错误：阅读电子邮件内容时出现 javax.mail.internet.MimeMultipart

Posted 2023-03-15

【中文标题】错误：阅读电子邮件内容时出现 javax.mail.internet.MimeMultipart

【英文标题】：error : javax.mail.internet.MimeMultipart while reading the email content

【发布时间】：2015-08-26 22:19:27

【问题描述】：

我有以下代码来使用 Java 阅读 Gmail 电子邮件。如果电子邮件包含非常简单的纯文本消息，那么代码工作正常，我能够看到（正文）的内容正确显示。

但是，对于某些电子邮件，我在尝试时会看到以下消息

显示正文（内容：javax.mail.internet.MimeMultipart@2038ae61）

。我发现很难解决这个问题。请帮帮我。

代码：

import java.util.Properties;

import javax.activation.DataHandler;
import javax.mail.Address;
import javax.mail.BodyPart;
import javax.mail.Folder;
import javax.mail.Message;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Store;
import javax.mail.internet.MimeMultipart;

public class Experiment 
    public static void main(String[] args) 
        Properties props = new Properties();
        props.setProperty("mail.store.protocol", "imaps");
        try 
            Session session = Session.getInstance(props, null);
            Store store = session.getStore();
            store.connect("imap.gmail.com", "[e-mail]",
                    "password");
            Folder inbox = store.getFolder("INBOX");
            inbox.open(Folder.READ_ONLY);
            Message msg = inbox.getMessage(inbox.getMessageCount());
            Address[] in = msg.getFrom();
            for (Address address : in) 
                System.out.println("FROM:" + address.toString());
            

            // showContent(msg);


            Multipart mp = (Multipart) msg.getContent();
            BodyPart bp = mp.getBodyPart(0);
            System.out.println("SENT DATE:" + msg.getSentDate());
            System.out.println("SUBJECT:" + msg.getSubject());
            System.out.println("CONTENT:" + bp.getContent());


         catch (Exception mex) 
            mex.printStackTrace();
        
    

【问题讨论】：

this 回答可能会提供一些见解

您好，感谢您指出帖子。显然，该帖子指向解释电子邮件发送的帖子。我的问题是在阅读电子邮件内容时。

【参考方案1】：

这对我有用

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

   if (contentType.contains("multipart")) 
        Multipart multiPart = (Multipart) message.getContent();
        int numberOfParts = multiPart.getCount();
        for (int partCount = 0; partCount < numberOfParts; partCount++) 
            MimeBodyPart part = (MimeBodyPart) multiPart.getBodyPart(partCount);
                messageContent = part.getContent().toString();
        
    
    else if (contentType.contains("text/plain")
            || contentType.contains("text/html")) 
        Object content = message.getContent();
        if (content != null) 
            messageContent = content.toString();
        
    
     System.out.println(" Message: " + messageContent);

【参考方案2】：

这是一个完整的文件附件阅读解决方案：

    final Map<String, byte[]> attachments = new HashMap<>();
    try 
        if ( mailMessage.getContentType().contains("multipart") && mailMessage.getContent() instanceof Multipart ) 
            final Multipart multiPart = (Multipart) mailMessage.getContent();
            for ( int i = 0; i < multiPart.getCount(); i++ ) 
                final MimeBodyPart part = (MimeBodyPart) multiPart.getBodyPart(i);
                if ( Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition()) ) 
                    final String fileName = MimeUtility.decodeText(part.getFileName());                        
                    final byte[] bytes = IOUtils.toByteArray(part.getInputStream());
                    attachments.put(fileName, bytes);                    
            
        
     catch (final IOException | javax.mail.MessagingException e) 
        throw new IllegalStateException(e);
    
    attachments.forEach(( f, c ) -> 
        System.out.println("filename: " + f + " content:" + new String(c));
    );