How to use a field from Index to delete an entry?

[Anahita K]

I'm developing a Desktop Search Engine in VB 9 using Lucene.NET

I wish to delete and create a new entry for a file that is updated.

The Index stores complete file path and the last modified date.


doc.Add(New Field("path", filepath, Field.Store.YES,
Field.Index.UN_TOKENIZED))
doc.Add(New Field("modified", New FileInfo(filepath).LastWriteTime,
Field.Store.YES, Field.Index.UN_TOKENIZED))


I'm using the IndexReader to check if a file is present in the Index (to
avoid re-indexing the same files).


Dim reader As IndexReader = IndexReader.Open(indexFolder)

If reader.DocFreq(New Term("path", filepath)) = 0 Then
     addFile(filepath)
End If

reader.Close()


I have the following doubts:

   1. How do I use the value in the modified field to check if the Index
entry for a particular file is old? What function of IndexReader will allow
me to do this?
   2. How do I get the document number (docNum) for the function
deleteDocument()


Thank you.