Hello,
some major changes:
check out the code on github.

1. Everybody should move and adapt the isValid method, so that it is
used as following:
             ex:    if ( cemetery.isValid() ) {...}
             so basically you verify the data inside the object
(everybody, use the abstract method derived from model.Data (this is an
interface for the objects))
2. We only gona have the subrepository objects held in the
mainRepository class. nothing else.
            accessing the repos will be done through the Repository
class like:
                             rep.cemeteryRepository.*method to call* ()
---called from controller or whatever
3. We're not gona handle sql queries at the repositories, instead:
             call on DataBase.getInstance() -->save this obeject as
DataBase object
             then use it as:        
                            db.addData(Cemetery g, DataBase.CEMETERY);
4. Go check ot these classes and the examples and correct your tasks
accordingly:
                    model.Data
                    repository.Repository
                    repository.DataBase
                    



Check out the Cemetery class (and Repository) for an example on
isValid() 
and how everything should come together

for People sub classes isValid example, check out People & Complainer
classes.

---make sure you have mysql connector added as external lib
(I also added the newest version jar in libs/)