.utils;
19 import java.io.IOException;
21 import org.apache.lucene.document.FieldSelector;
22 import org.apache.lucene.document.FieldSelectorResult;
23 import org.apache.lucene.search.IndexSearcher;
26 * Utility: extract doc names from an index
28 public class DocNameExtractor {
30 private FieldSelector fldSel;
31 private String docNameField;
34 * Constructor for DocNameExtractor.
35 * @param docNameField name of the stored field containing the doc name.
37 public DocNameExtractor (final String docNameField) {
38 this.docNameField = docNameField;
39 fldSel = new FieldSelector() {
40 public FieldSelectorResult accept(String fieldName) {
41 return fieldName.equals(docNameField) ?
42 FieldSelectorResult.LOAD_AND_BREAK :
43 FieldSelectorResult.NO_LOAD;
49 * Extract the name of the input doc from the index.
50 * @param searcher access to the index.
51 * @param docid ID of doc whose name is needed.
52 * @return the name of the input doc as extracted from the index.
53 * @throws IOException if cannot extract the doc name from the index.
55 public String docName(IndexSearcher searcher, int docid) throws IOException {
56 return searcher.doc(docid,fldSel).get(docNameField);