Java____利用自带包用MD5加密__关于图片上传的思考

package com.java.test;
import java.security.MessageDigest;

public class md5 {
public final static String MD5(String s) {
char hexDigits[]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
try {
byte[] btInput = s.getBytes();
System.out.println(btInput);

// 获得MD5摘要算法的 MessageDigest 对象
MessageDigest mdInst = MessageDigest.getInstance("MD5");
// 使用指定的字节更新摘要
mdInst.update(btInput);
// 获得密文
byte[] md = mdInst.digest();
System.out.println("md="+md);

// 把密文转换成十六进制的字符串形式
int j = md.length;
char str[] = new char[j * 2];
int k = 0;
for (int i = 0; i < j; i++) {
byte byte0 = md[i];
str[k++] = hexDigits[byte0 >>> 4 & 0xf];
str[k++] = hexDigits[byte0 & 0xf];
}
return new String(str);
} catch (Exception e) {
e.printStackTrace();
return null;
}
}
public static void main(String[] args) {
//        System.out.println(btInput);

System.out.println(md5.MD5("20121221"));
System.out.println(md5.MD5("加密"));
}
}

[B@de6ced
md=[B@61de33
1F69B3D54C2F95A014EA3CC131A34D5B
[B@14318bb
md=[B@ca0b6
2C8DA3BF709F09E73EC143BA0F9AFC82