package com.olm.util;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**
 * ClassName:LasMonth Package:com.olm.util Date:2020/8/6 Auth:penghui@olm.com.cn
 */
public class LasMonth {
    public static void main(String... args) {
        //SimpleDateFormat format233 = new SimpleDateFormat("yyyy-MM-dd");
        //Calendar d = Calendar.getInstance();
        //Date dd = new LastMonthDate().convert(d);
        //Date lld = new LastLastMonthDate().convert(d);
        //System.out.println(format233.format(dd));
        //System.out.println(format233.format(lld));
        //System.out.println(new LasMonth().getFisrtDayOfMonth());
    }

    public String getFisrtDayOfMonth() {
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cale =  Calendar.getInstance();
        cale.add(Calendar.MONTH, 0);
        cale.set(Calendar.DAY_OF_MONTH, 1);
        return format.format(cale.getTime());
    }

    interface Convertor<S, R> {
        R convert(S s);
    }

    static public class LastMonthDate implements Convertor<Calendar, Date> {
        public Date convert(Calendar calendar) {
            calendar.add(Calendar.MONTH, -1);
            calendar.set(Calendar.DAY_OF_MONTH, 25);
            return calendar.getTime();
        }
    }

    static public class LastLastMonthDate implements Convertor<Calendar, Date> {
        public Date convert(Calendar calendar) {
            calendar.add(Calendar.MONTH, -1);
            calendar.set(Calendar.DAY_OF_MONTH, 26);
            return calendar.getTime();
        }
    }
}