Java代码案例26——开关分支计算某年某月某日是这一年的第几天

package xiangmu;
public class Ceshi {
    public static void main(String args[]) {
        int nian = 2020;
        int yue = 3;
        int ri = 5;
        int tian = 0;
        switch(yue) {
            case 12: tian = tian + 30;
            case 11: tian = tian + 31;
            case 10: tian = tian + 30;
            case 9: tian = tian + 31;
            case 8: tian = tian + 31;
            case 7: tian = tian + 30;
            case 6: tian = tian + 31;
            case 5: tian = tian + 30;
            case 4: tian = tian + 31;
            case 3:
                if(nian % 4 == 0 && nian % 100 != 0 || nian % 400 == 0) {
                    tian = tian + 29;
                }else {
                    tian = tian + 28;
                }
            case 2: tian = tian + 31;
            case 1: tian = tian + ri;
        }
        dayin(nian+"年"+yue+"月"+ri+"日是这一年的第"+tian+"天");
    }
    public static void dayin(String zifuchuan) {
        System.out.println(zifuchuan);
    }
}
2020年3月5日是这一年的第65天