Re: [PROPOSAL] Migrate Commons JEXL from Commons Logging to SLF4J

-1: If we switch to anything, we should switch to log4j-api, it's just
better.

Gary

On Fri, Dec 19, 2025, 03:59 单红宇 <[email protected]> wrote:

> Dear Apache Commons JEXL developers,
>
>
> I'm writing to propose migrating the Commons JEXL project from Apache
> Commons Logging
>
> to SLF4J as the default logging facade.
>
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> -----------------------------------------------------------------------------------------
>
> Apache Commons JEXL currently uses Apache Commons Logging as its default
> logging framework. While Commons Logging has served well historically, the
> Java logging landscape has evolved significantly. Many modern frameworks
> and applications now prefer and default to SLF4J (Simple Logging Facade for
> Java).
>
> Why SLF4J is Recommended:
>
>
> Modern Ecosystem Alignment: Most contemporary Java frameworks (Spring
> Boot, Hibernate, etc.) have migrated to or recommend SLF4J as their logging
> facade.
>
>
>
> Superior Performance: SLF4J's parameterized logging (logger.debug("User {}
> logged in", username)) avoids the string concatenation overhead required by
> Commons Logging's isDebugEnabled() pattern.
>
>
>
> Flexible Backend Support: SLF4J supports multiple logging implementations
> (Logback, Log4j2, JDK logging) without requiring code changes.
>
>
>
> Better API Design: SLF4J provides a cleaner API with no checked exceptions
> and supports MDC (Mapped Diagnostic Context) for advanced logging scenarios.
>
>
>
> Industry Standard: SLF4J has become the de facto standard for logging
> facades in modern Java applications.
>
>
> Migration Benefits for JEXL:
>
> Better Integration: Projects using SLF4J won't need bridging dependencies
> when using JEXL.
>
> Performance Improvements: Parameterized logging in SLF4J can provide
> performance benefits.
>
> Future-Proofing: Aligns JEXL with modern Java development practices.
>
> Backward Compatibility: Existing projects can continue using Commons
> Logging via SLF4J's bridge (jcl-over-slf4j).
>
> Proposed Approach:
>
> Replace Commons Logging dependencies with SLF4J API
>
> Update code to use SLF4J's parameterized logging patterns
>
> Provide backward compatibility documentation
>
> Backward Compatibility Note: SLF4J provides excellent backward
> compatibility. Projects currently using JEXL with Commons Logging can
> simply add the jcl-over-slf4j bridge dependency to route all Commons
> Logging calls through SLF4J without changing their logging configuration.
>
> Willingness to Contribute: If the maintainers agree with this proposal, I
> would be happy to contribute the necessary code changes via a pull request.
> This would include:
>
> Dependency updates in pom.xml
>
> Code migration from Commons Logging to SLF4J patterns
>
> Documentation updates
>
> Test verification
>
> References:
>
> SLF4J Manual: http://www.slf4j.org/manual.html
>
> Migration Guide: http://www.slf4j.org/legacy.html
>
> jcl-over-slf4j&nbsp;bridge: Provides transparent redirection of Commons
> Logging calls to SLF4J
>
> Thank you for considering this proposal to modernize JEXL's logging
> infrastructure.
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> 单红宇
> [email protected]