Java获取今天、本周、本月、本季度、上月、上一年的时间范围

在Java中，我们可以使用Java 8引入的新的日期和时间API来轻松获取当前日期、本周、本月、本季度、上月和去年的时间范围。这个API在java.time包中，它比旧的java.util.Date和java.util.Calendar类更加强大和灵活。以下是如何使用这个API来获取这些时间范围的示例：
首先，我们需要获取当前日期：

import java.time.LocalDate;
LocalDate today = LocalDate.now();

1. 本周：

   import java.time.DayOfWeek;
   import java.time.LocalDate;
   import java.time.temporal.TemporalAdjusters;
   LocalDate mondayThisWeek = LocalDate.now().with(TemporalAdjusters.previousOrSame(DayOfWeek.MONDAY));
   LocalDate sundayThisWeek = LocalDate.now().with(TemporalAdjusters.nextOrSame(DayOfWeek.SUNDAY));

2. 本月：

   import java.time.LocalDate;
   import java.time.temporal.TemporalAdjusters;
   LocalDate firstDayOfMonth = LocalDate.now().with(TemporalAdjusters.firstDayOfMonth());
   LocalDate lastDayOfMonth = LocalDate.now().with(TemporalAdjusters.lastDayOfMonth());

3. 本季度：

   import java.time.LocalDate;
   import java.time.temporal.TemporalAdjusters;
   import java.time.temporal.ChronoUnit;
   int quarter = (int) LocalDate.now().getMonth().getValue() / 3 + 1;  // 1-based index (Q1 = 1, Q2 = 2, Q3 = 3, Q4 = 4)
   LocalDate firstDayOfQuarter = LocalDate.now().with(TemporalAdjusters.firstDayOfQuarter());
   LocalDate lastDayOfQuarter = LocalDate.now().with(TemporalAdjusters.lastDayOfQuarter());

4. 上月：

   import java.time.LocalDate;
   import java.time.temporal.TemporalAdjusters;
   import java.time.temporal.ChronoUnit;
   LocalDate firstDayOfPreviousMonth = LocalDate.now().with(TemporalAdjusters.previous(ChronoUnit.MONTHS));
   LocalDate lastDayOfPreviousMonth = LocalDate.now().with(TemporalAdjusters.lastDayOfPreviousMonth());

5. 去年：

   import java.time.LocalDate;
   import java.time.temporal.ChronoUnit;
   LocalDate firstDayOfYear = LocalDate.now().with(TemporalAdjusters.firstDayOfYear());
   LocalDate lastDayOfYear = LocalDate.now().with(TemporalAdjusters.lastDayOfYear());