package com.fuyuanshen.web.util;

import org.apache.commons.codec.digest.DigestUtils;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.io.InputStream;
import java.security.MessageDigest;
import java.util.HexFormat;

/**
 * 文件哈希工具类
 */
public class FileHashUtil {
    private static final String ALGORITHM = "SHA-256";

    public static String hash(MultipartFile file) throws IOException {
        MessageDigest digest = DigestUtils.getDigest(ALGORITHM);
        try (InputStream in = file.getInputStream()) {
            byte[] buf = new byte[8192];
            int len;
            while ((len = in.read(buf)) != -1) {
                digest.update(buf, 0, len);
            }
        }
        return HexFormat.of().formatHex(digest.digest());
    }
}