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Lucene example source code file (TestDemo.java)

This example Lucene source code file (TestDemo.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, indexsearcher, indexsearcher, io, ioexception, lucenetestcase, mockanalyzer, query, queryparser, queryparser, randomindexwriter, randomindexwriter, this, topdocs

The Lucene TestDemo.java source code

package org.apache.lucene;

/**
 * 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.io.IOException;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.MockAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.RandomIndexWriter;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.LuceneTestCase;

/**
 * A very simple demo used in the API documentation (src/java/overview.html).
 *
 * Please try to keep src/java/overview.html up-to-date when making changes
 * to this class.
 */
public class TestDemo extends LuceneTestCase {

  public void testDemo() throws IOException, ParseException {
    Analyzer analyzer = new MockAnalyzer(random);

    // Store the index in memory:
    Directory directory = newDirectory();
    // To store an index on disk, use this instead:
    //Directory directory = FSDirectory.open("/tmp/testindex");
    RandomIndexWriter iwriter = new RandomIndexWriter(random, directory, analyzer);
    iwriter.w.setInfoStream(VERBOSE ? System.out : null);
    Document doc = new Document();
    String text = "This is the text to be indexed.";
    doc.add(newField("fieldname", text, Field.Store.YES,
        Field.Index.ANALYZED));
    iwriter.addDocument(doc);
    iwriter.close();
    
    // Now search the index:
    IndexSearcher isearcher = new IndexSearcher(directory, true); // read-only=true
    // Parse a simple query that searches for "text":
    QueryParser parser = new QueryParser(TEST_VERSION_CURRENT, "fieldname", analyzer);
    Query query = parser.parse("text");
    TopDocs hits = isearcher.search(query, null, 1);
    assertEquals(1, hits.totalHits);
    // Iterate through the results:
    for (int i = 0; i < hits.scoreDocs.length; i++) {
      Document hitDoc = isearcher.doc(hits.scoreDocs[i].doc);
      assertEquals("This is the text to be indexed.", hitDoc.get("fieldname"));
    }

    // Test simple phrase query
    query = parser.parse("\"to be\"");
    assertEquals(1, isearcher.search(query, null, 1).totalHits);

    isearcher.close();
    directory.close();
  }
}

Other Lucene examples (source code examples)

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

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