I have these two classes (Getter/Setter/Constructor omitted):

public class Company { private String name; private String adress; private List<Employee> employees; private Uuid id; } public class Employee { private String name; private int age; private Uuid id; } 

The two entities and their relationship are modeled in a relational database using the tables COMPANY, EMPLOYEE and EMPLOYMENT.

Now i want to write the DAO classes to manage persistance of the two entities and their relationship. The easy way would be making a DAO for each one and have the CompanyDao use the EmployeeDao internally. But according to some Stackoverflow answers i read this is a design smell and should be refactored into service methods which use the DAOs without them having to depend on each other.

This is the way i would implement this service method:

public class DBService { public DBService(CompanyDao companyDao, EmployeeDao employeeDao, EmploymentDao employmentDao) { ... } public Company findCompany(Uuid companyId) { Company company = companyDao.find(companyId); List<Uuid> employeeIds = employmentDao.findEmployeeIds(company.getId()); for(Uuid employeeId : employeeIds) { company.addEmployee(employeeDao.find(employeeId)); } } } 

Is this a good way to do this? Or should the EmployeeDao have a findByCompany(Uuid companyId) method?

Info: I already asked a smiliar question on Stackoverflow, but the only answers i got was "Use an ORM tool". I know that something like Hibernate would manage all of the persistance for me, but I would like to know how to do this by hand.

I have these two classes (Getter/Setter/Constructor omitted):

public class Company { private String name; private String adress; private List<Employee> employees; private Uuid id; } public class Employee { private String name; private int age; private Uuid id; } 

The two entities and their relationship are modeled in a relational database using the tables COMPANY, EMPLOYEE and EMPLOYMENT.

Now I want to write the DAO classes to manage persistance of the two entities and their relationship. The easy way would be making a DAO for each one and have the CompanyDao use the EmployeeDao internally. But according to some Stackoverflow answers I've read, this is a design smell and should be refactored into service methods which use the DAOs without them having to depend on each other.

This is the way I would implement this service method:

public class DBService { public DBService(CompanyDao companyDao, EmployeeDao employeeDao, EmploymentDao employmentDao) { ... } public Company findCompany(Uuid companyId) { Company company = companyDao.find(companyId); List<Uuid> employeeIds = employmentDao.findEmployeeIds(company.getId()); for(Uuid employeeId : employeeIds) { company.addEmployee(employeeDao.find(employeeId)); } } } 

Is this a good way to do this? Or should the EmployeeDao have a findByCompany(Uuid companyId) method?

Info: I already asked a smiliar question on Stackoverflow, but the only answers I got was "Use an ORM tool". I know that something like Hibernate would manage all of the persistance for me, but I would like to know how to do this by hand.