From ee12875bf33320b0f92a2821984b764d0c494c8b Mon Sep 17 00:00:00 2001
From: quping <1607476532@qq.com>
Date: Wed, 28 Sep 2022 18:07:27 +0800
Subject: [PATCH] =?UTF-8?q?=E6=96=B0=E5=A2=9E=E4=BA=86=E8=8E=B7=E5=8F=96?=
 =?UTF-8?q?=E6=9C=AC=E6=9C=88=E6=9C=80=E5=90=8E=E4=B8=80=E5=A4=A9,?=
 =?UTF-8?q?=E6=98=AF=E5=90=A6=E4=B8=BA=E6=9C=AC=E6=9C=88=E6=9C=80=E5=90=8E?=
 =?UTF-8?q?=E4=B8=80=E5=A4=A9?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../java/cn/hutool/core/date/DateUtil.java    | 20 +++++++++++++++++++
 .../cn/hutool/core/date/DateUtilTest.java     |  8 ++++++++
 2 files changed, 28 insertions(+)

diff --git a/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java b/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java
index c1659ea63..ada42c78c 100755
--- a/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java
+++ b/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
 
 	/**
diff --git a/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java
index d7ab1922c..4999287f5 100755
--- a/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java
+++ b/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));
+	}
 }