Merge branch 'v5-dev' of gitee.com:dromara/hutool into v5-dev

hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java

@@ -2247,6 +2247,26 @@ public class DateUtil extends CalendarUtil {
 		return startTime.before(realEndTime) && endTime.after(realStartTime);
 	}
 
+	/**
+	 * 是否为本月最后一天
+	 * @param dateTime {@link DateTime}
+	 * @return 是否为本月最后一天
+	 * @since 5.8.8
+	 */
+	public static boolean isLastDayOfMonth(DateTime dateTime){
+		return dateTime.dayOfMonth()==getLastDayOfMonth(dateTime);
+	}
+
+	/**
+	 * 获得本月的最后一天
+	 * @param dateTime {@link DateTime}
+	 * @return 天
+	 * @since 5.8.8
+	 */
+	public static int getLastDayOfMonth(DateTime dateTime){
+		return Month.getLastDay(dateTime.month(),dateTime.isLeapYear());
+	}
+
 	// ------------------------------------------------------------------------ Private method start
 
 	/**

hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java

@@ -1094,4 +1094,12 @@ public class DateUtilTest {
 				DateUtil.parse(sourceStr));
 		Assert.assertTrue(between);
 	}
+
+	@Test
+	public void isLastDayTest(){
+		DateTime dateTime = DateUtil.parse("2022-09-30");
+		int dayOfMonth  = DateUtil.getLastDayOfMonth(dateTime);
+		Assert.assertEquals(dayOfMonth,dateTime.dayOfMonth());
+		Assert.assertTrue("not is last day of this month !!",DateUtil.isLastDayOfMonth(dateTime));
+	}
 }