HMAC-SHA1 java版

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
 
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
 
public class HMACSHA1 {
 
	private static final String HMAC_SHA1 = "HmacSHA1";
 
	/**
	 * 生成簽名數據
	 * 
	 * @param data
	 *            待加密的數據
	 * @param key
	 *            加密使用的key
	 * @throws InvalidKeyException
	 * @throws NoSuchAlgorithmException
	 */
	public static String getSignature(String data, String key) throws Exception {
		byte[] keyBytes = key.getBytes();
		SecretKeySpec signingKey = new SecretKeySpec(keyBytes, HMAC_SHA1);
		Mac mac = Mac.getInstance(HMAC_SHA1);
		mac.init(signingKey);
		byte[] rawHmac = mac.doFinal(data.getBytes());
		StringBuilder sb = new StringBuilder();
		for (byte b : rawHmac) {
			sb.append(byteToHexString(b));
		}
		return sb.toString();
	}
 
	private static String byteToHexString(byte ib) {
		char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a',
				'b', 'c', 'd', 'e', 'f' };
		char[] ob = new char[2];
		ob[0] = Digit[(ib >>> 4) & 0X0f];
		ob[1] = Digit[ib & 0X0F];
		String s = new String(ob);
		return s;
	}
}