TDB + Indexing issue.

Hi,
I have loaded large N-Triple data into tdb by using tdbloader.
This is a command that I have used :
C:\apache-jena-2.11.1\bat>tdbloader --loc tdblocation xyz.nt

After that I have written java code for text based search.

public static void main(String[] args) {
Dataset ds = null;
String directory = "TDB";
Dataset ds1 = TDBFactory.createDataset(directory);
try {
EntityDefinition entDef = new EntityDefinition("uri",
"property", RDFS.label);
Directory dir = FSDirectory.open(new File("LUCENE"));

ds = TextDatasetFactory.createLucene(ds1, dir, entDef);

String queryString = "PREFIX rdf: <
http://www.w3.org/1999/02/22-rdf-
syntax-ns#> \n"
+ " PREFIX text: <http://jena.apache.org/text#> \n"
+ " Select * where {?s text:query \"xyz\" . \n"
+ " }";

ds.begin(ReadWrite.READ);

Query q = QueryFactory.create(queryString);
QueryExecution qexec = QueryExecutionFactory.create(q, ds);
QueryExecUtils.executeQuery(q, qexec);
ds.end();

} catch (Exception e) {
System.out.println(e.toString());

The above code doesn't give any result.
And after the execution of this line ( ds =
TextDatasetFactory.createLucene(ds1, dir, entDef);) I thought that it will
create the index, but I can't see anything in LUCENE folder.

Therefore I think that it doesn't have the index data therefore text:query
is not working.

If I replace text:query with ?p , it shows some result.
But I want to do text based search on the dataset created from TDB.

Does any one know how to make it work??
Any suggestions?