Java工具类(文件)

            package
             com.ruhuanxingyun.javabasic.util;


            import
             org.springframework.web.multipart.MultipartFile;


            import
             java.math.BigInteger;

            import
             java.security.MessageDigest;

            import
             java.util.Arrays;


            /**
            
 * @description: 文件工具类
 * 
            @author
            : ruphie
 * @date: Create in 2020/7/7 23:07
 * @company: ruhuanxingyun
 
            */
            public
            class
             FileUtils {

    
            private
            static
            final
            int SPLIT_SIZE = 10 * 1024 * 1024;

    /**
     * 获取文件MD5值
     *
     * @param file 文件
     * @return MD5
     */publicstatic String getFileMd5(MultipartFile file) {
        try {
            byte[] bytes = file.getBytes();
            MessageDigest messageDigest = MessageDigest.getInstance("MD5");
            byte[] digest = messageDigest.digest(bytes);

            returnnew BigInteger(1, digest).toString(16);
        } catch (Exception e) {
            e.printStackTrace();

            returnnull;
        }
    }

    /**
     * 文件字节分割
     *
     * @param bytes 字节
     * @return 字节数组
     */publicstaticbyte[][] splitBytes(byte[] bytes) {
        int bytesLen = bytes.length;
        int arrayLen = (int) Math.ceil(bytesLen / SPLIT_SIZE);
        byte[][] bytesArr = newbyte[arrayLen][];
        int from, to;
        for (int i = 0; i < arrayLen; i++) {
            from = i * SPLIT_SIZE;
            to = from + SPLIT_SIZE;
            if (to > bytesLen) {
                to = bytesLen;
            }
            bytesArr[i] = Arrays.copyOfRange(bytes, from, to);
        }

        return bytesArr;
    }

}