java中判断给定一个日期string格式，判断今天是否在指定日期时间的这一周内，并返回两个日期之间相隔的周数

可以将日期字符串转换为`LocalDate`对象，然后再将其转换为`LocalDateTime`对象，接着按照上述方法进行判断，并计算两个日期之间相隔的周数。

具体步骤如下：

1. 将给定的日期字符串转换为`LocalDate`对象。

String dateString = "2021-11-08";
LocalDate date = LocalDate.parse(dateString);

2. 将`LocalDate`对象转换为`LocalDateTime`对象。

LocalDateTime dateTime = date.atStartOfDay();

3. 获取当前日期时间的`LocalDateTime`对象。

LocalDateTime now = LocalDateTime.now();

4. 计算给定日期时间所在周的开始时间和结束时间。

LocalDateTime startOfWeek = dateTime.with(TemporalAdjusters.previousOrSame(DayOfWeek.MONDAY)).with(LocalTime.MIN);
LocalDateTime endOfWeek = startOfWeek.plusDays(6).with(LocalTime.MAX);

5. 判断当前日期时间是否在指定日期时间的这一周内。

boolean isInWeek = now.isAfter(startOfWeek) && now.isBefore(endOfWeek);

6. 计算两个日期之间相隔的周数。

long weeksBetween = ChronoUnit.WEEKS.between(dateTime, now);

完整代码如下：

import java.time.DayOfWeek;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjusters;

public class DateTimeExample {
    public static void main(String[] args) {
        String dateString = "2021-11-08";
        LocalDate date = LocalDate.parse(dateString);
        LocalDateTime dateTime = date.atStartOfDay();
        LocalDateTime now = LocalDateTime.now();

        LocalDateTime startOfWeek = dateTime.with(TemporalAdjusters.previousOrSame(DayOfWeek.MONDAY)).with(LocalTime.MIN);
        LocalDateTime endOfWeek = startOfWeek.plusDays(6).with(LocalTime.MAX);

        boolean isInWeek = now.isAfter(startOfWeek) && now.isBefore(endOfWeek);
        long weeksBetween = ChronoUnit.WEEKS.between(dateTime, now);

        System.out.println(isInWeek);
        System.out.println(weeksBetween);
    }
}