lia.searching.NearRealTime.java Source code

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Here is the source code for lia.searching.NearRealTime.java

Source

package lia.searching;

/**
 * Copyright Manning Publications Co.
 *
 * Licensed 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 lan      
*/

import junit.framework.TestCase;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.LongField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.Version;

// From chapter 3
public class NearRealTime extends TestCase {
    public void testNearRealTime() throws Exception {
        Directory dir = new RAMDirectory();
        IndexWriterConfig iwc = new IndexWriterConfig(Version.LUCENE_46, new StandardAnalyzer(Version.LUCENE_45));
        IndexWriter writer = new IndexWriter(dir, iwc);
        for (int i = 0; i < 10; i++) {
            Document doc = new Document();
            doc.add(new LongField("id", i, Field.Store.NO));
            doc.add(new TextField("text", "aaa", Field.Store.NO));
            writer.addDocument(doc);
        }
        DirectoryReader reader = DirectoryReader.open(writer, true); // #1
        IndexSearcher searcher = new IndexSearcher(reader); // #A

        Query query = new TermQuery(new Term("text", "aaa"));
        TopDocs docs = searcher.search(query, 1);
        assertEquals(10, docs.totalHits); // #B

        writer.deleteDocuments(new Term("id", "7")); // #2
        IndexReader newReader = writer.getReader();

        if (r2 != null) {
            reader.close();
            reader = r2;
        } else {
            // recreate
            reader.close();
            reader = DirectoryReader.open(dir);
        }
        searcher = new IndexSearcher(reader); // #A
        docs = searcher.search(query, 10);
        assertEquals(9, docs.totalHits);
        /*    Document doc = new Document();                           // #3
            doc.add(new LongField("id",                                  // #3
                  11,                                  // #3
                  Field.Store.NO));   // #3
            doc.add(new TextField("text",                                // #3
                  "bbb",                                 // #3
                  Field.Store.NO));                // #3
            writer.addDocument(doc);                                 // #3
        */

        /*    searcher = new IndexSearcher(DirectoryReader.openIfChanged(reader, writer, true));              
            
            TopDocs hits = searcher.search(query, 10);               // #7
            assertEquals(9, hits.totalHits);                         // #7
        */
        query = new TermQuery(new Term("text", "bbb")); // #8
        TopDocs hits = searcher.search(query, 1); // #8
        assertEquals(1, hits.totalHits); // #8

        reader.close();
        writer.close();
    }
}

/*
  #1 Create near-real-time reader
  #A Wrap reader in IndexSearcher
  #B Search returns 10 hits
  #2 Delete 1 document
  #3 Add 1 document
  #4 Reopen reader
  #5 Confirm reader is new
  #6 Close old reader
  #7 Verify 9 hits now
  #8 Confirm new document matched
*/

/*
#1 IndexWriter returns a reader that's able to search all previously committed changes to the index, plus any uncommitted changes.  The returned reader is always readOnly.
#2,#3 We make changes to the index, but do not commit them.
#4,#5,#6 Ask the reader to reopen.  Note that this simply re-calls writer.getReader again under the hood.  Because we made changes, the newReader will be different from the old one so we must close the old one.
#7, #8 The changes made with the writer are reflected in new searches.
*/