what is BUSINESS DELIGATE PATTERN,DAO,VO,DTO?
- 6 Answers
- 26855 Views
- BOB Technologies, TCS, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / yathirajulu.mettupally
DTO pattern in j2ee is... Data Transerfer Object, which
exchange the data with enterprise beans.
VO : Value Objects is nothing but java beans which consists
getter & setter methods.
DAO: Data Access Object is consisting of business-loigic &
connecting to database.
Deligate Pattern:Which is a adapter(mediator)class decouples
presentation cliet & business-logic.
| Is This Answer Correct ? | 19 Yes | 3 No |
Answer / musarath
DAO is the Data acess Objects and VO is the value objects
which acts as a Model in MVC architecture...VO is nothing
but a bean consisting of getter and setter methods.DAO
consisits of business logic and code connecting the
database.
Not Sure of DTO and business delegate patterns.
| Is This Answer Correct ? | 16 Yes | 5 No |
Answer / 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 |
Answer / kris
every thing here
http://java.sun.com/blueprints/patterns/catalog.html
| Is This Answer Correct ? | 5 Yes | 3 No |
Answer / ravikiran(aptech mumbai)
Business Delegate:Is a design pattern used to hide the
remoteness of any component to the accessor
DAO:Is the data access object used to make the database
logic away fom the busines logic.By witing it in a seperate
method and calling in action
VO:Is the value object used in the development of enterprise
distributed applications to get and set the values
DTO:Is the data transfer object which will expose the
business methods to the jsps to call with out passing threw
the network barrier every time
| Is This Answer Correct ? | 8 Yes | 6 No |
Answer / kathiravan j
DAO is Data Access Object where we can access object using
dataf
| Is This Answer Correct ? | 5 Yes | 4 No |
how to debug struts project in netbean ?
What are the action classes in struts?
What is the use of jsonvalidation?
Explain the difference between dispatchaction and lookupdispatchaction in struts?
Briefly tell the two kinds of form beans.
What is struts actionmapping?
What is the purpose of @key?
How do you create message resource?
What is the default location of result pages and how can we change it?
In struts, how can we access java beans and their properties?
How to explain struts work flow
12 Answers CSS, iFlex, iGate, mpower, TCS,
Lists the bundled validators in struts?
Core Java 
