Migrate Log4j to SLF4J

org.openrewrite.java.logging.slf4j.Log4jToSlf4j
Migrates usage of Apache Log4j to using SLF4J directly. Use of the traditional Log4j to SLF4J bridge can result in loss of performance, as the Log4j messages must be formatted before they can be passed to SLF4J. Note, this currently does not modify log4j.properties files.
Tags
slf4j
logging
log4j
Source
​Github, Issue Tracker, Maven Central​
groupId: org.openrewrite.recipe
artifactId: rewrite-logging-frameworks
version: 1.20.1
Contributors
​Tim te Beek​
​Kun Li​
​Patrick​
​traceyyoshima​
Usage
This recipe has no required configuration options. It can be activated by adding a dependency on org.openrewrite.recipe:rewrite-logging-frameworks:1.20.1 in your build file or by running a shell command (in which case no build changes are needed):
Gradle
Maven POM
Maven Command Line
build.gradle
plugins {
    id("org.openrewrite.rewrite") version("5.40.4")
}
​
rewrite {
    activeRecipe("org.openrewrite.java.logging.slf4j.Log4jToSlf4j")
}
​
repositories {
    mavenCentral()
}
​
dependencies {
    rewrite("org.openrewrite.recipe:rewrite-logging-frameworks:1.20.1")
}
pom.xml
<project>
  <build>
    <plugins>
      <plugin>
        <groupId>org.openrewrite.maven</groupId>
        <artifactId>rewrite-maven-plugin</artifactId>
        <version>4.45.0</version>
        <configuration>
          <activeRecipes>
            <recipe>org.openrewrite.java.logging.slf4j.Log4jToSlf4j</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-logging-frameworks</artifactId>
            <version>1.20.1</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>
shell
mvn -U org.openrewrite.maven:rewrite-maven-plugin:run \
  -Drewrite.recipeArtifactCoordinates=org.openrewrite.recipe:rewrite-logging-frameworks:RELEASE \
  -Drewrite.activeRecipes=org.openrewrite.java.logging.slf4j.Log4jToSlf4j
Definition
Recipe List
Yaml Recipe List
​Migrate Log4j 1.x to SLF4J 1.x​
​Loggers should be named for their enclosing classes​
​Remove Maven dependency​
groupId: org.apache.logging.log4j
artifactId: log4j-to-slf4j
​Upgrade Maven dependency version​
groupId: org.apache.logging.log4j
artifactId: log4j-api
newVersion: latest.release
overrideManagedVersion: true
​Upgrade Maven dependency version​
groupId: org.apache.logging.log4j
artifactId: log4j-core
newVersion: latest.release
overrideManagedVersion: true
​Add Maven dependency​
groupId: org.slf4j
artifactId: slf4j-api
version: latest.release
onlyIfUsing: org.apache.logging.log4j.*
​Add Maven dependency​
groupId: org.apache.logging.log4j
artifactId: log4j-slf4j-impl
version: latest.release
onlyIfUsing: org.apache.logging.log4j.*
​Add Maven dependency​
groupId: org.slf4j
artifactId: slf4j-api
version: latest.release
onlyIfUsing: org.apache.log4j.*
​Add Maven dependency​
groupId: org.apache.logging.log4j
artifactId: log4j-slf4j-impl
version: latest.release
onlyIfUsing: org.apache.log4j.*
---
type: specs.openrewrite.org/v1beta/recipe
name: org.openrewrite.java.logging.slf4j.Log4jToSlf4j
displayName: Migrate Log4j to SLF4J
description: Migrates usage of Apache Log4j to using SLF4J directly. Use of the traditional Log4j to SLF4J bridge can result in loss of performance, as the Log4j messages must be formatted before they can be passed to SLF4J. Note, this currently does not modify `log4j.properties` files.
tags:
  - slf4j
  - logging
  - log4j
recipeList:
  - org.openrewrite.java.logging.slf4j.Log4j1ToSlf4j1
  - org.openrewrite.java.logging.slf4j.LoggersNamedForEnclosingClass
  - org.openrewrite.maven.RemoveDependency:
      groupId: org.apache.logging.log4j
      artifactId: log4j-to-slf4j
  - org.openrewrite.maven.UpgradeDependencyVersion:
      groupId: org.apache.logging.log4j
      artifactId: log4j-api
      newVersion: latest.release
      overrideManagedVersion: true
  - org.openrewrite.maven.UpgradeDependencyVersion:
      groupId: org.apache.logging.log4j
      artifactId: log4j-core
      newVersion: latest.release
      overrideManagedVersion: true
  - org.openrewrite.maven.AddDependency:
      groupId: org.slf4j
      artifactId: slf4j-api
      version: latest.release
      onlyIfUsing: org.apache.logging.log4j.*
  - org.openrewrite.maven.AddDependency:
      groupId: org.apache.logging.log4j
      artifactId: log4j-slf4j-impl
      version: latest.release
      onlyIfUsing: org.apache.logging.log4j.*
  - org.openrewrite.maven.AddDependency:
      groupId: org.slf4j
      artifactId: slf4j-api
      version: latest.release
      onlyIfUsing: org.apache.log4j.*
  - org.openrewrite.maven.AddDependency:
      groupId: org.apache.logging.log4j
      artifactId: log4j-slf4j-impl
      version: latest.release
      onlyIfUsing: org.apache.log4j.*
​
See how this recipe works across multiple open-source repositories
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Parameterize SLF4J logging statements
Last modified 23d ago