Building Data Objects

• Once you have the interfaces, the data objects should be easy to discern.
• Data objects don't have many functional methods, mostly just descriptive (getX) methods.

import java.io.*;


public class Money extends ValueObject {
  protected int _cents;

  public Money(Integer cents) {
    this (cents.intValue());
  }

  public Money(int cents) {
    super (cents + " cents.");
    _cents = cents;
  }

  public int getCents() {
    return _cents;
  }

  public void add(Money otherMoney) {
    _cents += otherMoney.getCents();
  }

  public void subtract(Money otherMoney) {
    _cents -= otherMoney.getCents();
  }

  public boolean greaterThan(Money otherMoney) {
    if (_cents > otherMoney.getCents()) {
      return true;
    }
    return false;
  }

  public boolean isNegative() {
    return _cents < 0;
  }

  public boolean equals(Object object) {
    if (object instanceof Money) {
      Money otherMoney = (Money) object;

      return (_cents == otherMoney.getCents());
    }
    return false;
  }
}