使用 javamail 解析 eml 无法正确识别嵌套的邮件
The parsing of an eml with javamail doesn't recognize properly nested messages
我正在使用 Javamail 1.5.6 实现 .eml 解析器，我已经开始从 msghow.java 复制 javamail 中提供的示例。
我正在测试一个包含另一个 eml 作为附件的 eml，这是一个摘录：
MIME-Version: 1.0
Date: Tue, 30 Apr 2019 16:20:45 +0200
Message-ID: <CA+fLqEW8TUfSxih9DTp2WXa63pS7wf1eZiro_9k1XS4AShN5Zg@mail.gmail.com>
Subject: Message with an eml as attachment
From: a b <ab@gmail.com>
To: cd@pec.cd.it
Content-Type: multipart/mixed; boundary="00000000000057f76c0587c01bc9"
--00000000000057f76c0587c01bc9
Content-Type: multipart/alternative; boundary="00000000000057f7670587c01bc7"
--00000000000057f7670587c01bc7
Content-Type: text/plain; charset="UTF-8"
Hello guys,
this is a simple message from a not certified account, it contains only one
attachment, an eml message
--00000000000057f7670587c01bc7
Content-Type: text/html; charset="UTF-8"
<div dir="ltr">Hello guys,<div><br></div><div>this is a simple message from a not certified account, it contains only one attachment, an eml message</div></div>
--00000000000057f76c0587c01bc9
Content-Type: message/rfc822; name="Cena zerebao.eml"
Content-Disposition: attachment; filename="Cena zerebao.eml"
Content-Transfer-Encoding: base64
X-Attachment-Id: f_jv3vpu760
Content-ID: <f_jv3vpu760>
WC1Ob3Rlcy1JdGVtOiBGcmksIDYgSnVsIDIwMTggMTc6NDA6MDAgKzAyMDA7DQogdHlwZT00MDA7
IG5hbWU9T3JpZ2luYWxNb2RUaW1lDQpYLU5vdGVzLUl0ZW06IE1lbW87DQogbmFtZT1Gb3JtDQpY
LU5vdGVzLUl0ZW06IFN0ZE5vdGVzTHRyMjU7DQo.... and so on
Javamail 可以识别 eml，但是当我得到它的主题、日期、正文、附件等时，它们都是空的。
msghow.java 本身看不到它们。
在 javamail 之前，我用 mime4j 实现了我的解析器，我没有这个问题，但现在我想尽可能只使用 javamail 来解析 emls
来自描述 mail.mime.allowencodedmessages 属性 的 javadocs:
The MIME spec does not allow body parts of type message/* to be encoded. The Content-Transfer-Encoding header is ignored in this case. Some versions of Microsoft Outlook will incorrectly encode message attachments. Setting this System property to "true" will cause the Content-Transfer-Encoding header to be honored for message attachments. The default value of this property is false.
我正在使用 Javamail 1.5.6 实现 .eml 解析器，我已经开始从 msghow.java 复制 javamail 中提供的示例。
我正在测试一个包含另一个 eml 作为附件的 eml，这是一个摘录：
MIME-Version: 1.0
Date: Tue, 30 Apr 2019 16:20:45 +0200
Message-ID: <CA+fLqEW8TUfSxih9DTp2WXa63pS7wf1eZiro_9k1XS4AShN5Zg@mail.gmail.com>
Subject: Message with an eml as attachment
From: a b <ab@gmail.com>
To: cd@pec.cd.it
Content-Type: multipart/mixed; boundary="00000000000057f76c0587c01bc9"
--00000000000057f76c0587c01bc9
Content-Type: multipart/alternative; boundary="00000000000057f7670587c01bc7"
--00000000000057f7670587c01bc7
Content-Type: text/plain; charset="UTF-8"
Hello guys,
this is a simple message from a not certified account, it contains only one
attachment, an eml message
--00000000000057f7670587c01bc7
Content-Type: text/html; charset="UTF-8"
<div dir="ltr">Hello guys,<div><br></div><div>this is a simple message from a not certified account, it contains only one attachment, an eml message</div></div>
--00000000000057f76c0587c01bc9
Content-Type: message/rfc822; name="Cena zerebao.eml"
Content-Disposition: attachment; filename="Cena zerebao.eml"
Content-Transfer-Encoding: base64
X-Attachment-Id: f_jv3vpu760
Content-ID: <f_jv3vpu760>
WC1Ob3Rlcy1JdGVtOiBGcmksIDYgSnVsIDIwMTggMTc6NDA6MDAgKzAyMDA7DQogdHlwZT00MDA7
IG5hbWU9T3JpZ2luYWxNb2RUaW1lDQpYLU5vdGVzLUl0ZW06IE1lbW87DQogbmFtZT1Gb3JtDQpY
LU5vdGVzLUl0ZW06IFN0ZE5vdGVzTHRyMjU7DQo.... and so on
Javamail 可以识别 eml，但是当我得到它的主题、日期、正文、附件等时，它们都是空的。 msghow.java 本身看不到它们。
在 javamail 之前，我用 mime4j 实现了我的解析器，我没有这个问题，但现在我想尽可能只使用 javamail 来解析 emls
来自描述 mail.mime.allowencodedmessages 属性 的 javadocs:
The MIME spec does not allow body parts of type message/* to be encoded. The Content-Transfer-Encoding header is ignored in this case. Some versions of Microsoft Outlook will incorrectly encode message attachments. Setting this System property to "true" will cause the Content-Transfer-Encoding header to be honored for message attachments. The default value of this property is false.