java - 如何使用 JavaMail API 读取电子邮件附件(当 contentType 为 text/plain 时)

Question

我们有一个外部应用程序，它向我们发送一封带有附件的电子邮件。在 contentType Multipart 的情况下:我们能够解析和处理附件。

但有时他们会发送内容类型为 text/plain 的邮件(message.getContent() 为 null)，我们无法从邮件对象中获取附件和电子邮件正文。

发送方无法将内容类型固定为多部分，我们必须在接收端容纳它。

我们正在使用 JavaMail API 1.5，尝试了 apache commons mail util，但它仅在 message.getContent() 中有对象时才有效

文件夹 emailFolder = store.getFolder("INBOX");emailFolder.open(Folder.READ_ONLY);

消息[] 消息 = emailFolder.getMessages();System.out.println("总消息"+ messages.length);

for (int i = 0; i < messages.length; i++) { 消息message = messages[i];

Multipart multipart = (Multipart) message.getContent();
 for(int k = 0; k < multipart.getCount(); k++){
   BodyPart bodyPart = multipart.getBodyPart(k);  
   InputStream stream = 
                     (InputStream) bodyPart.getInputStream();  
 }

**RAW MIME message content :**
  From: SENDER <SENDER@MyOrgLtd.com>
To: "'support@XYZ.com'" <'support@XYZ.com'>
Subject: Change Request #CHG85 02 ATTACHMENT
Thread-Topic: Change Request #CHG85 02 ATTACHMENT
Thread-Index: AdVQ+bdv3Fd+yaP6Qr2RCdQvPsvI9Q==
Date: Mon, 12 Aug 2019 10:37:23 +0000
Message-ID: <1dcdc97a916b4f929414d0d4b6703397@DELHIXCHMBX003.MyOrgLtd.com>
Accept-Language: en-US
Content-Language: en-US
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--_002_1dcdc97a916b4f929414d0d4b6703397DELHIXCHMBX003MyOrgLtd_
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable

hi User,
    We have received the data, will process and inform you.

Thank you,
admin


--_002_1dcdc97a916b4f929414d0d4b6703397DELHIXCHMBX003MyOrgLtd_
Content-Type: application/octet-stream; name="testData.csv"
Content-Description: testData.csv
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    creation-date="Mon, 12 Aug 2019 10:35:38 GMT";
    modification-date="Mon, 12 Aug 2019 10:35:38 GMT"
Content-Transfer-Encoding: base64

IkNpcmN1aXQgIiwiU2V2ZXJpdHkiCiJDaXJjdWl0OSAgICAvU0EgIC8iLCJPdXRhZ2UiCiJDaXJjdWl0MTQgICAgL1NMICAvIiwiT3V0YWdlIgoiQ2lyY3VpdDggICAgL1NCICAvIiwiT3V0YWdlIgoiQ2lyY3VpdDUgICAgL1NCICAvIiwiT3V0YWdlIgoiQ2lyY3VpdDYgICAgL1NUICAvIiwiT3V0YWdlIgoiQ2lyY3VpdDcgICAgL1NCICAvIiwiT3V0YWdlIgoiQ2lyY3VpdDIgICAgL1NHICAvIiwiT3V0YWdlIgoiQ2lyY3VpdDUxICAgIC9TQiAgLyIsIk91dGFnZSIKIkNpcmN1aXQxICAgIC9TTSAgLyIsIk91dGFnZSIKIkNpcmN1aXQ0ICAgIC9TQiAgLyIsIk91dGFnZSI=

--_002_1dcdc97a916b4f929414d0d4b6703397DELHIXCHMBX003MyOrgLtd_--

Answer 1

如果内容类型是text/plain，则没有附件。

如果 message.getContent() 返回 null，则可能也没有消息内容，或者消息的格式有问题。发布消息的原始 MIME 内容，我可以帮助您找出消息的问题。