SpringBoot AnsiOutput.detectIfAnsiCapable broken on JDK22

The detectIfAnsiCapable method in AnsiOutput does not work correctly on JDK22. It checks if System.console() returns null, but on JDK22 System.console() never returns null; there's a new method on Console to detect if the instance is a terminal or not.

Some details here about the change:

System.console() now returns a Console object when the standard streams are redirected or connected to a virtual terminal. Prior to JDK 22, System.console() instead returned null for these cases. This change may impact code that checks the return from System.console() to test if the JVM is connected to a terminal. If required, the -Djdk.console=java.base flag will restore the old behavior where the console is only returned when it is connected to a terminal. Starting JDK 22, one could also use the new Console.isTerminal() method to test if the console is connected to a terminal.

The result is that on JDK22, color / ANSI output is turned on when it shouldn't be.

Comment From: facewise

@scottfrederick @kilink Hello. Can I pick up this issue?

Comment From: philwebb

@facewise Feel free to have a go, but we're not 100% sure how to fix it since we need to keep our build on Java 17. We might be able to use reflection to make the call to Console.isTerminal().

It's also going to be pretty hard to test. We might be able to create a testcontainers test, or we might just have to accept manual testing for now.

Please ask if you have any questions.

Comment From: facewise

@philwebb Is it OK to add a testcontainers test in spring-boot-tests/spring-boot-integration-tests?

It seems great to make a new test similar to tests in LoaderIntegrationTests.

Comment From: philwebb

@facewise That sounds fine, we can always move it around when we merge the code if we find a better long-term home.

Comment From: wilkinsona

I think we may be able to test it by reverting most of https://github.com/spring-projects/spring-boot/commit/8efdc1e46dc4168774b9a683ea7140770ae30ebc.