ClassCastException when sending email (JDK 11)

• Type: Bug
• Status: Closed
• Resolution: Fixed
• Affects Version/s: Master
• Fix Version/s: 7.1.10 DXP FP4, 7.1.10.1 SP1, 7.1.2 CE GA3, 7.1.X, Master
• Component/s: Core Infrastructure, Environments > Java Runtime
• Labels:
  • jdk11
  • liferay-dxp-71-sp1
  • liferay-fixpack-dxp-4-7110
• Branch Version/s:
  7.1.x
• Backported to Branch:
  Committed
• Fix Priority: 5
• JDK:
  Oracle OpenJDK 11
• Git Pull Request: https://github.com/brianchandotcom/liferay-portal/pull/65470

Steps to reproduce:

1. Compile portal on JDK8
   • as of writing this ticket, aries workaround needs to be applied before building (https://github.com/brianchandotcom/liferay-portal/pull/64744)
2. Start portal on JDK11
3. Login
4. Go to Message Boards
5. Add a new thread
6. Publish (to trigger email)

Also reproduced using Workflow, or creating a new user account.

Expected Result:
Email is sent, no errors are thrown.

Actual Result:
No email is sent due to ClassCastException

ERROR [liferay/mail-1][ParallelDestination:55] Unable to process message {destinationName=liferay/mail, response=null, responseDestinationName=null, responseId=null, [email protected], values={defaultLocale=en_US, companyId=20099, groupId=0, principalName=20139, [email protected]4c6aa89f, siteDefaultLocale=en_US, themeDisplayLocale=en_US}}
com.liferay.portal.kernel.messaging.MessageListenerException: com.liferay.petra.mail.MailEngineException: java.lang.ClassCastException: class com.sun.mail.handlers.text_html cannot be cast to class javax.activation.DataContentHandler (com.sun.mail.handlers.text_html is in unnamed module of loader org.apache.catalina.loader.ParallelWebappClassLoader @5b43fbf6; javax.activation.DataContentHandler is in unnamed module of loader java.net.URLClassLoader @4e9ba398)
	at com.liferay.portal.kernel.messaging.BaseMessageListener.receive(BaseMessageListener.java:32)
	at com.liferay.portal.kernel.messaging.InvokerMessageListener.receive(InvokerMessageListener.java:74)
	at com.liferay.portal.kernel.messaging.ParallelDestination$1.run(ParallelDestination.java:52)
	at com.liferay.portal.kernel.concurrent.ThreadPoolExecutor$WorkerTask._runTask(ThreadPoolExecutor.java:752)
	at com.liferay.portal.kernel.concurrent.ThreadPoolExecutor$WorkerTask.run(ThreadPoolExecutor.java:664)
	at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: com.liferay.petra.mail.MailEngineException: java.lang.ClassCastException: class com.sun.mail.handlers.text_html cannot be cast to class javax.activation.DataContentHandler (com.sun.mail.handlers.text_html is in unnamed module of loader org.apache.catalina.loader.ParallelWebappClassLoader @5b43fbf6; javax.activation.DataContentHandler is in unnamed module of loader java.net.URLClassLoader @4e9ba398)
	at com.liferay.petra.mail.MailEngine.send(MailEngine.java:396)
	at com.liferay.petra.mail.MailEngine.send(MailEngine.java:461)
	at com.liferay.mail.messaging.MailMessageListener.doMailMessage(MailMessageListener.java:94)
	at com.liferay.mail.messaging.MailMessageListener.doReceive(MailMessageListener.java:109)
	at com.liferay.portal.kernel.messaging.BaseMessageListener.receive(BaseMessageListener.java:26)
	... 5 more
Caused by: java.lang.ClassCastException: class com.sun.mail.handlers.text_html cannot be cast to class javax.activation.DataContentHandler (com.sun.mail.handlers.text_html is in unnamed module of loader org.apache.catalina.loader.ParallelWebappClassLoader @5b43fbf6; javax.activation.DataContentHandler is in unnamed module of loader java.net.URLClassLoader @4e9ba398)
	at javax.activation.MailcapCommandMap.getDataContentHandler(MailcapCommandMap.java:596)
	at javax.activation.MailcapCommandMap.createDataContentHandler(MailcapCommandMap.java:550)
	at javax.activation.DataHandler.getDataContentHandler(DataHandler.java:611)
	at javax.activation.DataHandler.writeTo(DataHandler.java:315)
	at javax.mail.internet.MimeUtility.getEncoding(MimeUtility.java:248)
	at javax.mail.internet.MimeBodyPart.updateHeaders(MimeBodyPart.java:1268)
	at javax.mail.internet.MimeMessage.updateHeaders(MimeMessage.java:2012)
	at javax.mail.internet.MimeMessage.saveChanges(MimeMessage.java:1980)
	at javax.mail.Transport.send(Transport.java:119)
	at com.liferay.petra.mail.MailEngine._send(MailEngine.java:618)
	at com.liferay.petra.mail.MailEngine.send(MailEngine.java:386)
	... 9 more