在Java中获取上周的第一天和最后一天的时间

以下是使用Java获取上周第一天00:00:00和最后一天23:59:59的几种方法：

方法1：使用Java 8的java.time API（推荐）

import java.time.*;
import java.time.temporal.TemporalAdjusters;

public class LastWeekDates {
    public static void main(String[] args) {
        // 获取当前日期
        LocalDate today = LocalDate.now();
        
        // 获取上周的第一天(周一)和最后一天(周日)
        LocalDate lastWeekMonday = today.minusWeeks(1).with(TemporalAdjusters.previousOrSame(DayOfWeek.MONDAY));
        LocalDate lastWeekSunday = lastWeekMonday.plusDays(6);
        
        // 转换为当天的开始和结束时间
        LocalDateTime startOfLastWeek = lastWeekMonday.atStartOfDay(); // 00:00:00
        LocalDateTime endOfLastWeek = lastWeekSunday.atTime(LocalTime.MAX); // 23:59:59.999999999
        
        // 如果需要转换为Date对象
        ZonedDateTime startZoned = startOfLastWeek.atZone(ZoneId.systemDefault());
        ZonedDateTime endZoned = endOfLastWeek.atZone(ZoneId.systemDefault());
        Date startDate = Date.from(startZoned.toInstant());
        Date endDate = Date.from(endZoned.toInstant());
        
        System.out.println("上周第一天(周一) 00:00:00: " + startOfLastWeek);
        System.out.println("上周最后一天(周日) 23:59:59: " + endOfLastWeek);
    }
}

方法2：使用Calendar类（旧版API）

import java.util.*;
import java.text.SimpleDateFormat;

public class LastWeekDatesLegacy {
    public static void main(String[] args) {
        Calendar calendar = Calendar.getInstance();
        
        // 设置到上周
        calendar.add(Calendar.WEEK_OF_YEAR, -1);
        
        // 获取上周的第一天(周一)
        calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        calendar.set(Calendar.MILLISECOND, 0);
        Date startOfLastWeek = calendar.getTime();
        
        // 获取上周的最后一天(周日)
        calendar.add(Calendar.DAY_OF_WEEK, 6);
        calendar.set(Calendar.HOUR_OF_DAY, 23);
        calendar.set(Calendar.MINUTE, 59);
        calendar.set(Calendar.SECOND, 59);
        calendar.set(Calendar.MILLISECOND, 999);
        Date endOfLastWeek = calendar.getTime();
        
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
        System.out.println("上周第一天(周一) 00:00:00: " + sdf.format(startOfLastWeek));
        System.out.println("上周最后一天(周日) 23:59:59: " + sdf.format(endOfLastWeek));
    }
}