Lucene Examples for The Rich Web Experience 2013

LuceneExamples.java

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.analysis.TokenStream;
import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.codecs.simpletext.SimpleTextCodec;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.queryparser.classic.ParseException;
import org.apache.lucene.queryparser.classic.QueryParser;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.store.RAMDirectory;
import org.apache.lucene.util.Version;

import java.io.File;
import java.io.IOException;


public class LuceneExamples {

  public static void main(String[] args) throws IOException, ParseException {

    // Adapted from http://lucene.apache.org/core/4_6_0/core/overview-summary.html#overview_description
    Analyzer analyzer = new StandardAnalyzer(Version.LUCENE_CURRENT);

    Directory directory = new RAMDirectory(); // FSDirectory.open(new File("/path/to/index")); // use FSDirectory to see the SimpleText output


    IndexWriterConfig config = new IndexWriterConfig(Version.LUCENE_CURRENT, analyzer);
    config.setCodec(new SimpleTextCodec());
    config.setUseCompoundFile(false);
    config.setOpenMode(IndexWriterConfig.OpenMode.CREATE);
    IndexWriter writer = new IndexWriter(directory, config);
    Document doc = new Document();
    String text = "The Rich Web Experience 2013: Lucene Examples";
    doc.add(new Field("title", text, TextField.TYPE_STORED));
    writer.addDocument(doc);
    writer.close();

    // Now search the index:
    DirectoryReader reader = DirectoryReader.open(directory);
    IndexSearcher searcher = new IndexSearcher(reader);
    // Parse a simple query that searches for "text":
    QueryParser parser = new QueryParser(Version.LUCENE_CURRENT, "default_field", analyzer);
    Query query = parser.parse("title:(experience lucene)");
    System.out.println("query (" + query.getClass() + ") = " + query);
    ScoreDoc[] hits = searcher.search(query, null, 1000).scoreDocs;
    System.out.println("hits = " + hits.length);
    // Iterate through the results:
    for (ScoreDoc hit : hits) {
      Document hitDoc = searcher.doc(hit.doc);
      System.out.println("hitDoc.get(\"title\") = " + hitDoc.get("title"));

      Explanation explanation = searcher.explain(query, hit.doc);
      System.out.println(explanation.toString());
    }
    reader.close();
    directory.close();




    TokenStream ts = analyzer.tokenStream("field_name", "some text goes here");
    //CharTermAttribute termAttr = ts.addAttribute(CharTermAttribute.class);

    try {
      ts.reset();
      while (ts.incrementToken()) {
        System.out.println("token: " + ts.reflectAsString(false));
      }
      ts.end();   // Perform end-of-stream operations, e.g. set the final offset.
    } finally {
      ts.close(); // Release resources associated with this stream.
    }

  }

}