使用JavaMail 1.4仅从电子邮件下载附件

我尝试从电子邮件下载附件时遇到以下代码，下一个错误是无法连接到邮件存储。有人要帮忙吗

*错误

运行：

*代码

---

我使用类似的代码，可以连接javamail-samples.zip中的see代码示例，例如msgshow.java：

  Properties props = System.getProperties();
  props.setProperty("mail.pop3.socketFactory.class","javax.net.ssl.SSLSocketFactory");
  props.setProperty("mail.pop3.socketFactory.fallback", "false");
  props.setProperty("mail.pop3.socketFactory.port",String.valueOf(port));

  Session session = Session.getInstance(props, null);

  Store store = null;
  store = session.getStore(protocol); // protocol is e.g. "pop3" or "imap"

  store.connect(host, port, user, password);

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

    package net.mail;
    import java.io.File;
    import java.io.IOException;
    import java.util.Properties;

    import javax.mail.Address;
    import javax.mail.Folder;
    import javax.mail.Message;
    import javax.mail.MessagingException;
    import javax.mail.Multipart;
    import javax.mail.NoSuchProviderException;
    import javax.mail.Part;
    import javax.mail.Session;
    import javax.mail.Store;
    import javax.mail.internet.MimeBodyPart;


    public class EmailAttachmentReceiver {
    private String saveDirectory;

    /**
     * Sets the directory where attached files will be stored.
     * @param dir absolute path of the directory
     */
    public void setSaveDirectory(String dir) {
        this.saveDirectory = dir;
    }

    /**
     * Downloads new messages and saves attachments to disk if any.
     * @param host
     * @param port
     * @param userName
     * @param password
     */
    public void downloadEmailAttachments(String host, String port,
            String userName, String password) {
        Properties properties = new Properties();

        // server setting
        properties.put("mail.pop3.host", host);
        properties.put("mail.pop3.port", port);

        // SSL setting
        properties.setProperty("mail.pop3.socketFactory.class",
                "javax.net.ssl.SSLSocketFactory");
        properties.setProperty("mail.pop3.socketFactory.fallback", "false");
        properties.setProperty("mail.pop3.socketFactory.port",
                String.valueOf(port));

        Session session = Session.getDefaultInstance(properties);

        try {
            // connects to the message store
            Store store = session.getStore("pop3");
            store.connect(userName, password);

            // opens the inbox folder
            Folder folderInbox = store.getFolder("INBOX");
            folderInbox.open(Folder.READ_ONLY);

            // fetches new messages from server
            Message[] arrayMessages = folderInbox.getMessages();

            for (int i = 0; i < arrayMessages.length; i++) {
                Message message = arrayMessages[i];
                Address[] fromAddress = message.getFrom();
                String from = fromAddress[0].toString();
                String subject = message.getSubject();
                String sentDate = message.getSentDate().toString();

                String contentType = message.getContentType();
                String messageContent = "";

                // store attachment file name, separated by comma
                String attachFiles = "";

                if (contentType.contains("multipart")) {
                    // content may contain attachments
                    Multipart multiPart = (Multipart) message.getContent();
                    int numberOfParts = multiPart.getCount();
                    for (int partCount = 0; partCount < numberOfParts; partCount++) {
                        MimeBodyPart part = (MimeBodyPart)          multiPart.getBodyPart(partCount);
                        if (Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition())) {
                            // this part is attachment
                            String fileName = part.getFileName();
                            attachFiles += fileName + ", ";
                            part.saveFile(saveDirectory + File.separator + fileName);
                        } else {
                            // this part may be the message content
                            messageContent = part.getContent().toString();
                        }
                    }

                    if (attachFiles.length() > 1) {
                        attachFiles = attachFiles.substring(0, attachFiles.length() - 2);
                    }
                } else if (contentType.contains("text/plain")
                        || contentType.contains("text/html")) {
                    Object content = message.getContent();
                    if (content != null) {
                        messageContent = content.toString();
                    }
                }

                // print out details of each message
                System.out.println("Message #" + (i + 1) + ":");
                System.out.println("\t From: " + from);
                System.out.println("\t Subject: " + subject);
                System.out.println("\t Sent Date: " + sentDate);
                System.out.println("\t Message: " + messageContent);
                System.out.println("\t Attachments: " + attachFiles);
            }

            // disconnect
            folderInbox.close(false);
            store.close();
        } catch (NoSuchProviderException ex) {
            System.out.println("No provider for pop3.");
            ex.printStackTrace();
        } catch (MessagingException ex) {
            System.out.println("Could not connect to the message store");
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    /**
     * Runs this program with Gmail POP3 server
     */
    public static void main(String[] args) {
        String host = "pop.gmail.com";
        String port = "995";
        String userName = "username";
        String password = "password";

        String saveDirectory = "D:/Attachment";

        EmailAttachmentReceiver receiver = new EmailAttachmentReceiver();
        receiver.setSaveDirectory(saveDirectory);
        receiver.downloadEmailAttachments(host, port, userName, password);

    }
}

  Properties props = System.getProperties();
  props.setProperty("mail.pop3.socketFactory.class","javax.net.ssl.SSLSocketFactory");
  props.setProperty("mail.pop3.socketFactory.fallback", "false");
  props.setProperty("mail.pop3.socketFactory.port",String.valueOf(port));

  Session session = Session.getInstance(props, null);

  Store store = null;
  store = session.getStore(protocol); // protocol is e.g. "pop3" or "imap"

  store.connect(host, port, user, password);