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Lucene example source code file (OpenIndexTask.java)

This example Lucene source code file (OpenIndexTask.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

config, default_max_buffered, default_max_field_length, default_merge_pfactor, default_merge_pfactor, io, ioexception, ioexception, openindextask, openindextask, override, override, perfrundata, perftask, string

The Lucene OpenIndexTask.java source code

package org.apache.lucene.benchmark.byTask.tasks;

 * 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 org.apache.lucene.benchmark.byTask.PerfRunData;
import org.apache.lucene.benchmark.byTask.utils.Config;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexCommit;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.LogMergePolicy;
import org.apache.lucene.index.IndexWriter.MaxFieldLength;
import org.apache.lucene.index.IndexWriterConfig.OpenMode;
import java.io.IOException;

 * Open an index writer.
 * <br>Other side effects: index writer object in perfRunData is set.
 * <br>Relevant properties: merge.factor, max.buffered,
 * max.field.length, ram.flush.mb [default 0]</code>.
 * <p> Accepts a param specifying the commit point as
 * previously saved with CommitIndexTask.  If you specify
 * this, it rolls the index back to that commit on opening
 * the IndexWriter.
public class OpenIndexTask extends PerfTask {

  public static final int DEFAULT_MAX_BUFFERED = IndexWriterConfig.DEFAULT_MAX_BUFFERED_DOCS;
  public static final int DEFAULT_MAX_FIELD_LENGTH = MaxFieldLength.UNLIMITED.getLimit();
  public static final int DEFAULT_MERGE_PFACTOR = LogMergePolicy.DEFAULT_MERGE_FACTOR;
  public static final double DEFAULT_RAM_FLUSH_MB = (int) IndexWriterConfig.DEFAULT_RAM_BUFFER_SIZE_MB;
  private String commitUserData;

  public OpenIndexTask(PerfRunData runData) {

  public int doLogic() throws IOException {
    PerfRunData runData = getRunData();
    Config config = runData.getConfig();
    final IndexCommit ic;
    if (commitUserData != null) {
      ic = OpenReaderTask.findIndexCommit(runData.getDirectory(), commitUserData);
    } else {
      ic = null;
    final IndexWriter writer = CreateIndexTask.configureWriter(config, runData, OpenMode.APPEND, ic);
    return 1;

  public void setParams(String params) {
    if (params != null) {
      // specifies which commit point to open
      commitUserData = params;

  public boolean supportsParams() {
    return true;

Other Lucene examples (source code examples)

Here is a short list of links related to this Lucene OpenIndexTask.java source code file:

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