分类:
2008-10-28 18:17:14
的MessageDigest 提供了生产MD5的算法,但是它返回的是byte[],以下方法实现了MD5值为16进制字符串的返回值。
由于没有找到现成的转换方法,采用的是对每个字节比较来实现的.
public class MD5Security {
private final static char[] hexDigits = { '0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
private static String bytesToHex(byte[] bytes) {
StringBuffer sb = new StringBuffer();
int t;
for (int i = 0; i < 16; i++) {// 16 == bytes.length;
t = bytes[i];
if (t < 0)
t +=256;
sb.append(hexDigits[(t >>> 4)]);
sb.append(hexDigits[(t % 16)]);
}
return sb.toString();
}
public static String code(String input) throws Exception {
try {
MessageDigest md = MessageDigest.getInstance(System.getProperty(
"MD5.algorithm", "MD5"));
return bytesToHex(md.digest(input.getBytes("utf-8")));
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
throw new Exception("Could not found MD5 algorithm.", e);
}
}
}