实现方式分别采用jdk7的Calendar和jdk8的LocalDate
Calendar实现
import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;/*** 根据给定时间获取周、月度、季度、年度开始结束时间* @author wsp*/public class DateCalendarUtil {/*** @Description: 获取月份第一天* @Author: wsp**/public static Calendar getMonthStart(Date date) { // 月份开始Calendar startCalendar = Calendar.getInstance();startCalendar.setTime(date);//set方法将给定日历字段设置为给定值//下面代码作用是将日历设置为给定日期月份天数的第一天startCalendar.set(Calendar.DAY_OF_MONTH, 1);return startCalendar;}/*** @Description: 获取月份最后一天* @Author: wsp**/public static Calendar getMonthEnd(Date date) { // 月份结束Calendar endCalendar = Calendar.getInstance();endCalendar.setTime(date);//getActualMaximum方法用来返回给定日历字段属性的最大值//endCalendar.getActualMaximum(Calendar.DAY_OF_MONTH) 代码作用为返回日历该月份的最大值//set方法，将该日历的给定月份设置为最大天数endCalendar.set(Calendar.DAY_OF_MONTH, endCalendar.getActualMaximum(Calendar.DAY_OF_MONTH));return endCalendar;}/*** @Description: 获取季度第一天* 1.根据给定日期计算当前季度的第一个月份* 2.设置日历的月份为当前季度的第一个月份* 3.最后设置日历月份天数为第一天即可* @Author: wsp**/public static Calendar getQuarterStart(Date date) {Calendar startCalendar = Calendar.getInstance();startCalendar.setTime(date);//get方法：获取给定日历属性的值，如 endCalendar.get(Calendar.MONTH) 获取日历的月份//计算季度数：由于月份从0开始，即1月份的Calendar.MONTH值为0,所以计算季度的第一个月份只需 月份 / 3 * 3startCalendar.set(Calendar.MONTH, (((int) startCalendar.get(Calendar.MONTH)) / 3) * 3);startCalendar.set(Calendar.DAY_OF_MONTH, 1);return startCalendar;}/*** @Description: 获取季度最后一天* @Author: wsp**/public static Calendar getQuarterEnd(Date date) { // 季度结束Calendar endCalendar = Calendar.getInstance();endCalendar.setTime(date);//计算季度数：由于月份从0开始，即1月份的Calendar.MONTH值为0,所以计算季度的第三个月份只需 月份 / 3 * 3 + 2endCalendar.set(Calendar.MONTH, (((int) endCalendar.get(Calendar.MONTH)) / 3) * 3 + 2);endCalendar.set(Calendar.DAY_OF_MONTH, endCalendar.getActualMaximum(Calendar.DAY_OF_MONTH));return endCalendar;}/*** @Description: 获取年份第一天* @Author: wsp**/public static Calendar getYearStart(Date date) { // 年份开始Calendar startCalendar = Calendar.getInstance();startCalendar.setTime(date);startCalendar.set(Calendar.DAY_OF_YEAR, 1);return startCalendar;}/*** @Description: 获取年份最后一天* @Author: wsp**/public static Calendar getYearEnd(Date date) { // 年份结束Calendar endCalendar = Calendar.getInstance();endCalendar.setTime(date);endCalendar.set(Calendar.DAY_OF_YEAR, endCalendar.getActualMaximum(Calendar.DAY_OF_YEAR));return endCalendar;}/*** @Description: 获取当前周第一天（周一）* @Author: wsp**/public static Date getWeekStart(Date date) {Calendar calendar = Calendar.getInstance();calendar.setTime(date);//获取传入日期属于星期几，根据星期几进行不同处理int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK);//周日：需要减去6天为周一。（当传入日期为周日时，若我们直接设置日历天数为周一，则日期会变为下一周的周一，而非当前周）if (dayOfWeek == 1) {calendar.add(Calendar.DAY_OF_MONTH, -6);} else {//周二 至 周六：直接获取周一即可calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);}return calendar.getTime();}/*** @Description: 获取当前周最后一天（周日）* @Author: wsp**/public static Date getWeekEnd(Date date) {Calendar calendar = Calendar.getInstance();calendar.setTime(getWeekStart(date));calendar.add(Calendar.DAY_OF_MONTH, 6);return calendar.getTime();}public static void main(String[] args) throws ParseException {String dateStr = "-10-17";SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");Date date = sdf.parse(dateStr);String startMonthDay = sdf.format(getMonthStart(date).getTime());String