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 a81d2af2a..2347b18ba 100644
--- a/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java
@@ -18,6 +18,7 @@ import java.text.SimpleDateFormat;
 import java.time.Instant;
 import java.time.LocalDateTime;
 import java.time.Year;
+import java.time.ZoneId;
 import java.time.format.DateTimeFormatter;
 import java.time.temporal.TemporalAccessor;
 import java.util.Calendar;
@@ -481,7 +482,7 @@ public class DateUtil extends CalendarUtil {
 	 * 根据特定格式格式化日期
 	 *
 	 * @param date   被格式化的日期
-	 * @param format 日期格式，常用格式见： {@link DatePattern}
+	 * @param format 日期格式，常用格式见： {@link DatePattern} {@link DatePattern#NORM_DATETIME_PATTERN}
 	 * @return 格式化后的字符串
 	 */
 	public static String format(Date date, String format) {
@@ -505,7 +506,7 @@ public class DateUtil extends CalendarUtil {
 	 * 根据特定格式格式化日期
 	 *
 	 * @param date   被格式化的日期
-	 * @param format {@link DatePrinter} 或 {@link FastDateFormat}
+	 * @param format {@link DatePrinter} 或 {@link FastDateFormat} {@link DatePattern#NORM_DATETIME_FORMAT}
 	 * @return 格式化后的字符串
 	 */
 	public static String format(Date date, DatePrinter format) {
@@ -533,7 +534,7 @@ public class DateUtil extends CalendarUtil {
 	 * 根据特定格式格式化日期
 	 *
 	 * @param date   被格式化的日期
-	 * @param format {@link SimpleDateFormat}
+	 * @param format {@link SimpleDateFormat} {@link DatePattern#NORM_DATETIME_FORMATTER}
 	 * @return 格式化后的字符串
 	 * @since 5.0.0
 	 */
@@ -541,6 +542,10 @@ public class DateUtil extends CalendarUtil {
 		if (null == format || null == date) {
 			return null;
 		}
+		// java.time.temporal.UnsupportedTemporalTypeException: Unsupported field: YearOfEra
+		if (format.getZone() == null) {
+			format = format.withZone(ZoneId.systemDefault());
+		}
 		return format.format(date.toInstant());
 	}
 
@@ -880,7 +885,7 @@ public class DateUtil extends CalendarUtil {
 	 * <li>yyyy-MM-dd'T'HH:mm:ss.SSSZ</li>
 	 * </ol>
 	 *
-	 * @param dateCharSequence 日期字符串
+	 * @param dateCharSequence 日期字符串; 常量如 {@link DatePattern#NORM_DATE_PATTERN}, {@link DatePattern#NORM_DATETIME_PATTERN}
 	 * @return 日期
 	 */
 	public static DateTime parse(CharSequence dateCharSequence) {
diff --git a/hutool-core/src/main/java/cn/hutool/core/date/LocalDateTimeUtil.java b/hutool-core/src/main/java/cn/hutool/core/date/LocalDateTimeUtil.java
index a40065243..66ffb40f5 100644
--- a/hutool-core/src/main/java/cn/hutool/core/date/LocalDateTimeUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/date/LocalDateTimeUtil.java
@@ -373,7 +373,7 @@ public class LocalDateTimeUtil {
 	 * 格式化日期时间为指定格式
 	 *
 	 * @param date      {@link LocalDate}
-	 * @param formatter 日期格式化器，预定义的格式见：{@link DateTimeFormatter}
+	 * @param formatter 日期格式化器，预定义的格式见：{@link DateTimeFormatter}; 常量如： {@link DatePattern#NORM_DATE_FORMATTER}, {@link DatePattern#NORM_DATETIME_FORMATTER}
 	 * @return 格式化后的字符串
 	 * @since 5.3.10
 	 */
@@ -385,7 +385,7 @@ public class LocalDateTimeUtil {
 	 * 格式化日期时间为指定格式
 	 *
 	 * @param date   {@link LocalDate}
-	 * @param format 日期格式，类似于yyyy-MM-dd
+	 * @param format 日期格式，类似于yyyy-MM-dd, 常量如 {@link DatePattern#NORM_DATE_PATTERN}, {@link DatePattern#NORM_DATETIME_PATTERN}
 	 * @return 格式化后的字符串
 	 * @since 5.3.10
 	 */
diff --git a/hutool-core/src/main/java/cn/hutool/core/net/Ipv4Util.java b/hutool-core/src/main/java/cn/hutool/core/net/Ipv4Util.java
index 881670159..3b6ab8140 100644
--- a/hutool-core/src/main/java/cn/hutool/core/net/Ipv4Util.java
+++ b/hutool-core/src/main/java/cn/hutool/core/net/Ipv4Util.java
@@ -148,7 +148,7 @@ public class Ipv4Util {
 
