what is BUSINESS DELIGATE PATTERN,DAO,VO,DTO?

Answer Posted / kathiravan j

Let's say I have three tables:

Employee (contains employee_id, employee_name, and dept_id)
Department (contains dept_id, dept_name, loc_id)
Location (contains loc_id, location_name)

How deep do your classes go to replicate the data?
Do you do this...

public class Employee {
private int id;
private String name;
private int deptId; // just the id

// .. implementation details
}

or do you do this

public class Employee {
private int id;
private String name;
private Department dept; // all of the data

// .. implementation details
}

and so on and so on. Class Department has the same type of
problem. Does it hold just the id for location or a
variable class Location?

Should DAOs just fill in the id (keys) so it is up to the
application using the DAOs to get the Employee class, then
the Department class, and the the Location class like:

Employee emp = EmployeDAO.getEmployee(1);
Department dept = DepartmentDAO.getDepartment(emp.getDeptId
());
Location loc = LocationDAO.getLocation(dept.getLocId());
System.out.println(emp.getEmpName() + " works in " +
loc.getLocationName());

or

Employee emp = EmployeDAO.getEmployee(1);
System.out.println(emp.getEmpName() + " works in " +
emp.getDept().getLoc().getLocationName());

Now this is just a simple example, but where do you draw
the line? It's possible to go on and on and on and cycle
back to employee... Taking another approach to the same
question...Say I have an employee_type table having values
of fulltime, parttime, etc. Whay do you store in the
employee class now? Just a String with the value of the
type or the key to the employee_type table? Is it
application dependent?

Is This Answer Correct ?    10 Yes 2 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Can we use struts and spring together?

618


What is the purpose of @requiredstringvalidator?

640


How does one create an action in struts 2?

611


List some bundled validators?

656


What are the classes used in struts?

723






What is the use of struts?

610


Describe the two types of formbeans.

664


How the exceptions are handled in struts?

613


Why are springs better than struts?

704


What are the features of struts 2?

620


Define struts?

714


Difference between html tags and struts specific html tags

595


Do I have to credit struts on my own website?

639


Why do the struts tags provide for so little formatting?

672


How to combine the struts with velocity template?

582