diff --git a/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java b/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
index 2caf771e3..4e7c3dc33 100755
--- a/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
@@ -2560,13 +2560,13 @@ public class CollUtil {
 	/**
 	 * 一个对象不为空且不存在于该集合中时，加入到该集合中<br>
 	 * <pre>
-	 *     null, null => false
-	 *     [], null => false
-	 *     null, "123" => false
-	 *     ["123"], "123" => false
-	 *     [], "123" => true
-	 *     ["456"], "123" => true
-	 *     [Animal{"name": "jack"}], Dog{"name": "jack"} => true
+	 *     null, null -&gt; false
+	 *     [], null -&gt; false
+	 *     null, "123" -&gt; false
+	 *     ["123"], "123" -&gt; false
+	 *     [], "123" -&gt; true
+	 *     ["456"], "123" -&gt; true
+	 *     [Animal{"name": "jack"}], Dog{"name": "jack"} -&gt; true
 	 * </pre>
 	 *
 	 * @param collection 被加入的集合
@@ -2576,7 +2576,7 @@ public class CollUtil {
 	 * @return 是否添加成功
 	 * @author Cloud-Style
 	 */
-	public static <T, S extends T> boolean addIfAbsent(Collection<T> collection, S object) {
+	public static <T, S extends T> boolean addIfAbsent(final Collection<T> collection, final S object) {
 		if (object == null || collection == null || collection.contains(object)) {
 			return false;
 		}
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 cac69d653..b4265ca54 100755
--- a/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/text/CharSequenceUtil.java
@@ -56,6 +56,7 @@ public class CharSequenceUtil extends StrChecker {
 	/**
 	 * 当给定字符串为空字符串时，转换为{@code null}
 	 *
+	 * @param <T> 字符串类型
 	 * @param str 被转换的字符串
 	 * @return 转换后的字符串
 	 */
@@ -129,6 +130,7 @@ public class CharSequenceUtil extends StrChecker {
 	 * @param handler         非blank的处理方法
 	 * @param defaultSupplier 默认值提供者
 	 * @param <T>             对象类型（必须实现CharSequence接口）
+	 * @param <V>             结果类型
 	 * @return 被检查对象为{@code null}返回默认值，否则返回自定义handle处理后的返回值
 	 * @throws NullPointerException {@code defaultValueSupplier == null} 时，抛出
 	 * @since 5.7.20