Encapsulation in Java

Question

Possible Duplicate:
Considering object encapsulation, should getters return an immutable property?

Does encapsulation mandate immutability of the class?

Class Employee{
  private Date hireDate;
  public Date getHireDate(){
   return hireDate;
  }
}

In Some client Method:

Employee emp = new Employee();
Date temp = emp.getHireDate();
temp.setTime(...);//The Hiredate of the employee would be corrupted...

Answer 1

No. It just means that access to the class's members is only permitted via its methods.

If you want to prevent the kind of problem you highlight, the class could return a copy of the Date object. But even then, you could provide a setHireDate() method and still rightly refer to the date as "encapsulated".