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Lucene example source code file (DocNameExtractor.java)

This example Lucene source code file (DocNameExtractor.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

docnameextractor, docnameextractor, fieldselector, fieldselector, fieldselectorresult, io, ioexception, ioexception, string, string

The Lucene DocNameExtractor.java source code

 * 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,
 * See the License for the specific language governing permissions and
 * limitations under the License.
package org.apache.lucene.benchmark.quality.utils;

import java.io.IOException;

import org.apache.lucene.document.FieldSelector;
import org.apache.lucene.document.FieldSelectorResult;
import org.apache.lucene.search.Searcher;

 * Utility: extract doc names from an index
public class DocNameExtractor {

  private FieldSelector fldSel;
  private String docNameField;
   * Constructor for DocNameExtractor.
   * @param docNameField name of the stored field containing the doc name. 
  public DocNameExtractor (final String docNameField) {
    this.docNameField = docNameField;
    fldSel = new FieldSelector() {
      public FieldSelectorResult accept(String fieldName) {
        return fieldName.equals(docNameField) ? 
            FieldSelectorResult.LOAD_AND_BREAK :
   * Extract the name of the input doc from the index.
   * @param searcher access to the index.
   * @param docid ID of doc whose name is needed.
   * @return the name of the input doc as extracted from the index.
   * @throws IOException if cannot extract the doc name from the index.
  public String docName(Searcher searcher, int docid) throws IOException {
    return searcher.doc(docid,fldSel).get(docNameField);

Other Lucene examples (source code examples)

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