In contrast to a ResultSetExtractor, a RowCallbackHandler object is typically stateful: It keeps the result state within the object, to be available for later inspection. See RowCountCallbackHandler's javadoc for a usage example with JdbcTemplate.

The ResultReader subinterface allows to make a results list available in a uniform manner. JdbcTemplate's query methods will return the results list in that case, else returning null (-> result state is solely available from RowCallbackHandler object).

A convenient out-of-the-box implementation of RowCallbackHandler is the RowMapperResultReader adapter which delegates row mapping to a RowMapper. Note that a RowMapper object is typically stateless and thus reusable; just the RowMapperResultReader adapter is stateful.