Hello everyone! I am new to Vaadin and web development in general. I am following ‘Spring Boot Web App Tutorial’ video on
vaadinofficial Youtube channel. I have already downloaded the project from ‘Project Setup’ → ‘Download Starter’. However, once I run the application through Intellij IDEA, I get the error ‘java: pattern matching in instanceof is not supported in -source 13
(use -source 16 or higher to enable pattern matching in instanceof)’, referring to the ‘equals’ method in the ‘AbstractEntity’ class. In project configuration window, my Project SKD is ‘semuru-16’ and project language level is ‘16 (Preview) - Sealed types’. How can I solve this issue? I want to proceed with learning this subject, but can’t overcome this setup issue.
Java 16 is EoL. Use Java 17 and the latest stacks and the problem should be gone
I wonder why your IDEA decides to use Java 13 source version
You should use Java 17 (latest long term support) at least for anything new. Could you try to update your IntelliJ & update to JDK 17.
Thank you guys, updating my IDEA to the latest version solved my issue.