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qos-ch / slf4j

Simple Logging Facade for Java
http://www.slf4j.org
MIT License
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Can we log the message to stdout when there is no provider available? #369

Open wkgcass opened 9 months ago

wkgcass commented 9 months ago

This is the default behavior since the very beginning of slf4j, including the latest slf4j-api:2.0.9:

When there's no provider available, slf4j prints an error message to stderr when the library is used for the first time and swallows all logging messages.

SLF4J: No SLF4J providers were found.
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See https://www.slf4j.org/codes.html#noProviders for further details.

Can we just log to stdout instead of swallowing the messages?

I know there's a slf4j-simple but it would be much easier to "combine" slf4j-api and slf4j-simple, or just log to stdout/stderr.

The graal native-image gives us an opportunity to build fast command line tools, which will use some existing java libraries. Since slf4j is widely used, a lot of libraries uses slf4j as their logging dependency.
However this requires us to include slf4j-simple for the projects which depend on these libraries.

This is ok for projects running on the server side since it would always need a logging impl anyway, but it's quite redundant for the command-line tools, and it would require extra configurations when building the native-image (we must ensure slf4j-simple accessible and can be used via reflection when building).

So can we consider to simply log to stdout when there is no provider available?

ceki commented 9 months ago

In response to issue 361 the Reporter class has been added. See commit 316b5d1727d647250ff791565650070094f5b85e and commit c12667b9063b2b9409ed49072d9746f34f968440

The Reporter class will be part of the next release.