HMSA-SHA256代码工具类

以下是一个简单的HMSA-SHA256代码工具类示例，你可以根据自己的需要进行修改：

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Base64;

public class HMSSha256Util {

    /**
     * 计算HMSA-SHA256签名
     * @param appSecret 应用的appSecret
     * @param timestamp 当前时间戳
     * @param requestBody 请求体
     * @return 签名字符串
     */
    public static String calculateHmsaSha256(String appSecret, long timestamp, String requestBody) {
        try {
            // 将appSecret和timestamp拼接
            String plainText = appSecret + timestamp;
            // 计算SHA256摘要
            MessageDigest messageDigest = MessageDigest.getInstance("SHA-256");
            byte[] digest = messageDigest.digest(plainText.getBytes());
            // 对摘要进行Base64编码
            String base64Digest = Base64.getEncoder().encodeToString(digest);
            // 将base64编码的摘要和requestBody拼接
            String textToSign = base64Digest + requestBody;
            // 再次计算SHA256摘要
            byte[] finalDigest = messageDigest.digest(textToSign.getBytes());
            // 对最终摘要进行Base64编码，得到签名字符串
            return Base64.getEncoder().encodeToString(finalDigest);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("计算HMSA-SHA256签名出错", e);
        }
    }
}

使用示例：

// 假设appSecret为"testAppSecret"，timestamp为当前时间戳，requestBody为请求体
String appSecret = "testAppSecret";
long timestamp = System.currentTimeMillis() / 1000L;
String requestBody = "{\"name\":\"张三\",\"age\":18}";
String signature = HMSSha256Util.calculateHmsaSha256(appSecret, timestamp, requestBody);
System.out.println(signature);