endMonthDay = sdf.format(getMonthEnd(date).getTime());System.out.printf("月份的第一天：%s, 月份的最后一天：%s%n", startMonthDay, endMonthDay);String startQuarterDay = sdf.format(getQuarterStart(date).getTime());String endQuarterDay = sdf.format(getQuarterEnd(date).getTime());System.out.printf("季度第一天：%s, 季度最后一天：%s%n", startQuarterDay, endQuarterDay);String startYearDay = sdf.format(getYearStart(date).getTime());String endYearDay = sdf.format(getYearEnd(date).getTime());System.out.printf("年份第一天：%s, 年份最后一天：%s%n", startYearDay, endYearDay);String startWeekDay = sdf.format(getWeekStart(date));String endWeekDay = sdf.format(getWeekEnd(date));System.out.printf("当前周周一：%s, 当前周周日：%s%n", startWeekDay, endWeekDay);}}
输出：
月份的第一天：-10-01, 月份的最后一天：-10-31季度第一天：-10-01, 季度最后一天：-12-31年份第一天：-01-01, 年份最后一天：-12-31当前周周一：-10-11, 当前周周日：-10-17
LocalDate实现
import java.time.LocalDate;import java.time.format.DateTimeFormatter;import java.time.temporal.ChronoField;public class DateUtil {/*** @Description: 获取季度第一天* @Author: wsp**/public static LocalDate getQuarterStart(LocalDate localDate) {//设置日期天数为第一天localDate = localDate.withDayOfMonth(1);long month = localDate.getMonth().getValue();if (1 <= month && month <= 3) {localDate = localDate.withMonth(1);} else if (4 <= month && month <= 6) {localDate = localDate.withMonth(4);} else if (7 <= month && month <= 9) {localDate = localDate.withMonth(7);} else {localDate = localDate.withMonth(10);}return localDate;}/*** @Description: 获取季度最后一天* @Author: wsp**/private static LocalDate getQuarterEnd(LocalDate localDate) {//设置日期天数为最后一天localDate = localDate.withDayOfMonth(localDate.lengthOfMonth());long month = localDate.getMonth().getValue();if (1 <= month && month <= 3) {localDate = localDate.withMonth(3);} else if (4 <= month && month <= 6) {localDate = localDate.withMonth(6);} else if (7 <= month && month <= 9) {localDate = localDate.withMonth(9);} else {localDate = localDate.withMonth(12);}return localDate;}public static void main(String[] args) {DateTimeFormatter format = DateTimeFormatter.ofPattern("yyyy-MM-dd");LocalDate localDate = LocalDate.of(, 10, 17);//周LocalDate startWeekDay = localDate.with(ChronoField.DAY_OF_WEEK, 1);LocalDate endWeekDay = localDate.with(ChronoField.DAY_OF_WEEK, 7);System.out.printf("当前周周一：%s, 当前周周日：%s%n", format.format(startWeekDay), format.format(endWeekDay));//月份LocalDate startMonthDay = localDate.with(ChronoField.DAY_OF_MONTH, 1);//LocalDate endMonthDay = localDate.with(ChronoField.DAY_OF_MONTH, localDate.lengthOfMonth());LocalDate endMonthDay = localDate.withDayOfMonth(localDate.lengthOfMonth());System.out.printf("月份的第一天：%s, 月份的最后一天：%s%n", format.format(startMonthDay), format.format(endMonthDay));//季度LocalDate startQuarterDay = getQuarterStart(localDate);LocalDate endQuarterDay = getQuarterEnd(localDate);System.out.printf("季度第一天：%s, 季度最后一天：%s%n", format.format(startQuarterDay), format.format(endQuarterDay));//年份LocalDate startYearDay = localDate.with(ChronoField.DAY_OF_YEAR, 1);LocalDate endYearDay = localDate.with(ChronoField.DAY_OF_YEAR, localDate.lengthOfYear());System.out.printf("年份第一天：%s, 年份最后一天：%s%n", format.format(startYearDay), format.format(endYearDay));}}
输出：
当前周周一：-10-11, 当前周周日：-10-17月份的第一天：-10-01, 月份的最后一天：-10-31季度第一天：-10-01, 季度最后一天：-12-31年份第一天：-01-01, 年份最后一天：-12-31
总结：
可以看到使用jdk8的LocalDate类简单很多，也更容易理解。
