算法－第四版－练习1.2.11解答

根据Date的API实现一个SmartDate类型，在日期非法时抛出一个异常。

/**
 * Description : 
 * Author      : mn@furzoom.com
 * Date        : Sep 26, 2016 5:40:07 PM
 * Copyright (c) 2013-2016, http://furzoom.com All Rights Reserved.
 */
package com.furzoom.lab.algs.ch102;

/**
 * ClassName    : E10211 <br>
 * Function     : TODO ADD FUNCTION. <br>
 * date         : Sep 26, 2016 5:40:07 PM <br>
 * 
 * @version 
 */
public class E10211
{
    public static void main(String[] args)
    {
        try {
            SmartDate date = new SmartDate(13, 1, 1999);
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        }
        
        try {
            SmartDate date = new SmartDate(2, 29, 2000);
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        }
         
        try {
            SmartDate date = new SmartDate(2, 29, 1900);
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        }
         
        try {
            SmartDate date = new SmartDate(2, 28, 2002);
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        }
         
        try {
            SmartDate date = new SmartDate(4, 31, 2000);
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        }
        
        try {
            SmartDate date = new SmartDate(5, 31, 2000);
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        }
        
    }
}

class SmartDate
{
    private final int month;
    private final int day;
    private final int year;
    
    public SmartDate(int m, int d, int y)
    {
        if (!validate(m, d, y))
            throw new IllegalArgumentException("Argument illegal " + m + "/" + d + "/" + y);
        this.month = m;
        this.day = d;
        this.year = y;
    }
    
    public int month()
    {
        return month;
    }
    
    public int day()
    {
        return day;
    }
    
    public int year()
    {
        return year;
    }
    
    public String toString()
    {
        return month + "/" + day + "/" + year;
    }
    
    private boolean validate(int m, int d, int y)
    {
        if (y == 0 || y < -1000 || y > 10000)
            return false;
        if (m < 1 || m > 12)
            return false;
        if (d < 1 || d > 31)
            return false;
        int[] months = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
        if (d > months[m])
            return false;
        if (!(y % 400 == 0 || (y % 4 == 0 && y % 100 != 0)))
        {
            if (d > 28)
                return false;
        }
        return true;
    }
}

结果：

java.lang.IllegalArgumentException: Argument illegal 13/1/1999
	at com.furzoom.lab.algs.ch102.SmartDate.<init>(E10211.java:68)
	at com.furzoom.lab.algs.ch102.E10211.main(E10211.java:21)
java.lang.IllegalArgumentException: Argument illegal 2/29/1900
	at com.furzoom.lab.algs.ch102.SmartDate.<init>(E10211.java:68)
	at com.furzoom.lab.algs.ch102.E10211.main(E10211.java:33)
java.lang.IllegalArgumentException: Argument illegal 4/31/2000
	at com.furzoom.lab.algs.ch102.SmartDate.<init>(E10211.java:68)
	at com.furzoom.lab.algs.ch102.E10211.main(E10211.java:45)

算法－第四版－1.2 数据抽象－习题索引汇总

算法－第四版习题索引汇总