die.java

来自「《Java与模式》一书的源代码」· Java 代码 · 共 42 行

package com.javapatterns.multilingual.dice;

import java.util.Date;
import java.util.Random;

public class Die
{
    private static Die die1 = new Die();
    private static Die die2 = new Die();

    private Die()
    {
    }

    public static Die getInstance(int whichOne)
    {
        if (whichOne == 1)
        {
            return die1;
        }
        else
        {
            return die2;
        }
    }

    public synchronized int dice()
    {
        Date d = new Date();

        Random r = new Random(d.getTime());
        int value = r.nextInt();
        value = Math.abs(value);

        value %= 6;
        value += 1;
        System.out.println(value);
        return value;
    }

}