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Lucene example source code file (TestLazyBug.java)

This example Lucene source code file (TestLazyBug.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

directory, directory, document, document, exception, exception, fieldselector, indexwriter, logmergepolicy, num_docs, num_docs-1, selector, string, string, util

The Lucene TestLazyBug.java source code

package org.apache.lucene.index;

 * 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.

import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.FieldSelector;
import org.apache.lucene.document.FieldSelectorResult;
import org.apache.lucene.document.Fieldable;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.LuceneTestCase;
import org.junit.AfterClass;
import org.junit.BeforeClass;

 * Test demonstrating EOF bug on the last field of the last doc 
 * if other docs have allready been accessed.
public class TestLazyBug extends LuceneTestCase {

  public static int NUM_DOCS = TEST_NIGHTLY ? 500 : 50;
  public static int NUM_FIELDS = TEST_NIGHTLY ? 100 : 10;

  private static String[] data = new String[] {
    "is the time",
    "for all good men",
    "to come to the aid",
    "of their country!",
    "this string contains big chars:{\u0111 \u0222 \u0333 \u1111 \u2222 \u3333}",
    "this string is a bigger string, mary had a little lamb, little lamb, little lamb!"

  private static Set<String> dataset = new HashSet(Arrays.asList(data));
  private static String MAGIC_FIELD = "f"+(NUM_FIELDS/3);
  private static Directory directory;
  public static void beforeClass() throws Exception {
    directory = makeIndex();
  public static void afterClass() throws Exception {
    directory = null;

  private static FieldSelector SELECTOR = new FieldSelector() {
      public FieldSelectorResult accept(String f) {
        if (f.equals(MAGIC_FIELD)) {
          return FieldSelectorResult.LOAD;
        return FieldSelectorResult.LAZY_LOAD;

  private static Directory makeIndex() throws Exception {
    Directory dir = newDirectory();
    try {
      IndexWriter writer = new IndexWriter(dir, newIndexWriterConfig(
                                                                     TEST_VERSION_CURRENT, new MockAnalyzer(random)).setMergePolicy(newLogMergePolicy()));
      LogMergePolicy lmp = (LogMergePolicy) writer.getConfig().getMergePolicy();

      for (int d = 1; d <= NUM_DOCS; d++) {
        Document doc = new Document();
        for (int f = 1; f <= NUM_FIELDS; f++ ) {
                            data[f % data.length]
                            + '#' + data[random.nextInt(data.length)],
    } catch (Exception e) {
      throw new RuntimeException(e);
    return dir;
  public void doTest(int[] docs) throws Exception {
    IndexReader reader = IndexReader.open(directory, true);
    for (int i = 0; i < docs.length; i++) {
      Document d = reader.document(docs[i], SELECTOR);
      List<Fieldable> fields = d.getFields();
      for (Iterator<Fieldable> fi = fields.iterator(); fi.hasNext(); ) {
        Fieldable f=null;
        try {
          f =  fi.next();
          String fname = f.name();
          String fval = f.stringValue();
          assertNotNull(docs[i]+" FIELD: "+fname, fval);
          String[] vals = fval.split("#");
          if (!dataset.contains(vals[0]) || !dataset.contains(vals[1])) {        
        } catch (Exception e) {
          throw new Exception(docs[i]+" WTF: "+f.name(), e);

  public void testLazyWorks() throws Exception {
    doTest(new int[] { NUM_DOCS-1 });
  public void testLazyAlsoWorks() throws Exception {
    doTest(new int[] { NUM_DOCS-1, NUM_DOCS/2 });

  public void testLazyBroken() throws Exception {
    doTest(new int[] { NUM_DOCS/2, NUM_DOCS-1 });


Other Lucene examples (source code examples)

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