如何在使用Java Mail保存附件时加快时间？ [英] How to speed up time when using Java Mail to save attachments?

问题描述

我将 Message msg 分成 Multipart multi1 =（Multipart）msg.getContent（）。
邮件附件在一个BodyPart中， Part part = multi1.getBodyPart（i）;
然后我想保存附件。

I separate Message msg into Multipart multi1 = (Multipart) msg.getContent(). And a mail attachment is in one BodyPart, Part part = multi1.getBodyPart(i); Then I want to save the attachment.

private void saveFile(String fileName, InputStream in) throws IOException {
File file = new File(fileName);
if (!file.exists()) {
  OutputStream out = null;
  try {
    out = new BufferedOutputStream(new FileOutputStream(file));
    in = new BufferedInputStream(in);
    byte[] buf = new byte[BUFFSIZE];
    int len;
    while ((len = in.read(buf)) > 0) {
      out.write(buf, 0, len);
    }
  } catch (FileNotFoundException e) {
    LOG.error(e.toString());
  } finally {
    // close streams
    if (in != null) {
      in.close();
    }
    if (out != null) {
      out.close();
    }
  }
}

但是花费太多时间阅读IO Stream。例如，2.7M文件需要大约160秒才能保存在磁盘上。我已经尝试过Channel和其他一些IO Stream，但没有任何改变。使用Java Mail保存附件的任何解决方案？

But it cost too much time on reading IO Stream. For example,a 2.7M file needs almost 160 seconds to save on the disk. I have already tried Channel and some other IO Stream, but nothing changed. Any solution for saving attachment using Java Mail?

有关更多代码信息 https://github.com/cainzhong/java-mail-demo/blob/master/src/main /java/com/java/mail/impl/ReceiveMailImpl.java

推荐答案

实际上，mail.imaps.partialfetch生效并加速很多。我以前的代码有一个错误。

Actually, mail.imaps.partialfetch takes effect and speeds up a lot. There is a mistake for my previous code.

props.put("mail.imap.partialfetch","false");
props.put("mail.imap.fetchsize", "1048576"); 
props.put("mail.imaps.partialfetch", "false"); 
props.put("mail.imaps.fetchsize", "1048576"); 

而不是

props.put("mail.imap.partialfetch",false);
props.put("mail.imap.fetchsize", "1048576"); 
props.put("mail.imaps.partialfetch", false); 
props.put("mail.imaps.fetchsize", "1048576"); 

在false上加上引号很重要。如果没有，参数将不起作用。

It is important to put a quotation mark on "false". If not, the parameters will not take effects.

无论如何，多亏Bill Billnon。

Anyway, thanks to Bill Shannon.

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