The more the geronimo javamail support is starting to get used, the more
uncomfortable I'm getting with the current structure of the javamail
code. Let me level-set the situation first, so everybody understands
the issues.
To start with, the Sun impl of javamail is not really like other jar
files we consider "spec" code. This jar files contains lots of classes
in the javax.mail.* package tree, but it also contains a number of
backing classes in a com.sun.mail.* tree that help implement certain
features. For example, there are various encoders/decoders used by the
MimeUtility class. These classes are undocumented, and are separate
from the public javamail api classes.
In addition to those classes, the Sun javamail jar file contains the Sun
implementations of the protocol transports and stores (smtp, pop3, and
imap are supported). In order to use the Sun version of javamail, you
only need to javamail jar and the jaf (activation jar).
For the Geronimo implementation, things are split up a little more. The
geronimo-spec-javamail jar file contains all of the javax.mail.*
classes, plus whatever backing utility classes are needed to implement
some of the features (with org.apache.geronimo.* package structure).
The jar does NOT however, contain any of the protocol implementations.
The Geronimo protocol implementations are contained in the
javamail-transport module of the main Geronimo code tree. This jar
contains only the protocol implementations, plus some utility classes
shared between the protocols. In order to use the Geronimo javamail
support, you need 3 jar files: 1) the activation jar, 2) the javamail
jar, and 3) the javamail-transport jar. 1) and 2) are available
separately, but 3) IIUC, is only available within a Geronimo snapshot jar.
And just to confuse matters even more, there is another Geronimo mail
module. This module contains GBeans for configuring various mail
resources. These GBeans are independent of which javamail
implementation is being used, so we can keep these out of the discussion.
There is a major problem with the current Geronimo structure. The
implementation of the protocol handlers (transports and stores) is
highly dependent on the version of the api they are written to. I ran
into this problem just today. Jira GERONIMO-1957 addressed the fact that
changes in the geronimo 1.1 javamail spec jar broke the 1.0 version of
the SMTP transport. However, the current 1.1 codebase was running with
this obsolete code, so I had to back port the trunk version of the SMTP
transport into the 1.1 code tree. This also raised the question of
whether we should pull back the other transport/store implementations
into 1.1.
Now this is an issue that never arises with the Sun implementation.
Since the protocol handlers are contained within the API jar, you can
never get these packages out of sync. They travel around together by
definition. In order for somebody to make use of the Geronimo javamail
stack, you'd need to pull down the javamail and activation spec jars,
then extract a javamail-transport jar from a Geronimo snapshot that was
using a matching spec level. Lots of opportunity for error here, and it
makes it difficult for other projects to use the javamail support. Axis
is already doing this, but fortunately, they are only using the
javax.mail.* stuff for Mime encoding support and are not dependent on
transport or store implementations.
It seems, at a minimum, that the javamail-transport code should be moved
from being a Geronimo module to a spec component. Ideally, it really
should be merged into the javamail spec module to mirror how the Sun
implementation works.
Am I missing something? Is there some compelling reason why this should
be structured this way? I really suspect we ended up at this point
through a combination of ignorance and historical accident. Originally,
the smtp transport code was just a sandbox component. It was upgraded
into working code because the console wanted to implement a portlet for
configuring mail resouces configurations. When this code was promoted
out of the sandbox, a new javamail-transport module was created because
we weren't really sure where it really belonged....and we named it badly
to boot. It really should have been called javamail-protocol. The
transport portion of the name starting looking silly when we add the
pop3 STORE protocol handler.
Rick
- Should javamail be reorganized? Rick McGuire
-
