Java Create HMAC

gistfile1.txt

import java.net.URLEncoder;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;
/**
* Sign an unsigned URL.
* @param path The URL-encoded path including the leading slash. E.g. "/1.0/account/1/2".
* @param key The access key id of the secret access key to use for creating the
* signature.
* @param expires The time in seconds from the Epoch when the signature expires.
* @param key The secret access key to use for creating the signature.
* @return the URL-encoded path with the signature query string added to the end.
*/
public static String sign(String path, String accesKeyId, Long expires, String key) throws Exception {
// Create the canonical string from expires and path
String canonical = "GET\n\n\n" + expires + "\n" + path;
// Encrypt it with key
byte[] keyBytes = Base64.decodeBase64(key.getBytes("US-ASCII"));
Mac hmac = Mac.getInstance("HmacSHA256");
hmac.init(new SecretKeySpec(keyBytes, "HmacSHA256"));
byte[] signatureBytes = hmac.doFinal(canonical.getBytes("UTF-8"));
// Base64 encode the encrypted results
String signatureBase64 = new String(Base64.encodeBase64(signatureBytes), "US-ASCII");
// URL encode the base64
String signature = URLEncoder.encode(signatureBase64, "UTF-8");
// Assemble the signed URL
return path + "?a1accesskeyid=" + accesKeyId + "&expires="+ expires + "&signature=" + signature;
}