package com.gh.common.util;

import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;

public class HMACUtils {

    public static String encrypt(String data, String key) {
        try {
            SecretKeySpec signingKey = new SecretKeySpec(key.getBytes(), "HmacSHA256");
            Mac mac = Mac.getInstance("HmacSHA256");
            mac.init(signingKey);
            return byte2hex(mac.doFinal(data.getBytes()));
        } catch (NoSuchAlgorithmException | InvalidKeyException e) {
            e.printStackTrace();
        }
        return null;
    }

    private static String byte2hex(byte[] ciphertext) {
        StringBuilder builder = new StringBuilder();
        String stmp;
        for (int i = 0; ciphertext != null && i < ciphertext.length; i++) {
            stmp = Integer.toHexString(ciphertext[i] & 0XFF);
            if (stmp.length() == 1) {
                builder.append('0');
            }
            builder.append(stmp);
        }
        return builder.toString().toLowerCase();
    }

}