某年的月初月末时间戳获取

package co.yixiang.modules.jhb.common;

import java.util.Calendar;
import java.util.Date;

/**
 * @author lwy
 * @since 2021年7月17日15:45:35
 */
public class SelectDateOfMonthUtil {

    /**
     * 获取某个月的月初时间和月末时间的时间戳 秒级，用于月份时间筛选
     * @param year 年份
     * @param month 月份
     * @param unitOfTime 时间单位（1为ms，1000为s，1000*60为分，以此类推）
     * @return times times[0] 月初时间   times[1]月末时间
     */
    public static long[] selectDateOfMonth(int year,int month,int unitOfTime){
        long[] times = new long[2];
        Calendar cal = Calendar.getInstance();
        cal.set(Calendar.YEAR, year);

        //当前月的第一天的00:00:00
        cal.set(Calendar.MONTH, month-1);
        cal.set(Calendar.DAY_OF_MONTH,cal.getMinimum(Calendar.DATE));
        System.out.println(cal.getTime());
        Date time1 = cal.getTime();
        time1.setHours(0);
        time1.setSeconds(0);
        time1.setMinutes(0);
        long timeInMillis1 = time1.getTime();
        times[0] = timeInMillis1/unitOfTime;

        //下个月的第一天的00:00:00
        cal.set(Calendar.MONTH, month);
        cal.set(Calendar.DAY_OF_MONTH,cal.getMinimum(Calendar.DATE));
        System.out.println(cal.getTime());
        Date time2 = cal.getTime();
        time2.setHours(0);
        time2.setSeconds(0);
        time2.setMinutes(0);
        long timeInMillis2 = time2.getTime();
        times[1] = timeInMillis2/1000;

        return times;
    }

}