diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/impl/SnowFlakeIDKeyGenerator.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/impl/SnowFlakeIDKeyGenerator.java
index 73a9b17f..7850ab20 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/impl/SnowFlakeIDKeyGenerator.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/keygen/impl/SnowFlakeIDKeyGenerator.java
@@ -1,3 +1,18 @@
+/**
+ * Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 package com.mybatisflex.core.keygen.impl;
 
 import com.mybatisflex.core.exception.FlexExceptions;