 	/**
 	 * 根据ip地址(xxx.xxx.xxx.xxx)计算出long型的数据
-	 *
+	 * 方法别名：inet_aton
 	 * @param strIP IP V4 地址
 	 * @return long值
 	 */
@@ -160,7 +160,7 @@ public class Ipv4Util {
 
 	/**
 	 * 根据 ip/掩码位 计算IP段的起始IP（字符串型）
-	 *
+	 * 方法别名：inet_ntoa
 	 * @param ip      给定的IP，如218.240.38.69
 	 * @param maskBit 给定的掩码位，如30
 	 * @return 起始IP的字符串表示
diff --git a/hutool-core/src/main/java/cn/hutool/core/text/CharPool.java b/hutool-core/src/main/java/cn/hutool/core/text/CharPool.java
index 06b922a73..228f02209 100644
--- a/hutool-core/src/main/java/cn/hutool/core/text/CharPool.java
+++ b/hutool-core/src/main/java/cn/hutool/core/text/CharPool.java
@@ -2,7 +2,7 @@ package cn.hutool.core.text;
 
 /**
  * 常用字符常量
- *
+ * @see StrPool
  * @author looly
  * @since 5.6.3
  */
diff --git a/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java b/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
index a86d1ef6e..9327a6a44 100644
--- a/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
@@ -4260,7 +4260,7 @@ public class CharSequenceUtil {
 	/**
 	 * 以 conjunction 为分隔符将多个对象转换为字符串
 	 *
-	 * @param conjunction 分隔符
+	 * @param conjunction 分隔符 {@link StrPool#COMMA}
 	 * @param objs        数组
 	 * @return 连接后的字符串
 	 * @see ArrayUtil#join(Object, CharSequence)
@@ -4273,7 +4273,7 @@ public class CharSequenceUtil {
 	 * 以 conjunction 为分隔符将多个对象转换为字符串
 	 *
 	 * @param <T> 元素类型
-	 * @param conjunction 分隔符
+	 * @param conjunction 分隔符 {@link StrPool#COMMA}
 	 * @param iterable    集合
 	 * @return 连接后的字符串
 	 * @see CollUtil#join(Iterable, CharSequence)
diff --git a/hutool-core/src/main/java/cn/hutool/core/text/StrPool.java b/hutool-core/src/main/java/cn/hutool/core/text/StrPool.java
index 2a90f7879..743c4e474 100644
--- a/hutool-core/src/main/java/cn/hutool/core/text/StrPool.java
+++ b/hutool-core/src/main/java/cn/hutool/core/text/StrPool.java
@@ -4,6 +4,7 @@ import cn.hutool.core.util.XmlUtil;
 
 /**
  * 常用字符串常量定义
+ * @see CharPool
  *
  * @author looly
  * @since 5.6.3
diff --git a/hutool-core/src/test/java/cn/hutool/core/convert/NumberChineseFormatterTest.java b/hutool-core/src/test/java/cn/hutool/core/convert/NumberChineseFormatterTest.java
index 3fce2769c..72fe79008 100644
--- a/hutool-core/src/test/java/cn/hutool/core/convert/NumberChineseFormatterTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/convert/NumberChineseFormatterTest.java
@@ -7,6 +7,8 @@ public class NumberChineseFormatterTest {
 
 	@Test
 	public void formatTest() {
+		String f0 = NumberChineseFormatter.format(50008000, false);
+		Assert.assertEquals("五千万零8千", f0);
 		String f1 = NumberChineseFormatter.format(10889.72356, false);
 		Assert.assertEquals("一万零八百八十九点七二", f1);
 		f1 = NumberChineseFormatter.format(12653, false);
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 d80795466..3d8b0172a 100644
--- a/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java
@@ -13,14 +13,7 @@ import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
 import java.time.format.DateTimeFormatter;
-import java.util.ArrayList;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.LinkedHashSet;
-import java.util.List;
-import java.util.Locale;
-import java.util.Objects;
-import java.util.TimeZone;
+import java.util.*;
 
 /**
  * 时间工具单元测试<br>
@@ -893,4 +886,15 @@ public class DateUtilTest {
 		// 在日期格式不匹配的时候，测试是否正常报错
 		DateUtil.parse("2020-12-23", DatePattern.PURE_DATE_PATTERN);
 	}
+
+	@Test
+	public void formatTest(){
+		Calendar calendar = new GregorianCalendar();
+		calendar.set(2021, Calendar.JULY, 14, 23, 59, 59);
+		Date date = new DateTime(calendar);
+
+		Assert.assertEquals("2021-07-14 23:59:59", DateUtil.format(date, DatePattern.NORM_DATETIME_FORMATTER));
+		Assert.assertEquals("2021-07-14 23:59:59", DateUtil.format(date, DatePattern.NORM_DATETIME_FORMAT));
+		Assert.assertEquals("2021-07-14 23:59:59", DateUtil.format(date, DatePattern.NORM_DATETIME_PATTERN));
+	}
 }