Java面向对象程序设计——设计日期类

设计日期类

【问题描述】借助Calendar类，设计一个日期类MyDate，能根据多种输入数据创建日期对象，可对日期进行计算，并以不同的模式输出日期。类图如下：

【输入形式】1-8的整数
【输出形式】输入1，则输出2010-10-10

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Scanner;
//-----以下为需填片段-------
class MyDate {
	Calendar c = Calendar.getInstance();
	String pattern = "yyyy-MM-dd";

	public MyDate() {
	}

	public MyDate(int y, int m, int d) {
		c.set(y, m - 1, d);
	}

	public MyDate(String source) {
		SimpleDateFormat sf = new SimpleDateFormat(pattern);
		Date d = new Date();
		try {
			d = sf.parse(source);
			c.setTime(d);
		} catch (ParseException e) {
			e.printStackTrace();
		}
	}

	public MyDate(String source, String pattern) {
		SimpleDateFormat sf = new SimpleDateFormat(pattern);
		setPattern(pattern);
		Date d = new Date();
		try {
			d = sf.parse(source);
			c.setTime(d);
		} catch (ParseException e) {
			e.printStackTrace();
		}
	}

	public MyDate after(int n) {
		c.add(Calendar.DATE, n);
		return new MyDate(c.get(Calendar.YEAR), c.get(Calendar.MONTH) + 1, c.get(Calendar.DATE));
	}

	public MyDate before(int n) {
		c.add(Calendar.DATE, -n);
		return new MyDate(c.get(Calendar.YEAR), c.get(Calendar.MONTH) + 1, c.get(Calendar.DATE));
	}

	public Date getDate() {
		return c.getTime();
	}

	public Calendar getCalendar() {
		return c;
	}

	public long getLong() {
		return c.getTimeInMillis();
	}

	public void setPattern(String pattern) {
		this.pattern = pattern;
	}

	public String toString() {
		SimpleDateFormat sf = new SimpleDateFormat(pattern);
		return sf.format(c.getTime());
	}
}
//--------------------------
public class Main {
	public static void main(String[] args) {
		int selected;
		Scanner in=new Scanner(System.in);
		selected=in.nextInt();
		MyDate md=new MyDate(2000,10,10);
		switch(selected){
		case 1:
			System.out.println(md);
			break;
		case 2:
			md=new MyDate("2010-10-10");
			System.out.println(md);
			break;
		case 3:
			md=new MyDate("2010/10/10","yyyy/MM/dd");
			System.out.println(md);
			break;
		case 4:
			System.out.println(md.after(8));
			break;
		case 5:
			System.out.println(md.before(20));
			break;
		case 6:
			System.out.println(md.getCalendar().get(Calendar.YEAR));
			break;
		case 7:
			md.setPattern("yyyy/MM/dd");
			System.out.println(md);
		}
		in.close();
	}
}

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