money.java

来自「含有uml的多个实例及实例的java源码。」· Java 代码 · 共 86 行

/*
 * ATM Example system - file Money.java
 *
 * copyright (c) 2001 - Russell C. Bjork
 *
 */
 
package banking;

/** Representation for money amounts */

public class Money
{
    /** Constructor
     *
     *  @param dollars whole dollar amount
     */
    public Money(int dollars)
    {
        this(dollars, 0);
    }
    
    /** Constructor
     *
     *  @param dollars dollar part of amount
     *  @param cents cents part of amount
     */
    public Money(int dollars, int cents)
    {
        this.cents = 100L * dollars + cents;
    }
    
    /** Copy constructor
     *
     *  @param toCopy the Money object to copy
     */
    public Money(Money toCopy)
    {
        this.cents = toCopy.cents;
    }
    
    /** Create a string representation of this amount
     *
     *  @return string representation of this amount
     */
    public String toString()
    {
        return "$" + cents/100 + 
            (cents %100 >= 10  ? "." + cents % 100 : ".0" + cents % 100);
    }
    
    /** Add an amount of money to this
     *
     *  @param amountToAdd the amount to add
     */
    public void add(Money amountToAdd)
    {
        this.cents += amountToAdd.cents;
    }
    
    /** Subtract an amount of money from this
     *
     *  @param amountToSubtract the amount to subtract
     *
     *  Precondition: amount must be <= this amount
     */
    public void subtract(Money amountToSubtract)
    {
        this.cents -= amountToSubtract.cents;
    }
    
    /** Compare this to another amount
     *
     *  @param compareTo the amount to compare to
     *  @return true if this amount is <= compareTo amount
     */
    public boolean lessEqual(Money compareTo)
    {
        return this.cents <= compareTo.cents;
    }
    
    /** Instance variable: this amount represented as a number of cents 
     */
    private long cents; 
}