使用 spring 引导发送电子邮件时文件名显示不正确

Question

我在发送 email 时遇到一个问题，其文件名包含重音符号和特殊字符（-、_、*、..） - 它没有以正确的方式显示。

这是我的代码

 @Override
    public boolean sendMail(MailDTO mail,MultipartFile cin, MultipartFile virement, MultipartFile registreC) throws MessagingException, IOException, TemplateException {

        MimeMessage message = mailSender.createMimeMessage();
        MimeMessageHelper helper = new MimeMessageHelper(message,
                MimeMessageHelper.MULTIPART_MODE_MIXED_RELATED);
        System.setProperty("mail.mime.charset", "utf8");


        Map<String,Object> mailToMap = (Map<String, Object>) mail.getMessage();

        Map model = new HashMap<String,Object>();
        model.put("subject", mail.getSubject());
        model.put("firstForm",mailToMap.get("firstForm"));
        model.put("secondForm",mailToMap.get("secondForm"));
        model.put("thirdForm",mailToMap.get("thirdForm"));
        model.put("fourthForm",mailToMap.get("fourthForm"));
        model.put("fifthForm",mailToMap.get("fifthForm"));
        model.put("sixthForm",mailToMap.get("sixthForm"));
        model.put("montant",mailToMap.get("total"));
        

        Template t = freemarkerConfig.getTemplate("email-template.ftl");
        String html = FreeMarkerTemplateUtils.processTemplateIntoString(t,model);
        helper.setTo(new String[]{"aa@mail.com"});

        helper.setText(html, true);
        helper.setSubject(mail.getSubject());
        
        String f1 = MimeUtility.encodeWord(cin.getOriginalFilename());
        String f2 = MimeUtility.encodeWord(virement.getOriginalFilename());
        String f3 = MimeUtility.encodeWord(registreC.getOriginalFilename());
        
        helper.addAttachment(f1,new ByteArrayResource(cin.getBytes()));
        helper.addAttachment(f2,new ByteArrayResource(virement.getBytes()));
        helper.addAttachment(f3,new ByteArrayResource(registreC.getBytes()));

        mailSender.send(message);
        return true;

    }