IMoney.java

package junit.samples.money;

/**
 * The common interface for simple Monies and MoneyBags
 *
 */
interface IMoney {
	/**
	 * Adds a money to this money.
	 */
	public abstract IMoney add(IMoney m);
	/**
	 * Adds a simple Money to this money. This is a helper method for
	 * implementing double dispatch
	 */
	IMoney addMoney(Money m);
	/**
	 * Adds a MoneyBag to this money. This is a helper method for
	 * implementing double dispatch
	 */
	IMoney addMoneyBag(MoneyBag s);
	/**
	 * Tests whether this money is zero
	 */
	public abstract boolean isZero();
	/**
	 * Multiplies a money by the given factor.
	 */
	public abstract IMoney multiply(int factor);
	/**
	 * Negates this money.
	 */
	public abstract IMoney negate();
	/**
	 * Subtracts a money from this money.
	 */
	public abstract IMoney subtract(IMoney m);
}