java - FileSystemResource : java. io.FileNotFoundException

Question

我尝试从 URL(我的 DropBox 帐户)创建如下所示的 fil，然后将其作为附件添加到 MimeMessageHelper，但我收到 FileNotFoundException。我可能做错了什么？

String[] attachments = {"https://dl.dropboxusercontent.com/s/XXXX/my%20Letter.docx"};

for (String attachment : attachments) {
    FileSystemResource file = new FileSystemResource("url:" + attachment);
    message.addAttachment(file.getFilename(), file);
}

错误:

Caused by: org.springframework.mail.MailSendException: Failed messages: javax.mail.MessagingException: IOException while sending message;
  nested exception is:
    java.io.FileNotFoundException: url:https:\dl.dropboxusercontent.com\s\XXXX\my%20Letter.docx (The filename, directory name, or volume label syntax is incorrect); message exceptions (1) are:
Failed message 1: javax.mail.MessagingException: IOException while sending message;
  nested exception is:
    java.io.FileNotFoundException: url:https:\dl.dropboxusercontent.com\s\XXXX\my%20Letter.docx (The filename, directory name, or volume label syntax is incorrect)

<小时/>

更新:

如何从 Http URL 创建 FileSystemResource？

Answer 1

您可以使用 UrlResource 代替文件系统资源，或者使用某些 http 客户端下载文件，然后将其附加到电子邮件中。

例如:

URL website = new URL("http://someurl");
ReadableByteChannel rbc = Channels.newChannel(website.openStream());
FileOutputStream fos = new FileOutputStream("some temporary name");
fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);

然后使用FileSystemResource附加它

您可以使用 http 客户端来实现此目的，例如:okhttp