spring如何在java中将MimerReader的内容转换成字符串？

Question

对于SimpleEmailMessage，您只需执行以下操作：

SimpleMailMessage msg = new SimpleMailMessage()
msg.setFrom(..)
msg.setTo(..)
msg.setCc(..)
msg.setSubject(..)
msg.setText(..)

msg.toString()

结果是：

SimpleMailMessage: from=test@email.com; replyTo=null; to=test@email.com; ... text=Test Body;

这是一种很好的方式，可以轻松查看SimpleEmailMessage的内容，但这是在不发送附件的情况下。我有一个我使用的附件功能

MimeMessage message = javaMailSender.createMimeMessage();
MimeMessageHelper helper = new MimeMessageHelper(message, true);
helper.setFrom(from);
helper.setTo(to);
helper.setCc(InternetAddress.parse(cc));
helper.setSubject(subject);
helper.setText(body);
FileSystemResource file = new FileSystemResource(attachmentPath);
helper.addAttachment(fileName, file);

但是当执行helper.toString()或message.toString()时，它只返回java类文本

有没有一种像SimpleEmailMessage那样以字符串格式显示MimeMessage内容的好方法

Answer 1

我可以考虑的一个选项是使用Jackson的ObjectMapper将对象转换为JSON并打印，如下所示：

MimeMessage message = javaMailSender.createMimeMessage();
MimeMessageHelper helper = new MimeMessageHelper(message, true);
helper.setFrom(from);
helper.setTo(to);
helper.setCc(InternetAddress.parse(cc));
helper.setSubject(subject);
helper.setText(body);
FileSystemResource file = new FileSystemResource(attachmentPath);
helper.addAttachment(fileName, file);

ObjectMapper mapper = new ObjectMapper();
String helperAsJson= mapper.writeValueAsString(helper);