警告: Unable to find required classes (javax.activation.DataHandler and javax .mail.internet.MimeMultip-CSDN博客
NoClassDefFoundError: javax/mail/Transportwhile exception sending email using javax.mail (Java in General forum at Coderanch)
![Enhancement: Clarify dependency on Jakarta Activation: DataSources no longer work on Java 9+ · Issue #225 · bbottema/simple-java-mail · GitHub Enhancement: Clarify dependency on Jakarta Activation: DataSources no longer work on Java 9+ · Issue #225 · bbottema/simple-java-mail · GitHub](https://user-images.githubusercontent.com/2115718/65775691-f53bbc00-e140-11e9-9160-8b670407eba0.png)
Enhancement: Clarify dependency on Jakarta Activation: DataSources no longer work on Java 9+ · Issue #225 · bbottema/simple-java-mail · GitHub
javax.activation/src/main/java/javax/activation/DataHandler.java at master · kohsuke/javax.activation · GitHub
![java - How to correctly configure Apache tomcat 9 within eclipse because I have the necessary jar files (mail.jar and activation.jar) - Stack Overflow java - How to correctly configure Apache tomcat 9 within eclipse because I have the necessary jar files (mail.jar and activation.jar) - Stack Overflow](https://i.stack.imgur.com/WpNkE.png)
java - How to correctly configure Apache tomcat 9 within eclipse because I have the necessary jar files (mail.jar and activation.jar) - Stack Overflow
javax.activation not available in JDK 9 [SPR-16115] · Issue #20663 · spring-projects/spring-framework · GitHub
![Exception: java.lang.ClassNotFoundException: javax.activation.DataHandler even though javax.mail.jar is under classpath? - Stack Overflow Exception: java.lang.ClassNotFoundException: javax.activation.DataHandler even though javax.mail.jar is under classpath? - Stack Overflow](https://i.stack.imgur.com/iqZYJ.png)