gistfile1.java

package de.samedi.searcher;


import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;

import java.io.IOException;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.junit.Test;

public class LuceneReload {

	private IndexSearcher searcher1;
	private IndexSearcher searcher2;
	private FSDirectory directory1, directory2;


	@Test
	public void testReload() throws Exception {
		String home = System.getProperty("user.home");


		this.directory1 = FSDirectory.getDirectory(home + "/testIndex");
		this.directory2 = FSDirectory.getDirectory(home + "/testIndex");

		// initialize (empty / create the index)
		new IndexWriter(this.directory1, new StandardAnalyzer(), true, IndexWriter.MaxFieldLength.LIMITED);


		// assert that we're empty
		assertFound(getSearcher1(), "test", 0);
		assertFound(getSearcher2(), "test", 0);

		add(this.directory1, "test");
		assertFound(getSearcher1(), "test", 1);
		assertFound(getSearcher2(), "test", 1);

		add(this.directory2, "foobar");
		assertFound(getSearcher1(), "foobar", 1);
		assertFound(getSearcher2(), "foobar", 1);
		assertFound(getSearcher1(), "test", 1);
		assertFound(getSearcher2(), "test", 1);
	}

	public void assertFound(IndexSearcher searcher, String q, int expected_number) {
		try {
			QueryParser parser = new QueryParser("name", new StandardAnalyzer());
			Query query = parser.parse(q);
			TopDocs t = searcher.search(query, null, 50);
			assertEquals(expected_number, t.totalHits);
		} catch (Exception e) {
			e.printStackTrace();
			fail();
		}

	}

	public IndexSearcher getSearcher1() throws CorruptIndexException, IOException {
		if (this.searcher1 == null) {
			this.searcher1 = new IndexSearcher(IndexReader.open(this.directory1));
		} else {
			IndexReader new_reader, old_reader;

			old_reader = this.searcher1.getIndexReader();
			new_reader = old_reader.reopen();
			//			new_reader = IndexReader.open(this.directory1);

			if (new_reader != old_reader) {
				System.err.println("index1 changed");
				this.searcher1.close();
				old_reader.close();
				this.searcher1 = new IndexSearcher(new_reader);
			}
		}

		return this.searcher1;
	}

	public IndexSearcher getSearcher2() throws CorruptIndexException, IOException {
		if (this.searcher2 == null) {
			this.searcher2 = new IndexSearcher(this.directory2);
		} else {
			IndexReader new_reader, old_reader;

			old_reader = this.searcher2.getIndexReader();
			new_reader = old_reader.reopen();

			if (new_reader != old_reader) {
				System.err.println("index2 changed");
				this.searcher2.close();
				old_reader.close();
				this.searcher2 = new IndexSearcher(new_reader);
			}
		}

		return this.searcher2;
	}

	public void add(Directory directory, String name) throws CorruptIndexException, IOException {
		IndexWriter w = new IndexWriter(directory, new StandardAnalyzer(), false, IndexWriter.MaxFieldLength.LIMITED);

		Document d = new Document();
		d.add(new Field("name", name, Field.Store.YES, Field.Index.ANALYZED));
		w.addDocument(d);
		w.commit();
		w.close();
	}


}