java实现对数据的SHA-256加密算法

以下是Java实现对数据的SHA-256加密算法的示例代码：

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class SHA256Util {
    public static String sha256(String input) {
        try {
            MessageDigest digest = MessageDigest.getInstance("SHA-256");
            byte[] hash = digest.digest(input.getBytes(StandardCharsets.UTF_8));
            StringBuilder hexString = new StringBuilder();
            for (byte b : hash) {
                String hex = Integer.toHexString(0xff & b);
                if (hex.length() == 1) hexString.append('0');
                hexString.append(hex);
            }
            return hexString.toString();
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
    }
}

使用示例：

String input = "hello world";
String sha256 = SHA256Util.sha256(input);
System.out.println(sha256); // 输出：b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9