Hardens PropertiesUtil against recursive property sources

[ppkarwasz]

As showed in #3252, Spring's JndiPropertySource not only can throw exceptions, but can also perform logging calls. Such a call causes a recursive call to PropertiesUtil.getProperty("log4j2.flowMessageFactory") and a StackOverflowException in the best scenario. The worst scenario includes a deadlock.

This PR:

• Moves the creation of the default MessageFactory and FlowMessageFactory to the static initializer of LoggerContext. This should be close enough to the pre-2.23.0 location in AbstractLogger. The LoggerContext class is usually initialized, before Spring Boot adds its property sources to PropertiesUtil.
• Adds a check to PropertiesUtil to ignore recursive calls.

Closes #3252.

[sundaybluesky]

Hi @ppkarwasz,

Can you please consider change back AsyncLogger constructor package-private access back to public? I've extended AsyncLogger class with the same package name to build a customized AsyncLogger and use reflection to initial customized AsyncLogger. This code was working for more than 7 years and blocked in 2.24.3 with this PR code change.

Thanks,
sundaybluesky

[ppkarwasz]

Hi @sundaybluesky,

Can you please consider change back AsyncLogger constructor package-private access back to public?

Sure, please open a new feature request. In the new feature request, can you explain how are you using AsyncLogger. It is entirely possible that there are already public APIs that allow you to do what you are doing. For example AsyncLoggerContext.newLogger() allows you to create a new AsyncLogger without any reflection.

This code was working for more than 7 years and blocked in 2.24.3 with this PR code change.

That is the problem with using reflection to access private methods or classes like AsyncLoggerDisruptor: the class or method can disappear without notice.

Note: As far as I understand you called the constructor of AsyncLogger through reflection. You can still do it, but you need to make it accessible first.

[sundaybluesky]

Hi @ppkarwasz ,

Thanks for you quick response. I created #3527 to track this issue, please help to take a look.

Regards,
sundaybluesky