add null check

hutool-core/src/main/java/cn/hutool/core/codec/BCD.java

@@ -1,5 +1,7 @@
 package cn.hutool.core.codec;
 
+import cn.hutool.core.lang.Assert;
+
 /**
  * BCD码（Binary-Coded Decimal‎）亦称二进码十进数或二-十进制代码<br>
  * BCD码这种编码形式利用了四个位元来储存一个十进制的数码，使二进制和十进制之间的转换得以快捷的进行<br>
@@ -58,6 +60,7 @@ public class BCD {
 	 * @return BCD
 	 */
 	public static byte[] ascToBcd(byte[] ascii) {
+		Assert.notNull(ascii, "Ascii must be not null!");
 		return ascToBcd(ascii, ascii.length);
 	}
 
@@ -68,6 +71,7 @@ public class BCD {
 	 * @return BCD
 	 */
 	public static byte[] ascToBcd(byte[] ascii, int ascLength) {
+		Assert.notNull(ascii, "Ascii must be not null!");
 		byte[] bcd = new byte[ascLength / 2];
 		int j = 0;
 		for (int i = 0; i < (ascLength + 1) / 2; i++) {
@@ -83,6 +87,7 @@ public class BCD {
 	 * @return ASCII字符串
 	 */
 	public static String bcdToStr(byte[] bytes) {
+		Assert.notNull(bytes, "Bcd bytes must be not null!");
 		char[] temp = new char[bytes.length * 2];
 		char val;