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Andy Brunner
Andy Brunner

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UnsupportedDataTypeException: Migrating from javax.mail to jakarta.mail

While migrating a simple SMTP mailer class from javax.mail to the current jakarta.mail, I ended up with the error

UnsupportedDataTypeException: no object DCH for MIME type ...

In various forums, some people suggested to write a custom DataHandler to support the missing MIME types in the newer Jakarta mail implementations.

Fortunately, the Java code does not need to be changed (despite the import changes).

After countless number of hours searching the Internet, I finally found the correct jar files to be used during runtime:

  • angus-activation-2.0.2.jar
  • angus-mail-2.0.3.jar
  • jakarta.activation-api-2.1.3.jar
  • jakarta.mail-api-2.1.3.jar

Hope this helps someone else.

Top comments (0)

Great read:

Is it Time to go Back to the Monolith?

History repeats itself. Everything old is new again and I’ve been around long enough to see ideas discarded, rediscovered and return triumphantly to overtake the fad. In recent years SQL has made a tremendous comeback from the dead. We love relational databases all over again. I think the Monolith will have its space odyssey moment again. Microservices and serverless are trends pushed by the cloud vendors, designed to sell us more cloud computing resources.

Microservices make very little sense financially for most use cases. Yes, they can ramp down. But when they scale up, they pay the costs in dividends. The increased observability costs alone line the pockets of the “big cloud” vendors.