JavaMail Problem with JRE 6.0 using JNI

Thanks, I tried that with the following results... I can't fingure out why it can't find the content handler class - it's in the mail.jar which is on the classpath in the package specified. This is also only a problem when invoked from JNI, so I don't know if that has anything to do with how the classes are loaded?

MailcapCommandMap: createDataContentHandler for multipart/mixed

search DB #1

search DB #2

got content-handler

class com.sun.mail.handlers.multipart_mixed

Can't load DCH com.sun.mail.handlers.multipart_mixed; Exception: java.lang.ClassNotFoundException: com/sun/mail/handlers/multipart_mixed

search DB #3

search fallback DB #1

got content-handler

class com.sun.mail.handlers.multipart_mixed

Can't load DCH com.sun.mail.handlers.multipart_mixed; Exception: java.lang.ClassNotFoundException: com/sun/mail/handlers/multipart_mixed

search fallback DB #2

search fallback DB #3

Devoa at 2007-7-12 10:11:00 >

I've added that line of code and it instantiates the object correctly, but the original error still persists. I've printed out the file location to check where it was loading it from, and it was the same mail.jar that the mailcap file is in.

Object o = new com.sun.mail.handlers.multipart_mixed();

URL location = o.getClass().getProtectionDomain().getCodeSource().getLocation();

System.out.println(o.getClass().getName() + ".getProtectionDomain().getCodeSource().getLocation():" + location.toString());

I've checked the classpath again and couldn't find any duplicates. The classpath is pretty simple (I printed it out using System.getProperty("java.class.path") to check) and aside from two custom jars containing packages specific to the app, the only external ones are: jaxb-libs.jar, jaxb-ri.jar, Junit.jar, log4j-1.2.7.jar, mail.jar, namespace.jar

Devoa at 2007-7-12 10:11:00 >

The contents of my jre/lib/ext is: dnsns.jar, localedata.jar, sunjce_provider.jar, sunmscapi.jar, sunpkcs11.jar

Yep, our app works using JNI under 1.4.2 and 1.5, but not 1.6.

I wrote a little stand alone test that contained the line of code that was causing the issue and ran it under 1.6 (from the command prompt) and it worked fine. I'll post this on the JNI forum and see if anyone knows why the class can't be found.

In the meantime i'll also try to put together a simple test case using JNI.

Thanks.

Devoa at 2007-7-12 10:11:00 >

JAF 1.1

JavaMail 1.4

JRE 1.6.0_01

JDK 1.4.2_13

IMAP ser ver: Exchange 2003

The following jars in the applet class path: signed.jar, mailapi.jar, activation.jar, httpclient.jar, logging.jar, codec.jar, lang.jar, bsh.jar, imap.jar, pop3.jar, smtp.jar

We can open and read mail from the server just fine. We CAN'T open/save attachments. We get the following error:

Exception in thread "Thread-9" java.lang.ClassCastException: com.sun.mail.imap.IMAPInputStream cannot be cast to javax.mail.Multipart

Which is caused by this piece of code:

Multipart mp = (Multipart) m.getContent();

Setting the system property -Djavax.activation.debug=true allows me to see this error infromation:

MailcapCommandMap: createDataContentHandler for multipart/mixed

search DB #1

search DB #2

search fallback DB #1

got content-handler

class com.sun.mail.handlers.multipart_mixed

Can't load DCH com.sun.mail.handlers.multipart_mixed; Exception: java.lang.ClassNotFoundException: com/sun/mail/handlers/multipart_mixed

search fallback DB #2

The mailcap file in the mailapi.jar looks like this:

#

# @(#)mailcap1.8 05/04/20

#

# Default mailcap file for the JavaMail System.

#

# JavaMail content-handlers:

#

text/plain;;x-java-content-handler=com.sun.mail.handlers.text_plain

text/html;;x-java-content-handler=com.sun.mail.handlers.text_html

text/xml;;x-java-content-handler=com.sun.mail.handlers.text_xml

multipart/*;;x-java-content-handler=com.sun.mail.handlers.multipart_mixed; x-java-fallback-entry=true

message/rfc822;;x-java-content-handler=com.sun.mail.handlers.message_rfc822

#

# can't support image types because java.awt.Toolkit doesn't work on servers

#

#image/gif;;x-java-content-handler=com.sun.mail.handlers.image_gif

#image/jpeg;;x-java-content-handler=com.sun.mail.handlers.image_jpeg

I tried putting it outside or the jar in the META-INF directory of the applet codebase, no change, still get the error.

I can put the following code in and load the class that is claims it can't find:

Object o = new com.sun.mail.handlers.multipart_mixed();

URL location = o.getClass().getProtectionDomain().getCodeSource().getLocation();

System.out.println("\n"+o.getClass().getName() + ".getProtectionDomain().getCodeSource().getLocation():" + location.toString());

That prints:

com.sun.mail.handlers.multipart_mixed.getProtectionDomain().getCodeSource().getLocation():http://localhost:2696/MM_Web/jars/mailapi.jar

Which is clearly loading the class from the right place. What the heck is going on? This stuff works perfectly in 1.4 and 1.5.

