Add StringFormat, MessageFormat, and RemoveUnnecessaryLogLevelGuards SLF4J recipes.#280
Merged
Merged
Conversation
RemoveUnnecessaryLogLevelGuards incorrectly removes guards around
logging calls that use string concatenation (e.g. `"Name: " + name`)
instead of parameterized `{}` placeholders. The guard is necessary
in these cases because concatenation is evaluated eagerly.
Validated at scale against the Default org where Netflix/ribbon had
two false positives in DiscoveryEnabledNIWSServerList and RestClient.
timtebeek
approved these changes
Feb 26, 2026
timtebeek
left a comment
Member
There was a problem hiding this comment.
Nice additions, thanks! I've added some polish mostly to use ListUtils and other ways to minimize the changeset.
This was referenced Feb 26, 2026
mergify Bot
added a commit
to robfrank/linklift
that referenced
this pull request
Mar 10, 2026
…rom 3.24.0 to 3.25.0 [skip ci] Bumps [org.openrewrite.recipe:rewrite-logging-frameworks](https://github.com/openrewrite/rewrite-logging-frameworks) from 3.24.0 to 3.25.0. Release notes *Sourced from [org.openrewrite.recipe:rewrite-logging-frameworks's releases](https://github.com/openrewrite/rewrite-logging-frameworks/releases).* > 3.25.0 > ------ > > What's Changed > -------------- > > * Add StringFormat, MessageFormat, and RemoveUnnecessaryLogLevelGuards SLF4J recipes. by [`@motlin`](https://github.com/motlin) in [openrewrite/rewrite-logging-frameworks#280](https://redirect.github.com/openrewrite/rewrite-logging-frameworks/pull/280) > * Fix PrintStackTraceToLogError breaking stacktrace-to-string methods by [`@timtebeek`](https://github.com/timtebeek) in [openrewrite/rewrite-logging-frameworks#282](https://redirect.github.com/openrewrite/rewrite-logging-frameworks/pull/282) > > **Full Changelog**: <openrewrite/rewrite-logging-frameworks@v3.24.0...v3.25.0> Commits * [`6618dfa`](openrewrite/rewrite-logging-frameworks@6618dfa) Fix PrintStackTraceToLogError breaking stacktrace-to-string methods ([#282](https://redirect.github.com/openrewrite/rewrite-logging-frameworks/issues/282)) * [`2f457be`](openrewrite/rewrite-logging-frameworks@2f457be) Add StringFormat, MessageFormat, and RemoveUnnecessaryLogLevelGuards SLF4J re... * See full diff in [compare view](openrewrite/rewrite-logging-frameworks@v3.24.0...v3.25.0) [](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores) Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`. [//]: # (dependabot-automerge-start) [//]: # (dependabot-automerge-end) --- Dependabot commands and options You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot show ignore conditions` will show all of the ignore conditions of the specified dependency - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
What's changed?
Add three new SLF4J recipes to
Slf4jBestPractices:StringFormatToParameterizedLogging— ReplacesString.format()calls in SLF4J logging statements with parameterized{}placeholders.MessageFormatToParameterizedLogging— ReplacesMessageFormat.format()calls in SLF4J logging statements with parameterized{}placeholders.RemoveUnnecessaryLogLevelGuards— Removesif (logger.isDebugEnabled())guards around SLF4J logging calls when parameterized logging makes them unnecessary.The
StringFormatandMessageFormatrecipes are ordered before the existingParameterizedLoggingrecipe inslf4j.ymlso that format calls are converted to parameterized logging first, beforeParameterizedLogginghandles string concatenation.What's your motivation?
String.format()andMessageFormat.format()defeat the purpose of SLF4J's parameterized logging by eagerly formatting the message regardless of log level. The existingParameterizedLoggingrecipe handles string concatenation but not these cases.Similarly, once logging statements use parameterized
{}placeholders, explicitisDebugEnabled()/isTraceEnabled()guards become unnecessary boilerplate since SLF4J defers argument evaluation.Anything in particular you'd like reviewers to focus on?
RemoveUnnecessaryLogLevelGuardsrecipe only removes guards when all logging calls inside the guard body use parameterized logging (no string concatenation or method calls other than toString()).Anyone you would like to review specifically?
@timtebeek saw these recipes as I was developing them in Liftwizard:
Have you considered any alternatives or workarounds?
I considered splitting this into two PRs and I could still do that if preferred.
Any additional context
Checklist