如何在android生成的加密签名中添加时间戳

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SignatureGenerator {
    public static String generateSignature(String data) {
        // 获取当前时间戳
        long timestamp = System.currentTimeMillis();

        // 拼接数据和时间戳
        String signatureData = data + timestamp;

        try {
            // 创建SHA-256加密算法实例
            MessageDigest digest = MessageDigest.getInstance("SHA-256");

            // 对签名数据进行加密
            byte[] encryptedBytes = digest.digest(signatureData.getBytes());

            // 将加密后的字节数组转换为十六进制字符串
            StringBuilder sb = new StringBuilder();
            for (byte b : encryptedBytes) {
                sb.append(String.format("%02x", b));
            }

            // 返回加密签名
            return sb.toString();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }

        return null;
    }
}