微信支付签名工具

https://pay.weixin.qq.com/wiki/doc/api/micropay.php?chapter=20_1

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

/**
 * 微信签名
 */
public class HMACSHA256 {

    /**
     * 将加密后的字节数组转换成字符串
     *
     * @param b 字节数组
     * @return 字符串
     */
    public static String byteArrayToHexString(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().toLowerCase();
    }

    /**
     * sha256_HMAC加密
     *
     * @param message 消息
     * @param secret  秘钥
     * @return 加密后字符串
     */
    public static String sha256_HMAC(String message, String secret) {
        String hash = "";
        try {
            Mac sha256_HMAC = Mac.getInstance("HmacSHA256");
            SecretKeySpec secret_key = new SecretKeySpec(secret.getBytes(), "HmacSHA256");
            sha256_HMAC.init(secret_key);
            byte[] bytes = sha256_HMAC.doFinal(message.getBytes());
            hash = byteArrayToHexString(bytes);
        } catch (Exception e) {
            System.out.println("Error HmacSHA256 ===========" + e.getMessage());
        }
        return hash;
    }

    public static void main(String[] args) {
        String stringA = "appid=wxd930ea5d5a258f4f&body=test&device_info=1000&mch_id=10000100&nonce_str=ibuaiVcKdpRxkhJA";
        String stringSignTemp = stringA + "&key=192006250b4c09247ec02edce69f6a2d";//注：key为商户平台设置的密钥key
        System.out.println(sha256_HMAC(stringSignTemp, "192006250b4c09247ec02edce69f6a2d").toUpperCase());
        System.out.println("6A9AE1657590FD6257D693A078E1C3E4BB6BA4DC30B23E0EE2496E54170DACD6");
    }

}