如何使用InputStream和Spring发送带有附件的电子邮件？

情况是这样的：

首先，我们在内存中生成一个文件，我们可以获得 InputStream 对象。
第二个 InputStream 对象必须作为电子邮件的附件发送。语言是Java，我们使用Spring发送电子邮件。

First, we generate a file in the memory, we can get a InputStream object. Second the InputStream object must be send as a attachment of a email. The language is Java, we use Spring to send email.

我发现了很多信息，但是我找不到如何使用 InputStream 。我尝试这样做：

I have found a lot of information, but I cannot find how to send an email attachment using InputStream. I try to do like this:

InputStreamSource iss= new InputStreamResource(new FileInputStream("c:\\a.txt"));
MimeMessageHelper message = new MimeMessageHelper(mimeMessage, true, "UTF-8");
message.addAttachment("attachment", iss);

但我有一个例外：

传入的资源包含一个开放的流：无效的参数。 JavaMail
需要一个InputStreamSource来为每个
调用创建一个新流。

Passed-in Resource contains an open stream: invalid argument. JavaMail requires an InputStreamSource that creates a fresh stream for every call.