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.queryParser.QueryParser;
import org.apache.lucene.queryParser.ParseException;

import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Searcher;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopDocs;

import org.apache.lucene.store.FSDirectory;

public class HelloLucene {
    public static void buildIndex() throws IOException {
        IndexWriter indexWriter
            = new IndexWriter(FSDirectory.getDirectory("helloLuceneIndex"),
                              new StandardAnalyzer(),
                              IndexWriter.MaxFieldLength.LIMITED);
        String[] texts = new String[] {  "hello world",
                                         "hello sailor",
                                         "goodnight moon" };
        for (String text : texts) {
            Document doc = new Document();
            doc.add(new Field("text",text,Field.Store.YES,Field.Index.ANALYZED));
            indexWriter.addDocument(doc);
        }
        indexWriter.close();
    }
        
    public static void searchIndex(String[] queryStrings) 
        throws IOException, ParseException {
        Searcher searcher 
            = new IndexSearcher(FSDirectory.getDirectory("helloLuceneIndex"));
        QueryParser parser = new QueryParser("text",new StandardAnalyzer());
        for (String queryString : queryStrings) {
            System.out.println("\nsearching for: " + queryString);
            Query query = parser.parse(queryString);
            TopDocs results = searcher.search(query,10);
            System.out.println("total hits: " + results.totalHits);
            ScoreDoc[] hits = results.scoreDocs;
            for (ScoreDoc hit : hits) {
                Document doc = searcher.doc(hit.doc);
                System.out.printf("%5.3f %s\n",
                                  hit.score, doc.get("text"));
            }
        }
        searcher.close();
    }

    public static void main(String[] args) throws Exception {
        buildIndex();
        System.out.println("built index");
        searchIndex(args);
        System.out.println("\nall done");
    }

}