byte[]转file，file转MultipartFile

public static File byte2File(byte[] buf, String filePath, String fileName){
    BufferedOutputStream bos = null;
    FileOutputStream fos = null;
    File file = null;
    try{
        File dir = new File(filePath);
        if (!dir.exists() && dir.isDirectory()){
            dir.mkdirs();
        }
        file = new File(filePath + File.separator + fileName);
        fos = new FileOutputStream(file);
        bos = new BufferedOutputStream(fos);
        bos.write(buf);
    }catch (Exception e){
        e.printStackTrace();
    }
    finally{
        if (bos != null){
            try{
                bos.close();
            }catch (IOException e){
                e.printStackTrace();
            }
        }
        if (fos != null){
            try{
                fos.close();
            }catch (IOException e){
                e.printStackTrace();
            }
        }
    }
    return file;
}

public static MultipartFile getMultipartFile(File file){
    FileInputStream fileInputStream = null;
    MultipartFile multipartFile = null;
    try {
        fileInputStream = new FileInputStream(file);
        multipartFile = new MockMultipartFile(file.getName(),file.getName(),
                ContentType.APPLICATION_OCTET_STREAM.toString(),fileInputStream);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return multipartFile;
}