java.lang.ClassCastException：java.lang.String不能转换为javax.mail.Multipart

本文介绍了java.lang.ClassCastException：java.lang.String不能转换为javax.mail.Multipart的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

这是我从java教程中获取的代码，但是当我尝试接收从计算机发送的正常消息，而不是通过GMail发送时，我的问题出现了。如果我通过GMail收到电子邮件，它运行正常并返回邮件，但是尝试从常规桌面邮件客户端检索邮件返回

This is my code below taken from a java tutorial - however my issue comes in when I try and recieve a normal message sent from a computer, as opposed to sent through GMail. If I recieve the email through GMail it runs fine and returns the mail, however trying to retrieve a mail from a conventional desktop mail client returns

错误：

java.lang.ClassCastException: java.lang.String cannot be cast to javax.mail.Multipart at gridnotifierproject_pcbuild.HandleMailInput.retrieveOneMail(HandleMailInput.java:37) at gridnotifierproject_pcbuild.GridNotifierProject_PCBuild.main(GridNotifierProject_PCBuild.java:22)

代码：

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", "***********@gmail", "******"); System.out.println("Established Connection to Server!"); Folder inbox = store.getFolder("Inbox"); inbox.open(Folder.READ_ONLY); Message msg = inbox.getMessage(inbox.getMessageCount()); System.out.println("Found specified Folder, retrieving the latest message..."); Address[] in = msg.getFrom(); for (Address address : in) { System.out.println("FROM:" + address.toString()); } 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(); }

推荐答案

！

您的消息内容返回String，您正在尝试键入转换为Multipart。

Your message content returning String and you are trying to type cast to Multipart.

Object content = msg.getContent(); if (content instanceof String) { String body = (String)content; ... } else if (content instanceof Multipart) { Multipart mp = (Multipart)content; ... }