All field of a full text index in Lucene have to be represented as Strings. Ones Java properties have to be indexed in a String form. For most of your properties, Hibernate Search™ does the translation job for you thanks to a built-in set of bridges. In some cases, though you need a fine grain control over the translation process.
[1] Using a Range query is debattable and has drawbacks, an alternative approach is to use a Filter query which will filter the result query to the appropriate range.
Hibernate Search™ will support a padding mechanism