Lucene example source code file (TestWindowsMMap.java)

This example Lucene source code file (TestWindowsMMap.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

document, document, exception, file, file, indexsearcher, indexwriter, io, mmapdirectory, mockanalyzer, override, string, string, stringbuilder, stringbuilder, util

The Lucene TestWindowsMMap.java source code

package org.apache.lucene.store;

/**
 * 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.Collections;
import java.io.File;

import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.util._TestUtil;

import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.IndexWriterConfig.OpenMode;
import org.apache.lucene.search.IndexSearcher;

public class TestWindowsMMap extends LuceneTestCase {
  
  private final static String alphabet = "abcdefghijklmnopqrstuvwzyz";
  
  @Override
  public void setUp() throws Exception {
    super.setUp();
  }
  
  private String randomToken() {
    int tl = 1 + random.nextInt(7);
    StringBuilder sb = new StringBuilder();
    for(int cx = 0; cx < tl; cx ++) {
      int c = random.nextInt(25);
      sb.append(alphabet.substring(c, c+1));
    }
    return sb.toString();
  }
  
  private String randomField() {
    int fl = 1 + random.nextInt(3);
    StringBuilder fb = new StringBuilder();
    for(int fx = 0; fx < fl; fx ++) {
      fb.append(randomToken());
      fb.append(" ");
    }
    return fb.toString();
  }
  
  private final static String storePathname = 
   _TestUtil.getTempDir("testLuceneMmap").getAbsolutePath();

  public void testMmapIndex() throws Exception {
    // sometimes the directory is not cleaned by rmDir, because on Windows it
    // may take some time until the files are finally dereferenced. So clean the
    // directory up front, or otherwise new IndexWriter will fail.
    File dirPath = new File(storePathname);
    rmDir(dirPath);
    MMapDirectory dir = new MMapDirectory(dirPath, null);
    
    // plan to add a set of useful stopwords, consider changing some of the
    // interior filters.
    MockAnalyzer analyzer = new MockAnalyzer(random);
    // TODO: something about lock timeouts and leftover locks.
    IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(
        TEST_VERSION_CURRENT, analyzer)
        .setOpenMode(OpenMode.CREATE));
    writer.commit();
    IndexSearcher searcher = new IndexSearcher(dir, true);
    
    int num = atLeast(1000);
    for (int dx = 0; dx < num; dx++) {
      String f = randomField();
      Document doc = new Document();
      doc.add(newField("data", f, Field.Store.YES, Field.Index.ANALYZED));	
      writer.addDocument(doc);
    }
    
    searcher.close();
    writer.close();
    rmDir(dirPath);
  }

  private void rmDir(File dir) {
    if (!dir.exists()) {
      return;
    }
    for (File file : dir.listFiles()) {
      file.delete();
    }
    dir.delete();
  }
}