java date的一些操作

// DateUtil
// beginOfDay   endOfDay 获取当天的最早时间与最晚时间
// offsetDay 向前或向后推移几天，向前为负数，向后为正数
// cn.hutool.core.date.DateUtil

private Long startTime;
private Long endTime;
startTime = DateUtil.beginOfDay(DateUtil.offsetDay(new Date(), 0)).getTime() / 1000;
endTime = DateUtil.endOfDay(DateUtil.offsetDay(new Date(), 0)).getTime() / 1000;

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// 获取当天，当周
  public static final String DATE_FORMAT_DAY_TIME = "yyyy-MM-dd HH:mm:ss";
    public static final String DATE_TYPE_WEEK = "week";
    public static final String DATE_TYPE_MONTH = "month";
    public static final String DATE_TYPE_YEAR = "year";
    public static final String DATE_TYPE_DAY = "day";


    public static  Map<String,String>  getTimeRange(String dateFormat,String dateType,Date date){
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(date);
        calendar.setTimeZone(TimeZone.getTimeZone("GMT+8"));
        if("week".equals(dateType)){
            if (calendar.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
                calendar.add(Calendar.DAY_OF_YEAR,-1);
            }
            calendar.add(Calendar.DAY_OF_WEEK, -(calendar.get(Calendar.DAY_OF_WEEK) - 2));
        } else if ("month".equals(dateType)) {
            calendar.add(Calendar.MONTH, 0);
            calendar.set(Calendar.DAY_OF_MONTH, 1);
        } else if ("year".equals(dateType)) {
            calendar.add(Calendar.YEAR, 0);   // -1表示去年，0表示今年，1表示明年月，上下年份以此类型
            calendar.set(Calendar.DAY_OF_YEAR, calendar.getActualMinimum(Calendar.DAY_OF_YEAR));
        }
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        long startTime = calendar.getTimeInMillis();
        //end of the week
        if("week".equals(dateType)){
            calendar.add(Calendar.DAY_OF_WEEK, 6);
        }else if ("month".equals(dateType)) {
            calendar.add(Calendar.MONTH, 1);
            calendar.set(Calendar.DAY_OF_MONTH, 0);
        }else if ("year".equals(dateType)) {
            calendar.add(Calendar.YEAR, 0);   // -1表示去年，0表示今年，1表示明年月，上下年份以此类型
            calendar.set(Calendar.DAY_OF_YEAR, calendar.getActualMaximum(Calendar.DAY_OF_YEAR));
        }
        calendar.set(Calendar.HOUR_OF_DAY, 23);
        calendar.set(Calendar.MINUTE, 59);
        calendar.set(Calendar.SECOND, 59);
        calendar.set(Calendar.MILLISECOND, 999);
        long endTime = calendar.getTimeInMillis();
        SimpleDateFormat format = new SimpleDateFormat(dateFormat);
        System.out.println(format.format(startTime));
        System.out.println(format.format(endTime));
        Map<String,String> map = new HashMap<>();
        map.put("startTime",format.format(startTime));
        map.put("endTime",format.format(endTime));
        return map;
    }