前段时间用JDK自带的Calendar类来处理日期，需要获取年、季，月，星期的起始日期，被折腾得要死要活。看了这篇文章 后，决定使用JodaTime重新写一下这个功能。
关于JodaTime可以看这篇文章：
废话不多说，直接贴代码。
1 import java.util.Date; 2 3 import org.joda.time.DateTime; 4 5 public class JodaDemo { 6 public static final int PERIOD_TYPE_YEAR = 0; 7 8 public static final int PERIOD_TYPE_MONTH = 1; 9 10 public static final int PERIOD_TYPE_HALFMONTH = 2;11 12 public static final int PERIOD_TYPE_WEEK = 3;13 14 public static final int PERIOD_TYPE_BIWEEK = 4;15 16 public static final int PERIOD_TYPE_QUARTER = 5;17 18 /**19 * 根据type获取日期期间 type为月的话 则返回月初与月末两个Date20 * 21 * @param currentDate22 * @param type23 * @return24 */25 public static Date[] getPeriodByType(Date currentDate, int type) {26 27 DateTime date = new DateTime(currentDate);28 Date fromDate = currentDate;29 Date toDate = currentDate;30 31 switch (type) {32 case PERIOD_TYPE_YEAR:33 fromDate = date.dayOfYear().withMinimumValue().toDate();34 toDate = date.dayOfYear().withMaximumValue().toDate();35 break;36 37 case PERIOD_TYPE_QUARTER:38 int month = date.getMonthOfYear();39 month = (month - 1) % 3;40 date = date.plusMonths(-month);41 fromDate = date.dayOfMonth().withMinimumValue().toDate();42 date = date.plusMonths(2);43 toDate = date.dayOfMonth().withMaximumValue().toDate();44 break;45 46 case PERIOD_TYPE_MONTH:47 fromDate = date.dayOfMonth().withMinimumValue().toDate();48 toDate = date.dayOfMonth().withMaximumValue().toDate();49 break;50 51 case PERIOD_TYPE_WEEK:52 fromDate = date.dayOfWeek().withMinimumValue().toDate();53 toDate = date.dayOfWeek().withMaximumValue().toDate();54 55 break;56 57 case PERIOD_TYPE_BIWEEK:58 fromDate = date.dayOfYear().withMinimumValue().toDate();59 toDate = date.dayOfYear().withMaximumValue().toDate();60 break;61 62 case PERIOD_TYPE_HALFMONTH:63 64 fromDate = date.dayOfYear().withMinimumValue().toDate();65 toDate = date.dayOfYear().withMaximumValue().toDate();66 67 break;68 69 default:70 break;71 }72 73 Date[] period = new Date[2];74 period[0] = fromDate;75 period[1] = toDate;76 return period;77 }78 } 然后写测试：
1 import static org.junit.Assert.*; 2 3 import java.util.Date; 4 5 import org.joda.time.DateTime; 6 import org.junit.Test; 7 8 9 public class JodaDemoTest {10 public static String dateFormat = "yyyy-MM-dd";11 @Test12 public void testGetPeriodByType() {13 DateTime dateTime = new DateTime("2013-12-26");14 Date[] weeks = JodaDemo.getPeriodByType(dateTime.toDate(), JodaDemo.PERIOD_TYPE_WEEK);15 assertEquals("2013-12-23", new DateTime(weeks[0]).toString(dateFormat));16 assertEquals("2013-12-29", new DateTime(weeks[1]).toString(dateFormat));17 18 // Date[] biWeek = JodaDemo.getPeriodByType(dateTime.toDate(), JodaDemo.PERIOD_TYPE_BIWEEK);19 // assertEquals("2013-12-01", new DateTime(biWeek[0]).toString(dateFormat));20 // assertEquals("2013-12-31", new DateTime(biWeek[1]).toString(dateFormat));21 22 Date[] months = JodaDemo.getPeriodByType(dateTime.toDate(), JodaDemo.PERIOD_TYPE_MONTH);23 assertEquals("2013-12-01", new DateTime(months[0]).toString(dateFormat));24 assertEquals("2013-12-31", new DateTime(months[1]).toString(dateFormat));25 26 Date[] quarters = JodaDemo.getPeriodByType(dateTime.toDate(), JodaDemo.PERIOD_TYPE_QUARTER);27 assertEquals("2013-10-01", new DateTime(quarters[0]).toString(dateFormat));28 assertEquals("2013-12-31", new DateTime(quarters[1]).toString(dateFormat));29 30 Date[] years = JodaDemo.getPeriodByType(dateTime.toDate(), JodaDemo.PERIOD_TYPE_YEAR);31 assertEquals("2013-01-01", new DateTime(years[0]).toString(dateFormat));32 assertEquals("2013-12-31", new DateTime(years[1]).toString(dateFormat));33 }34 35 } 测试通过：
注：按两周BIWEEK分割和按半个月HALFMONTH分割的功能还没完善。
使用Joda果然简单了很多，接下来有空可以看看源码，再深入理解一下。