java - 如何使用 java 邮件将 PDF 嵌入为 INLINE。对于我所做的所有尝试，它是一个附件

Question

InputStream inputStream = new FileInputStream(fileName);

String inputStreamToString = inputStream.toString();

inputStream.close();
ByteArrayInputStream arrayInputStream = new ByteArrayInputStream(inputStreamToString.getBytes());

if (arrayInputStream != null && arrayInputStream instanceof ByteArrayInputStream) {
    // create the second message part with the attachment from a OutputStrean
    MimeBodyPart attachment= new MimeBodyPart();
    ByteArrayDataSource ds = new ByteArrayDataSource(arrayInputStream, "application/pdf"); 
    attachment.setDataHandler(new DataHandler(ds));
    attachment.setDisposition(MimeBodyPart.INLINE);
    attachment.setFileName(fileName);
    multipart.addBodyPart(attachment);
}
mimeMsg.setContent(multipart);

我将 PDF 作为字节获取并使用 ByteArrayDataSource。

我还将处置设置为内联。