Callback interface used by JdbcTemplate's query methods. Implementations of this interface perform the actual work of extracting results, but don't need to worry about exception handling. SQLExceptions will be caught and handled correctly by the JdbcTemplate class.

This interface is mainly used within the JDBC framework. A RowCallbackHandler is usually a simpler choice for ResultSet processing, in particular a RowMapperResultReader in combination with a RowMapper.

Note: In contrast to a RowCallbackHandler, a ResultSetExtractor object is typically stateless and thus reusable, as long as it doesn't access stateful resources (like output streams when streaming LOB contents) or keep result state within the object.