Java HMAC-SHA1加密算法的实现

public static String hamcsha1(byte[] data, byte[] key)
{
      try {
          SecretKeySpec signingKey = new SecretKeySpec(key, "HmacSHA1");
          Mac mac = Mac.getInstance("HmacSHA1");
          mac.init(signingKey);
          return byte2hex(mac.doFinal(data));
      } catch (NoSuchAlgorithmException e) {
           e.printStackTrace();
      } catch (InvalidKeyException e) {
           e.printStackTrace();
      }
     return null;
 }

 //二行制转字符串
public static String byte2hex(byte[] b)
{
    StringBuilder hs = new StringBuilder();
    String stmp;
    for (int n = 0; b!=null && n < b.length; n++) {
        stmp = Integer.toHexString(b[n] & 0XFF);
        if (stmp.length() == 1)
            hs.append('0');
        hs.append(stmp);
    }
    return hs.toString().toUpperCase();
}