lucene - How to encrypt Lucene Index Files with password using LuceneTransform

Question

I am trying to create Lucene Index data from HTML files but its throwing an exception actually i want to encrypt my lucene index with password . Is there any other alternative?

     try{

       File outputdir=new File("path upto output directory");
       byte[] salt = new byte[16];
       String password = "lucenetransform";
       DataEncryptor enc = new DataEncryptor("AES/ECB/PKCS5Padding", password, salt,    128,false);
       DataDecryptor dec = new DataDecryptor(password, salt,false);

       IndexWriter indexwriter=new IndexWriter(new TransformedDirectory(FSDirectory.open(outputdir), enc, dec), new StandardAnalyzer(Version.LUCENE_36),true, IndexWriter.MaxFieldLength.LIMITED);


       }

       catch(Exception ex)
       {
         ex.printStackTrace();

       }