title: lucene updation problem
body: <p>i am using this function to update the index ..</p>
  
  <pre><code>    private static void insert_index(String url)throws Exception
  {
   System.out.println(url);
      IndexWriter writer = new IndexWriter(
              FSDirectory.open(new File(INDEX_DIR)),
              new StandardAnalyzer(Version.LUCENE_CURRENT),
              true,
              IndexWriter.MaxFieldLength.UNLIMITED);
      Document doc;
      String field;
      String text;
  
  
      doc = new Document();
  
      field = "url";
      text = url;
      doc.add(new Field(field, text, Field.Store.YES, Field.Index.ANALYZED));
  
  
  
      field = "tags";
      text = "url";
      doc.add(new Field(field, text, Field.Store.YES, Field.Index.ANALYZED));
  
      writer.addDocument(doc);
      writer.commit();
      writer.close();
  
  
  
  }
  </code></pre>
  
  <p>it index more urls and if i search the field with url it shows only the last indexed url....</p>