how to exclude a property from object while putting into hashmap in java

Question

Lets say, Employee class has three properties.

class Employee {
    int id;
    String name;
    String team;

    public Employee(){
        this.id = id;
        this.name = name;
        this.team = team;
    }
}

I want to remove team from the object before putting into HashMap .

Map<Integer, Employee> empMap = new HashMap<>();

Employee e1 = new Employee(100, "John", "Dev");
Employee e2 = new Employee(101, "Mary", "Dev");
Employee e3 = new Employee(103, "Andy", "QA");

empMap.put(e1.getId(), e1);
empMap.put(e2.getId(), e2);
empMap.put(e1.getId(), e3);

The values in empMap shouldn't have team property in it. Creating new objects would work but it is costly in real time. Is there a way to achieve this without creating new objects.

Answer 1

One option, as you have mentioned, is to create new objects without the team property. Another is to use a façade

public class MapEmpFacade extends Employee {
  public MapEmpFacade(Employee emp) {
    //define all methods to return the method results from emp, except for getTeam
  }
  public int getTeam() { return null; } //override getTeam
}

Answer 2

You may review your design to be sure you need the property to be there. You are holding Employee references in the map , the team property is there and probably is correctly representing an Employee ... you can just avoid using the team property ... or maybe you want to have a Person class.

If you are using those instances from some framework to do something (eg: serialization, persistence, etc) it should probably provide a way to ignore/skip a property in your object.