Use the calendar class to get the year, month and day

import java.util.Calendar;

public class time_Calender {
    public static void main(String[] args) {
        Calendar cal=Calendar.getInstance();
        int day=cal.get(Calendar.DATE);
        int month=cal.get(Calendar.MONTH)+1;
        int year=cal.get(Calendar.YEAR);
        int dow=cal.get(Calendar.DAY_OF_WEEK);
        int dom=cal.get(Calendar.DAY_OF_MONTH);
        int doy=cal.get(Calendar.DAY_OF_YEAR);

        System.out.println("当前时间："+cal.getTime());
        System.out.println("日期："+day);
        System.out.println("月份："+month);
        System.out.println("年："+year);
        System.out.println("一周的第几天："+dow); //星期日为一周的第一天输出为 1，星期一输出为 2，以此类推
        System.out.println("一月的第几天："+dom);
        System.out.println("一年的第几天："+doy);

    }
}

The output result is:

Current time: fri May 29 15:19:24 CST 2020 date: 29 month: 5 years: the day of 2020 week: the day of June: the day of 29 year: 150