On 01/23/2012 05:38 PM, Yair Zaslavsky wrote:

Hi all, I am refactoring now DiskImageDAODbFacadeImpl. As part of my work, I'm also defining there a Spring-JDBC mapper , similar to other ParameterizedRowMapper based mappers we have in code (i.e DbUserDAODbFacadeImpl has one) Looks like in our DAO getXXXX methods we instantiate these mapper objects (each method creates a new mapper object). Can anyone see a reason , in case a mapper object is stateless (and from what I see, they are) - why not to have a single instantiation per mapper type (i.e - Have a MapperUtils class, with static methods like MapperUtils.getDiskImageMapper() ? IMHO this can save us some unnecessary instanatiations and improve performance

+1 for the static suggestion. Since each mapper is used by a specific DAO impl class (and sometimes several mappers per DAO), but never shared between those DAOs, IMO they should be remained in the scope of the DAO which uses them and be defined inside the DAO class in a static block; static { mapper = new ParameterizedRowMapper<Entity>() { @Override public Entity mapRow(ResultSet rs, int rowNum){ ... } }; }

Yair _______________________________________________ Engine-devel mailing list Engine-devel@ovirt.org http://lists.ovirt.org/mailman/listinfo/engine-devel