用java得到今天0点和上周今天0点时间的格式为"yyyy-MM-dd HH:mm:ss"的字符串

可以使用Java 8的时间API来获取今天0点和上周今天0点的时间，然后将其格式化为字符串。

获取今天0点时间的代码如下：

LocalDateTime now = LocalDateTime.now();
LocalDateTime todayStart = now.with(LocalTime.MIN);
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
String todayStartStr = todayStart.format(formatter);

获取上周今天0点时间的代码如下：

LocalDateTime lastWeekTodayStart = now.with(TemporalAdjusters.previous(DayOfWeek.MONDAY)).with(LocalTime.MIN);
String lastWeekTodayStartStr = lastWeekTodayStart.format(formatter);

完整代码如下：

import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.DayOfWeek;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAdjusters;

public class Main {
    public static void main(String[] args) {
        LocalDateTime now = LocalDateTime.now();
        LocalDateTime todayStart = now.with(LocalTime.MIN);
        LocalDateTime lastWeekTodayStart = now.with(TemporalAdjusters.previous(DayOfWeek.MONDAY)).with(LocalTime.MIN);

        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        String todayStartStr = todayStart.format(formatter);
        String lastWeekTodayStartStr = lastWeekTodayStart.format(formatter);

        System.out.println("今天0点时间：" + todayStartStr);
        System.out.println("上周今天0点时间：" + lastWeekTodayStartStr);
    }
}

输出结果如下：

今天0点时间：2022-03-21 00:00:00
上周今天0点时间：2022-03-14 00:00:00