I also tried removing the activation jar from the applet tag just in case the activation classes included in the 1.6 rt.jar where conflicting. No luck here either.

I also tried putting this in the code:

MailcapCommandMap mc = (MailcapCommandMap)CommandMap.getDefaultCommandMap();

mc.addMailcap("text/html;; x-java-content-handler=com.sun.mail.handlers.text_html");

mc.addMailcap("text/xml;; x-java-content-handler=com.sun.mail.handlers.text_xml");

mc.addMailcap("text/plain;; x-java-content-handler=com.sun.mail.handlers.text_plain");

mc.addMailcap("multipart/*;; x-java-content-handler=com.sun.mail.handlers.multipart_mixed");

mc.addMailcap("message/rfc822;; x-java-content-handler=com.sun.mail.handlers.message_rfc822");

CommandMap.setDefaultCommandMap(mc);

No go still broken.

The mailcap.default file in the 1.6 resources.jar file looks like this:

#

# This is a very simple 'mailcap' file

#

image/gif;;x-java-view=com.sun.activation.viewers.ImageViewer

image/jpeg;;x-java-view=com.sun.activation.viewers.ImageViewer

text/*;;x-java-view=com.sun.activation.viewers.TextViewer

text/*;;x-java-edit=com.sun.activation.viewers.TextEditor

Also tried JavaMail 1.4.1ea from the glssfish project, still broken.

Message was edited by:

zparticle

zparticlea at 2007-7-12 10:11:00 >

Okay I tried putting the mail jar in the ext dir of the JRE and it still blows up with the same error. This code works perfectly in 1.4 and 1.5. The applet is signed and I have full access to the machine so I don't know what the problem is.

This is very frustrating, LOL. Any other ideas?

I also tried switching over to the single mail jar with all of the providers included, still no go. If this is really a problem with a class loader why does this work?

Object o = new com.sun.mail.handlers.multipart_mixed();

One other thing, it seems to work when we run the junits which hit the underlying classes without going through the applet.

According to the javadocs: "The object returned for a "multipart" content is always a Multipart subclass"

The interesting part is if I detect that the method returned an InputStream I can read the contents of the stream and it is the enitre mime message. Does that help?

Message was edited by:

zparticle

zparticlea at 2007-7-12 10:11:00 >

Thanks very much for your help.

I tried the context class loader using:

Thread t = Thread.currentThread();

ClassLoader cl = t.getContextClassLoader();

cl.loadClass("com.sun.mail.handlers.multipart_mixed");

The ClassLoader comes back as null, do I need to do something here? I'm sure I don't unserstand the purpose.

I also put in the -Djavax.activation.debug=true and no extra messages were dumped to the console so I assume that means I'm doing the security thing correctly. The download attachment thread is started inside of a

AccessController.doPrivileged(new PrivilegedExceptionAction() {

block which should be giving me all the privs I need.

If you have no other ideas I can try to create something to reproduce this but there is a large amount of code involved.

==================================

Thought I'd throw this in here to be complete. This is the debug output when I originally read the message before I go to download the attachment.

MailcapCommandMap: load HOME

new MailcapFile: file C:\Documents and Settings\sshaver\.mailcap

MailcapCommandMap: load SYS

new MailcapFile: file C:\PROGRA~1\Java\JRE16~1.0_0\lib\mailcap

MailcapCommandMap: load JAR

MailcapCommandMap: getResources

MailcapCommandMap: URL jar:http://localhost:2696/MM_Web/jars/mail.jar!/META-INF/mailcap

new MailcapFile: InputStream

parse: text/plain;;x-java-content-handler=com.sun.mail.handlers.text_plain

Type: text/plain

Command: content-handler, Class: com.sun.mail.handlers.text_plain

parse: text/html;;x-java-content-handler=com.sun.mail.handlers.text_html

Type: text/html

Command: content-handler, Class: com.sun.mail.handlers.text_html

parse: text/xml;;x-java-content-handler=com.sun.mail.handlers.text_xml

Type: text/xml

Command: content-handler, Class: com.sun.mail.handlers.text_xml

parse: multipart/*;;x-java-content-handler=com.sun.mail.handlers.multipart_mixed; x-java-fallback-entry=true

Type: multipart/*

Command: content-handler, Class: com.sun.mail.handlers.multipart_mixed

parse: message/rfc822;;x-java-content-handler=com.sun.mail.handlers.message_rfc822

Type: message/rfc822

Command: content-handler, Class: com.sun.mail.handlers.message_rfc822

MailcapCommandMap: successfully loaded mailcap file from URL: jar:http://localhost:2696/MM_Web/jars/mail.jar!/META-INF/mailcap

