Java如何将MultipartFile与File格式互转来一个工具类

以下是一个工具类，可以将MultipartFile和File格式互转：

import org.springframework.web.multipart.MultipartFile;
import java.io.*;

public class FileUtil {

    /**
     * MultipartFile 转 File
     *
     * @param multipartFile
     * @return
     * @throws Exception
     */
    public static File multipartFileToFile(MultipartFile multipartFile) throws Exception {
        File file = new File(multipartFile.getOriginalFilename());
        multipartFile.transferTo(file);
        return file;
    }

    /**
     * File 转 MultipartFile
     *
     * @param file
     * @return
     * @throws Exception
     */
    public static MultipartFile fileToMultipartFile(File file) throws Exception {
        FileInputStream fileInputStream = new FileInputStream(file);
        byte[] bytes = new byte[(int) file.length()];
        fileInputStream.read(bytes);
        return new MockMultipartFile(file.getName(), bytes);
    }
}

具体使用方法如下：

// MultipartFile 转 File
MultipartFile multipartFile = ...;
File file = FileUtil.multipartFileToFile(multipartFile);

// File 转 MultipartFile
File file = ...;
MultipartFile multipartFile = FileUtil.fileToMultipartFile(file);
``