Brianegge at 01:37, 4 June 2007

2007-06-04T01:37:10Z

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What could be simplier than sending an email from a command line app in Java? Well, a lot of things. I have an app which works fine in the IDE but fails via the command line with this exception:

<pre>
javax.mail.MessagingException: IOException while sending message;
nested exception is:
javax.activation.UnsupportedDataTypeException: no object DCH for MIME type text/plain; charset=us-ascii
at com.sun.mail.smtp.SMTPTransport.sendMessage(SMTPTransport.java:625)
at javax.mail.Transport.send0(Transport.java:169)
at javax.mail.Transport.send(Transport.java:98)
</pre>

A quick Google search indicates that this is fairly common. In my case, the command line app runs via [[http://one-jar.sourceforge.net/ OneJar]], though most people have their fun when deploying to their app server. The first thing I tried was downloading '''activation.jar'''. I noticed in the IDE I have four different versions of the '''UnsupportedDataTypeException''' class. One comes from log4j, two from weblogic, and one from Jetty. I hoped adding a fifth via activation.jar would solve things. Well, no such luck.

Fortunately, I found one person's solution on [[http://www.jguru.com/faq/view.jsp?EID=237257 JGuru]]. Austin Prichard-Levy suggests adding this to your mail script:

<pre>
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);
</pre>

I did that, and my app started sending mail. I don't know how or why.

JavaMailFun - Revision history

Brianegge at 01:37, 4 June 2007