java输入一个日期返回星期几

Question

不要网上搜来的答案。。我还是不知道该用什么方法呀
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public class Weekday {
public int year;
public int month;
public int day;
public Weekday(int year,int month,int day){
this.year = year;
this.month = month;
this.day = day;
}
public Weekday(){}
public void showWeekday()throws Throwable {
Calendar temp = null;
temp.set(this.year, this.month, this.day);
int x = temp.get(Calendar.DAY_OF_WEEK)-1;
switch(x){
case 0:
System.out.println("星期日");
break;
case 1:
System.out.println("星期一");
break;
case 2:
System.out.println("星期二");
break;
case 3:
System.out.println("星期三");
break;
case 4:
System.out.println("星期四");
break;
case 5:
System.out.println("星期五");
break;
case 6:
System.out.println("星期六");
break;
default:
System.out.println("出错啦");
}

}
}
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public class TestWeekday {
public static void main(String args[]) throws Throwable{
Scanner sc = new Scanner(System.in);
Weekday wkd = new Weekday();
wkd.year = sc.nextInt();
wkd.month = sc.nextInt();
wkd.day = sc.nextInt();
wkd.showWeekday();
}
}
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求大神教导

Answer 1

    public void showWeekday() throws Throwable {
        Calendar temp = Calendar.getInstance();// 需要初始化
        temp.set(this.year, this.month - 1, this.day);// 月份从0开始
        int x = temp.get(Calendar.DAY_OF_WEEK);
        switch (x) {
        case Calendar.SUNDAY:
            System.out.println("星期日");
            break;
        case Calendar.MONDAY:
            System.out.println("星期一");
            break;
        case Calendar.TUESDAY:
            System.out.println("星期二");
            break;
        case Calendar.WEDNESDAY:
            System.out.println("星期三");
            break;
        case Calendar.THURSDAY:
            System.out.println("星期四");
            break;
        case Calendar.FRIDAY:
            System.out.println("星期五");
            break;
        case Calendar.SATURDAY:
            System.out.println("星期六");
            break;
        default:
            System.out.println("出错啦");
        }
    }

Answer 2

import java.util.Calendar;

public class Test {
/**
* @param args
*/
public static void main(String[] args) {
// 测试用的年月
int year = 2014;
int month = 5;
int day = 17;

// 取得月末的日期,即这个月有多少天
Calendar temp = Calendar.getInstance();
temp.set(year, month-1,day);
int x = temp.get(Calendar.DAY_OF_WEEK);
System.out.println(getWeek(x));
}

// 转换成星期几
private static String getWeek(int key) {
switch (key) {
case 1:
return "星期日";
case 2:
return "星期一";
case 3:
return "星期二";
case 4:
return "星期三";
case 5:
return "星期四";
case 6:
return "星期五";
case 7:
return "星期六";
}
return "";
}
}本回答被提问者采纳