Apache Lucene is a high-performance, full-featured text search engine library. Here's a simple example how to use Lucene for indexing and searching (using JUnit to check if the results are what we expect):
Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT); // Store the index in memory: Directory directory = new RAMDirectory(); // To store an index on disk, use this instead: //Directory directory = FSDirectory.open("/tmp/testindex"); IndexWriter iwriter = new IndexWriter(directory, analyzer, true, new IndexWriter.MaxFieldLength(25000)); Document doc = new Document(); String text = "This is the text to be indexed."; doc.add(new Field("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("fieldname", analyzer); Query query = parser.parse("text"); ScoreDoc[] hits = isearcher.search(query, null, 1000).scoreDocs; assertEquals(1, hits.length); // Iterate through the results: for (int i = 0; i < hits.length; i++) { Document hitDoc = isearcher.doc(hits[i].doc); assertEquals("This is the text to be indexed.", hitDoc.get("fieldname")); } isearcher.close(); directory.close();
