hibernate - how to map a joined ResultSet to an object in java? -

i took example here map resultset object , , works great, realized problem can't map resultset join query. example have 2 tables, usr , vehicle. select query , join two.

public class usr {     public int id;     public vehicle vehicle; }  public class vehicle {     public int id;     public int year;     public string model;     public int user_id; } 

how can map resultset usr object? googled bit , found sqlresultsetmapping might solution, seems lot of work adopt hibernate, , i'm familiar pure java. example here, looks need rewrite query statements , put db structure in java.

is there other ways can map joined resultset object without mess on current code?

edited

the query this;

select * usr join vehicle on usr.id = vehicle.user_id; 

and want map usr object

lets break whole thing in new way. approach following kind of handy comes limitations. handles primitive types of field. classes having association other objects or tables in db foreign key mapping ? case having usr class in have vehicle associated relation.

rather doing mapping thing in generic way, write mapping logic in class reuse when necessary.

write rowmapper abstract class

public abstract class rowmapper<e> {  public list<e> processresultset(resultset rs) throws sqlexception {     list<e> objectlist = new arraylist<>();      while(rs.next()) {         objectlist.add(maprow(rs));     }      return objectlist; }  abstract e maprow(resultset rs) throws sqlexception; 

}

now write row mapping logic theusr class

public class usrmapper extends rowmapper<usr> {      @override     public state maprow(resultset rs, int rownum) throws sqlexception {          usr usr = new usr();         vehicle vehicle = new vehicle();          usr.setid(rs.getint("usr.id"));         vehicle.setid(rs.getint("vehicle.id"));         vehicle.setyear(rs.getint("vehicle.year"));         vehicle.setmodel(rs.getstring("vehicle.model"));          usr.setvehicle(vehicle);          return usr;     } } 

you can have implement rowmapper vehicle well. way go using this.

say got resultset following join query

select usr.id, vehicle.id, vehicle.year, vehicle.model usr join vehicle on usr.id = vehicle.user_id; 

now

usrmapper usrmapper = new usrmapper(); list<usr> usrlist = usrmapper.processresultset(resultset); 

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