常用日期计算获某天的第一秒和最后一秒

下载地址

常用字符串处理

使用

String start = DateToStringBeginOrEnd(new Date(),true); //2020-11-05 00:00:00
String end = DateToStringBeginOrEnd(new Date(),false); //2020-11-05 23:59:59

源码

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

public class DateUtil {

    public void testTime() throws Exception {
        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Calendar c = Calendar.getInstance();
        //c.add(Calendar.MONTH, -1);    //得到前一个月
        c.add(Calendar.DATE, -1);    //得到前一天
        String jssj = DateToStringBeginOrEnd(c.getTime(),false);

    }
    /**
     * 获取某一天的0点0分0秒 或者 23点59分59秒
     * @param date
     * @param flag
     * @return
     */
    public String DateToStringBeginOrEnd(Date date, Boolean flag) {
        String time = null;
        SimpleDateFormat dateformat1 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Calendar calendar1 = Calendar.getInstance();
        //获取某一天的0点0分0秒 或者 23点59分59秒
        if (flag == true) {
            calendar1.setTime(date);
            calendar1.set(calendar1.get(Calendar.YEAR), calendar1.get(Calendar.MONTH), calendar1.get(Calendar.DAY_OF_MONTH),
                    0, 0, 0);
            Date beginOfDate = calendar1.getTime();
            time = dateformat1.format(beginOfDate);
            System.out.println(time);
        }else{
            Calendar calendar2 = Calendar.getInstance();
            calendar2.setTime(date);
            calendar1.set(calendar2.get(Calendar.YEAR), calendar2.get(Calendar.MONTH), calendar2.get(Calendar.DAY_OF_MONTH),
                    23, 59, 59);
            Date endOfDate = calendar1.getTime();
            time = dateformat1.format(endOfDate);
            System.out.println(time);
        }
        return time;
    }
}