Mime Message could not be parsed

I have following mime message:

Date: Mon, 3 Aug 2015 12:42:23 +0000 (UTC)
From: test@test.com
To: test@test.com
Message-ID: <385098705.398991.1438605743348.JavaMail.sd@sdapp04>
Subject: Update
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit



|0004625641|
|630805367|
|NA14220388|
|03.08.2015 14:42:23|


||

I want to parse the message in grails with this code:

InputStream mailFileInputStream = new FileInputStream("/home/peter/test.msg");
    Properties props = new Properties();
    Session session = Session.getDefaultInstance(props, null);
    MimeMessage message = new MimeMessage(session, mailFileInputStream);

    MimeMessageParser parser = new MimeMessageParser(message)
    parser.parse()


    def data = [:]
    data.from = parser.getFrom()
    data.to = parser.getTo()
    data.replyTo = parser.getReplyTo()
    data.html = parser.getHtmlContent()
    data.plain = parser.getPlainContent()
    data.subject = parser.getSubject()
    data.attachments = parser.getAttachmentList()

But the message is not parsed correctly. The whole message is in the plain content. What is the problem with this message?

Best regards, Peter

Solution

When I tried to parse the message I got this exception:

java.lang.ClassCastException: javax.mail.util.SharedByteArrayInputStream cannot be cast to java.lang.String
    at org.apache.commons.mail.util.MimeMessageParser.parse(MimeMessageParser.java:181)
    at org.apache.commons.mail.util.MimeMessageParser.parse(MimeMessageParser.java:96)
    at org.apache.commons.mail.util.MimeMessageParser$parse.call(Unknown Source)

The problem is that MimeMessageParser is trying to coerce an Object into a String. You can see this in the source code on line 181. The object is an instance of javax.mail.util.SharedByteArrayInputStream, and it's not going to return the contents through coercion. My example uses a StringBufferInputStream as the input, so that may play a part in the problem.

Work-around

To work around this issue, I overrode MimeMessage.getContent() so it returns the plain-text content. So obviously, don't do this with non-plain-text content. Here's the complete script:

@Grab('org.apache.commons:commons-email:1.4')

import javax.mail.Session
import javax.mail.internet.MimeMessage
import org.apache.commons.mail.util.MimeMessageParser

def input = '''Return-Path: <some@adress.com>
X-Original-To: some@adress.com
Delivered-To: some@adress.com
Received: from localhost [127.0.0.1]
    by unify-prod with POP3 (fetchmail-6.3.21)
    for <other@localhost> (single-drop); Mon, 03 Aug 2015 12:42:24+0000 (UTC)
Received: from testdomain.com (testdomain.com [192.69.176.183])
    by unify.test.com (Postfix) with ESMTPS id AA3874330B
    for <test@test.com>; Mon,  3 Aug 2015 12:42:23 +0000 (UTC)
 Received: from test.call (test.call [10.3.1.49])
    by test.com (Postfix) with ESMTP id 56EC73BA8C4
    for <test@test.com>; Mon,  3 Aug 2015 12:42:23 +0000 (UTC)
Date: Mon, 3 Aug 2015 12:42:23 +0000 (UTC)
From: test@test.com
To: test@test.com
Message-ID: <385098705.398991.1438605743348.JavaMail.sd@sdapp04>
Subject: Update
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit



|0004625641|
|630805367|
|NA14220388|
|03.08.2015 14:42:23|


||'''

// Creates a MimeMessage that makes MimeMessageParser happy.
MimeMessage createMimeMessage(InputStream stream) {
    def getContent = MimeMessage.metaClass.getMetaMethod('getContent')
    def message = new MimeMessage(
        Session.getDefaultInstance(new Properties()), 
        stream)

    /*
     * Override MimeMessage.getContent()
     * to coerce SharedByteArrayInputStream
     * into a String. Groovy does it automatically :)
     */
    message.metaClass.getContent = {
        getContent.invoke(delegate)
    }

    return message
}

def message = createMimeMessage(new StringBufferInputStream(input))
def parser = new MimeMessageParser(message)

parser.parse()

def data = parser.with {
    [
        from: from,
        to: to,
        replyTo: replyTo,
        html: htmlContent,
        plain: plainContent,
        subject: subject,
        attachments: attachmentList,
    ]
}

assert data.from == 'test@test.com'
assert data.to instanceof List
assert data.replyTo == 'test@test.com'
assert data.html == null
assert data.attachments == []
assert data.plain instanceof String

The data Map contains the following:

[from:test@test.com, to:[test@test.com], replyTo:test@test.com, html:null, plain:

|0004625641|
|630805367|
|NA14220388|
|03.08.2015 14:42:23|


||, subject:Update, attachments:[]]