生成签名的逻辑-用于SHA-2散列(Java)

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

public static String generateSHA2Signature(String data) {
    try {
        // 创建SHA-2散列算法的实例
        MessageDigest sha256 = MessageDigest.getInstance("SHA-256");

        // 将数据转换为字节数组
        byte[] bytes = data.getBytes();

        // 计算散列值
        byte[] hash = sha256.digest(bytes);

        // 将散列值转换为十六进制字符串
        StringBuilder hexString = new StringBuilder();
        for (byte b : hash) {
            String hex = Integer.toHexString(0xff & b);
            if (hex.length() == 1) {
                hexString.append('0');
            }
            hexString.append(hex);
        }

        // 返回生成的签名
        return hexString.toString();
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    }

    return null;
}

String data = "要生成签名的数据";
String signature = generateSHA2Signature(data);
System.out.println("SHA-2 Signature: " + signature);