修复DateUtil.betweenYear闰年2月问题

hutool-core/src/main/java/org/dromara/hutool/core/date/CalendarUtil.java

@@ -371,6 +371,7 @@ public class CalendarUtil {
 	// endregion
 
 	// region ----- isSame
+
 	/**
 	 * 比较两个日期是否为同一天
 	 *
@@ -647,6 +648,7 @@ public class CalendarUtil {
 	}
 
 	// region ----- parse
+
 	/**
 	 * 通过给定的日期格式解析日期时间字符串。<br>
 	 * 传入的日期格式会逐个尝试，直到解析成功，返回{@link Calendar}对象，否则抛出{@link DateException}异常。
@@ -796,4 +798,26 @@ public class CalendarUtil {
 
 		return age;
 	}
+
+	/**
+	 * 是否为本月第一天
+	 *
+	 * @param calendar {@link Calendar}
+	 * @return 是否为本月最后一天
+	 * @since 6.0.0
+	 */
+	public static boolean isFirstDayOfMonth(final Calendar calendar) {
+		return 1 == calendar.get(Calendar.DAY_OF_MONTH);
+	}
+
+	/**
+	 * 是否为本月最后一天
+	 *
+	 * @param calendar {@link Calendar}
+	 * @return 是否为本月最后一天
+	 * @since 5.8.27
+	 */
+	public static boolean isLastDayOfMonth(final Calendar calendar) {
+		return calendar.get(Calendar.DAY_OF_MONTH) == calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
+	}
 }

hutool-core/src/main/java/org/dromara/hutool/core/date/DateBetween.java

@@ -148,16 +148,21 @@ public class DateBetween implements Serializable {
 		final Calendar endCal = DateUtil.calendar(end);
 
 		final int result = endCal.get(Calendar.YEAR) - beginCal.get(Calendar.YEAR);
-		if (!isReset) {
+		if (false == isReset) {
+			final int beginMonthBase0 = beginCal.get(Calendar.MONTH);
+			final int endMonthBase0 = endCal.get(Calendar.MONTH);
+			if (beginMonthBase0 < endMonthBase0) {
+				return result;
+			} else if (beginMonthBase0 > endMonthBase0) {
+				return result - 1;
+			} else if (Calendar.FEBRUARY == beginMonthBase0
+				&& CalendarUtil.isLastDayOfMonth(beginCal)
+				&& CalendarUtil.isLastDayOfMonth(endCal)) {
 				// 考虑闰年的2月情况
-			if (Calendar.FEBRUARY == beginCal.get(Calendar.MONTH) && Calendar.FEBRUARY == endCal.get(Calendar.MONTH)) {
-				if (beginCal.get(Calendar.DAY_OF_MONTH) == beginCal.getActualMaximum(Calendar.DAY_OF_MONTH)
-					&& endCal.get(Calendar.DAY_OF_MONTH) == endCal.getActualMaximum(Calendar.DAY_OF_MONTH)) {
 				// 两个日期都位于2月的最后一天，此时月数按照相等对待，此时都设置为1号
 				beginCal.set(Calendar.DAY_OF_MONTH, 1);
 				endCal.set(Calendar.DAY_OF_MONTH, 1);
 			}
-			}
 
 			endCal.set(Calendar.YEAR, beginCal.get(Calendar.YEAR));
 			final long between = endCal.getTimeInMillis() - beginCal.getTimeInMillis();

hutool-core/src/test/java/org/dromara/hutool/core/date/DateBetweenTest.java

@@ -47,6 +47,40 @@ public class DateBetweenTest {
 		Assertions.assertEquals(18, betweenYear);
 	}
 
+	@Test
+	public void betweenYearTest3(){
+		final String dateStr1 = "2023-02-28 00:00:01";
+		final Date sdate = DateUtil.parse(dateStr1);
+		final String dateStr2 = "2024-02-29 00:00:00";
+		final Date edate = DateUtil.parse(dateStr2);
+
+		final long result = DateUtil.betweenYear(sdate, edate, false);
+		Assertions.assertEquals(0, result);
+	}
+
+	@Test
+	public void betweenYearTest4(){
+		final String dateStr1 = "2024-02-29 00:00:00";
+		final Date sdate = DateUtil.parse(dateStr1);
+		final String dateStr2 = "2025-02-28 00:00:00";
+		final Date edate = DateUtil.parse(dateStr2);
+
+		final long result = DateUtil.betweenYear(sdate, edate, false);
+		Assertions.assertEquals(1, result);
+	}
+
+	@Test
+	public void issueI97U3JTest(){
+		final String dateStr1 = "2024-02-29 23:59:59";
+		final Date sdate = DateUtil.parse(dateStr1);
+
+		final String dateStr2 = "2023-03-01 00:00:00";
+		final Date edate = DateUtil.parse(dateStr2);
+
+		final long result = DateUtil.betweenYear(sdate, edate, false);
+		Assertions.assertEquals(0, result);
+	}
+
 	@Test
 	public void betweenMonthTest() {
 		final Date start = DateUtil.parse("2017-02-01 12:23:46");