diff --git a/hutool-core/src/main/java/cn/hutool/core/codec/BCD.java b/hutool-core/src/main/java/cn/hutool/core/codec/BCD.java
index 6600133cc..b63b79f8c 100644
--- a/hutool-core/src/main/java/cn/hutool/core/codec/BCD.java
+++ b/hutool-core/src/main/java/cn/hutool/core/codec/BCD.java
@@ -17,6 +17,7 @@ public class BCD {
 	 * @return BCD
 	 */
 	public static byte[] strToBcd(String asc) {
+		Assert.notNull(asc, "ASCII must not be null!");
 		int len = asc.length();
 		int mod = len % 2;
 		if (mod != 0) {
diff --git a/hutool-core/src/main/java/cn/hutool/core/codec/Caesar.java b/hutool-core/src/main/java/cn/hutool/core/codec/Caesar.java
index c7c94f40e..d1b5d36f9 100644
--- a/hutool-core/src/main/java/cn/hutool/core/codec/Caesar.java
+++ b/hutool-core/src/main/java/cn/hutool/core/codec/Caesar.java
@@ -1,5 +1,7 @@
 package cn.hutool.core.codec;
 
+import cn.hutool.core.lang.Assert;
+
 /**
  * 凯撒密码实现<br>
  * 算法来自：https://github.com/zhaorenjie110/SymmetricEncryptionAndDecryption
@@ -19,6 +21,7 @@ public class Caesar {
 	 * @return 加密后的内容
 	 */
 	public static String encode(String message, int offset) {
+		Assert.notNull(message, "message must be not null!");
 		final int len = message.length();
 		final char[] plain = message.toCharArray();
 		char c;
@@ -40,6 +43,7 @@ public class Caesar {
 	 * @return 解密后的内容
 	 */
 	public static String decode(String cipherText, int offset) {
+		Assert.notNull(cipherText, "cipherText must be not null!");
 		final int len = cipherText.length();
 		final char[] plain = cipherText.toCharArray();
 		char c;
diff --git a/hutool-core/src/main/java/cn/hutool/core/codec/PercentCodec.java b/hutool-core/src/main/java/cn/hutool/core/codec/PercentCodec.java
index 88fd210a0..9d91cd17d 100755
--- a/hutool-core/src/main/java/cn/hutool/core/codec/PercentCodec.java
+++ b/hutool-core/src/main/java/cn/hutool/core/codec/PercentCodec.java
@@ -1,5 +1,6 @@
 package cn.hutool.core.codec;
 
+import cn.hutool.core.lang.Assert;
 import cn.hutool.core.util.ArrayUtil;
 import cn.hutool.core.util.CharUtil;
 import cn.hutool.core.util.HexUtil;
@@ -51,6 +52,7 @@ public class PercentCodec implements Serializable {
 	 * @return PercentCodec
 	 */
 	public static PercentCodec of(CharSequence chars) {
+		Assert.notNull(chars, "chars must not be null");
 		final PercentCodec codec = new PercentCodec();
 		final int length = chars.length();
 		for (int i = 0; i < length; i++) {
diff --git a/hutool-core/src/main/java/cn/hutool/core/codec/PunyCode.java b/hutool-core/src/main/java/cn/hutool/core/codec/PunyCode.java
index fd3fc3864..c6474a4a0 100644
--- a/hutool-core/src/main/java/cn/hutool/core/codec/PunyCode.java
+++ b/hutool-core/src/main/java/cn/hutool/core/codec/PunyCode.java
@@ -44,6 +44,7 @@ public class PunyCode {
 	 * @throws UtilException 计算异常
 	 */
 	public static String encode(CharSequence input, boolean withPrefix) throws UtilException {
+		Assert.notNull(input, "input must not be null!");
 		int n = INITIAL_N;
 		int delta = 0;
 		int bias = INITIAL_BIAS;
@@ -126,6 +127,7 @@ public class PunyCode {
 	 * @throws UtilException 计算异常
 	 */
 	public static String decode(String input) throws UtilException {
+		Assert.notNull(input, "input must not be null!");
 		input = StrUtil.removePrefixIgnoreCase(input, PUNY_CODE_PREFIX);
 
 		int n = INITIAL_N;
diff --git a/hutool-core/src/main/java/cn/hutool/core/codec/Rot.java b/hutool-core/src/main/java/cn/hutool/core/codec/Rot.java
index ff0cdd135..d0826aee1 100644
--- a/hutool-core/src/main/java/cn/hutool/core/codec/Rot.java
+++ b/hutool-core/src/main/java/cn/hutool/core/codec/Rot.java
@@ -1,5 +1,7 @@
 package cn.hutool.core.codec;
 
+import cn.hutool.core.lang.Assert;
+
 /**
  * RotN（rotate by N places），回转N位密码，是一种简易的替换式密码，也是过去在古罗马开发的凯撒加密的一种变体。<br>
  * 代码来自：https://github.com/orclight/jencrypt
@@ -30,11 +32,11 @@ public class Rot {
 	 * Rot-13编码
 	 *
 	 * @param message 被编码的消息
-	 * @param isEnocdeNumber 是否编码数字
+	 * @param isEncodeNumber 是否编码数字
 	 * @return 编码后的字符串
 	 */
-	public static String encode13(String message, boolean isEnocdeNumber) {
-		return encode(message, 13, isEnocdeNumber);
+	public static String encode13(String message, boolean isEncodeNumber) {
+		return encode(message, 13, isEncodeNumber);
 	}
 
 	/**
@@ -42,15 +44,16 @@ public class Rot {
 	 *
 	 * @param message 被编码的消息
 	 * @param offset 位移，常用位移13
-	 * @param isEnocdeNumber 是否编码数字
+	 * @param isEncodeNumber 是否编码数字
 	 * @return 编码后的字符串
 	 */
-	public static String encode(String message, int offset, boolean isEnocdeNumber) {
+	public static String encode(String message, int offset, boolean isEncodeNumber) {
+		Assert.notNull(message, "message must not be null");
 		final int len = message.length();
 		final char[] chars = new char[len];
 
 		for (int i = 0; i < len; i++) {
-			chars[i] = encodeChar(message.charAt(i), offset, isEnocdeNumber);
+			chars[i] = encodeChar(message.charAt(i), offset, isEncodeNumber);
 		}
 		return new String(chars);
 	}
@@ -85,6 +88,7 @@ public class Rot {
 	 * @return 解码后的字符串
 	 */
 	public static String decode(String rot, int offset, boolean isDecodeNumber) {
+		Assert.notNull(rot, "rot must not be null");
 		final int len = rot.length();
 		final char[] chars = new char[len];