Lucene 2.4.0 - Hello World application to play around with indexing / searching capabilities of Lucene. The original code is attributed to Lucene tutorial mentioned
here.
Some of the API in the code like Hits have been deprecated that creates costly Document objects. The revised code, after addressing compilation warnings is shown herewith.
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.IndexWriter;
import org.apache.lucene.index.IndexWriter.MaxFieldLength;
import org.apache.lucene.queryParser.ParseException;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;
public class HelloLucene {
public static void main(String[] args) throws IOException, ParseException {
// 1. create the index
Directory index = new RAMDirectory();
IndexWriter w = new IndexWriter(index, new StandardAnalyzer(), true, new MaxFieldLength(25000));
addDoc(w, "Lucene in Action");
addDoc(w, "Lucene for Dummies");
addDoc(w, "Managing Gigabytes");
addDoc(w, "The Art of Computer Science");
w.close();
// 2. query
String querystr = args.length > 0 ? args[0] : "lucene";
Query q = new QueryParser("title", new StandardAnalyzer()).parse(querystr);
// 3. search
IndexSearcher s = new IndexSearcher(index);
TopDocs docs = s.search(q, null, 100);
// 4. display results
System.out.println("Found " + docs.totalHits + " hits.");
ScoreDoc [] hits = docs.scoreDocs;
int i = 0;
for(ScoreDoc scoreDoc : hits) {
System
.out.println((i + 1) + ". " + s.doc(scoreDoc.doc) );
++i;
}
s.close();
}
private static void addDoc(IndexWriter w, String value) throws IOException {
Document doc = new Document();
doc.add(new Field("title", value, Field.Store.YES, Field.Index.ANALYZED));
w.addDocument(doc);
}
}
