WeekFields weekFields= WeekFields.ISO;
LocalDate now = LocalDate.now();
//输入你想要的年份和周数
LocalDate localDate = now.withYear(2021).with(weekFields.weekOfYear(),1);
//以周一为每周的第一天
//周一(第一天)
LocalDate localDate1 = localDate.with(weekFields.dayOfWeek(), 1L);
//周日(第七天)
LocalDate localDate7 = localDate.with(weekFields.dayOfWeek(), 7L);
//以周日为每周的第一天
//周日(第一天)
LocalDate localDate1 = localDate.with(WeekFields.of(Locale.US).dayOfWeek(), 1L);
//周六(第七天)
LocalDate localDate7 = localDate.with(weekFields.dayOfWeek(), 6L);