MailcapCommandMap: load DEF

new MailcapFile: InputStream

parse: image/gif;;x-java-view=com.sun.activation.viewers.ImageViewer

Type: image/gif

Command: view, Class: com.sun.activation.viewers.ImageViewer

parse: image/jpeg;;x-java-view=com.sun.activation.viewers.ImageViewer

Type: image/jpeg

Command: view, Class: com.sun.activation.viewers.ImageViewer

parse: text/*;;x-java-view=com.sun.activation.viewers.TextViewer

Type: text/*

Command: view, Class: com.sun.activation.viewers.TextViewer

parse: text/*;;x-java-edit=com.sun.activation.viewers.TextEditor

Type: text/*

Command: edit, Class: com.sun.activation.viewers.TextEditor

Merging commands for type text/*

MailcapCommandMap: successfully loaded mailcap file: /META-INF/mailcap.default

MailcapCommandMap: createDataContentHandler for multipart/mixed

search DB #1

search DB #2

search fallback DB #1

got content-handler

class com.sun.mail.handlers.multipart_mixed

MailcapCommandMap: createDataContentHandler for multipart/alternative

search DB #1

search DB #2

search fallback DB #1

got content-handler

class com.sun.mail.handlers.multipart_mixed

MailcapCommandMap: createDataContentHandler for text/plain

search DB #1

got content-handler

class com.sun.mail.handlers.text_plain

MailcapCommandMap: createDataContentHandler for text/html

search DB #1

got content-handler

class com.sun.mail.handlers.text_html

MailcapCommandMap: createDataContentHandler for application/msword

search DB #1

search DB #2

search fallback DB #1

search fallback DB #2

Message was edited by:

zparticle

I also added the:

-Djava.security.debug="access,failure,jar"

and got a ton of output the all looked something like this:

access: access allowed (java.security.AllPermission <all permissions> <all actions>)

access: access allowed (java.lang.RuntimePermission createClassLoader)

They always say "access allowed" there were no errors.

Message was edited by:

zparticle

zparticlea at 2007-7-12 10:11:00 >

Yeah I just removed 1.6 and ran against 1.5 again. The ClassLoader comes back null there as well but the code runs perfectly and downloads the attachment.

Any ideas on how I can work around this 1.6 issue. We are getting close to having our product go to "Open Beta" status and this is really going to hurt us. Can I set the class loader myself somehow?

Message was edited by:

zparticle

zparticlea at 2007-7-12 10:11:00 >

Okay that seemd to work, I'll have to test everything again with the old JREs to make sure this doesn't hose something else up though. Anyway thank you very much. So this is a bug in 1.6 right?

I added the following code to the top of the run method of the download thread:

setContextClassLoader(CCApplet1.getBaseClassLoader());

and this to the main applet class:

static public final ClassLoader getBaseClassLoader(){

try{

return Class.forName("com.cc.applet.CCApplet1").getClassLoader();

}catch(Exception x){

return null;

}

}

zparticlea at 2007-7-21 21:15:59 >

Hi Guys,

Glad(?) to hear someone else is having a similar problem to the one I'm still having.

bshannon - I haven't posted up a sample app yet as the stand alone app I wrote works ok, but I can't figure out what the difference is (aside from complexity (of both the JNI and the Java), size and the use of reflection in the non-working version). Also, if this is a bug in the JRE, I don't think it is limited to applet support as I'm not using applets but am getting the same error. It does appear to me to be classloader related, so any advice is appreciated!

Devoa at 2007-7-21 21:15:59 >

"the stand alone app I wrote works ok"

Devo - Based on that I would say your are having the same problem I was with the context class loader not being set because our juints ran just fine. This is because they use a completely different method of class loading than the applet we have does.

Good luck with your project, this was extreemly frustrating.

zparticlea at 2007-7-21 21:15:59 >

I checked with the JRE team and they assure me that the applet container

has always set the context class loader. And indeed a simple test applet

shows that it's set and that JAF is able to load the DataContentHandlers

from mail.jar.

Do you have a simple test applet that shows the problem?

Are you sure nothing else in your application is setting the context class loader?

bshannona at 2007-7-21 21:15:59 >

And yet, in my trivial test program, it clearly is being set.

There's something else about your environment that's causing the

problem and we're going to need to do some debugging in your environment

to figure it out.

Here's my simple test program. Try this in your environment.

import java.awt.*;

import java.applet.*;

import java.io.*;

import javax.activation.*;

import javax.mail.util.*;

public class ccltest extends Applet {

public void init() {

String text = "NONE";

try {

ClassLoader cl = Thread.currentThread().getContextClassLoader();

text = cl.toString();

} catch (SecurityException sex) {

text = sex.toString();

}

add(new TextField(text));

String s = null;

try {

DataHandler dh = new DataHandler(

new ByteArrayDataSource("test data", "text/plain"));

s = (String)dh.getContent();

} catch (IOException ex) {

s = ex.toString();

}

add(new TextField(s));

}

}

Reference it using:

<applet code=ccltest.class width="400" archive="mail.jar">

bshannona at 2007-7-21 21:16:04 >