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Migrate Log4j 2.x to SLF4J 1.x

org.openrewrite.java.logging.slf4j.Log4j2ToSlf4j1
Transforms usages of Log4j 2.x to leveraging SLF4J 1.x directly. Note, this currently does not modify log4j.properties files.
Tags
slf4j
logging
log4j
Recipe source
​GitHub, Issue Tracker, Maven Central​
groupId: org.openrewrite.recipe
artifactId: rewrite-logging-frameworks
version: 2.1.0
This recipe is composed of more than one recipe. If you want to customize the set of recipes this is composed of, you can find and copy the GitHub source for the recipe from the link above.
Usage
This recipe has no required configuration options. It can be activated by adding a dependency on org.openrewrite.recipe:rewrite-logging-frameworks:2.1.0 in your build file or by running a shell command (in which case no build changes are needed):
Gradle
Gradle init script
Maven POM
Maven Command Line
Moderne CLI
1.Add the following to your build.gradle file:
build.gradle
plugins {
    id("org.openrewrite.rewrite") version("6.5.6")
}
​
rewrite {
    activeRecipe("org.openrewrite.java.logging.slf4j.Log4j2ToSlf4j1")
}
​
repositories {
    mavenCentral()
}
​
dependencies {
    rewrite("org.openrewrite.recipe:rewrite-logging-frameworks:2.1.0")
}
2.Run gradle rewriteRun to run the recipe.
1.Create a file named init.gradle in the root of your project.
init.gradle
initscript {
    repositories {
        maven { url "https://plugins.gradle.org/m2" }
    }
    dependencies { classpath("org.openrewrite:plugin:6.5.6") }
}
rootProject {
    plugins.apply(org.openrewrite.gradle.RewritePlugin)
    dependencies {
        rewrite("org.openrewrite.recipe:rewrite-logging-frameworks:2.1.0")
    }
    rewrite {
        activeRecipe("org.openrewrite.java.logging.slf4j.Log4j2ToSlf4j1")
    }
    afterEvaluate {
        if (repositories.isEmpty()) {
            repositories {
                mavenCentral()
            }
        }
    }
}
2.Run gradle --init-script init.gradle rewriteRun to run the recipe.
1.Add the following to your pom.xml file:
pom.xml
<project>
  <build>
    <plugins>
      <plugin>
        <groupId>org.openrewrite.maven</groupId>
        <artifactId>rewrite-maven-plugin</artifactId>
        <version>5.13.0</version>
        <configuration>
          <activeRecipes>
            <recipe>org.openrewrite.java.logging.slf4j.Log4j2ToSlf4j1</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-logging-frameworks</artifactId>
            <version>2.1.0</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>
2.Run mvn rewrite:run to run the recipe.
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.Log4j2ToSlf4j1
You will need to have configured the Moderne CLI on your machine before you can run the following command.
shell
mod run . --recipe Log4j2ToSlf4j1
Definition
Recipe List
Yaml Recipe List
​Change type​
oldFullyQualifiedTypeName: org.apache.logging.log4j.LogManager
newFullyQualifiedTypeName: org.slf4j.LoggerFactory
​Change method name​
methodPattern: org.apache.logging.log4j.Logger fatal(..)
newMethodName: error
​Change method name​
methodPattern: org.apache.logging.log4j.Category fatal(..)
newMethodName: error
​Change type​
oldFullyQualifiedTypeName: org.apache.logging.log4j.Logger
newFullyQualifiedTypeName: org.slf4j.Logger
​org.openrewrite.java.logging.slf4j.ParameterizedLogging​
---
type: specs.openrewrite.org/v1beta/recipe
name: org.openrewrite.java.logging.slf4j.Log4j2ToSlf4j1
displayName: Migrate Log4j 2.x to SLF4J 1.x
description: Transforms usages of Log4j 2.x to leveraging SLF4J 1.x directly. Note, this currently does not modify `log4j.properties` files.
tags:
  - slf4j
  - logging
  - log4j
recipeList:
  - org.openrewrite.java.ChangeType:
      oldFullyQualifiedTypeName: org.apache.logging.log4j.LogManager
      newFullyQualifiedTypeName: org.slf4j.LoggerFactory
  - org.openrewrite.java.ChangeMethodName:
      methodPattern: org.apache.logging.log4j.Logger fatal(..)
      newMethodName: error
  - org.openrewrite.java.ChangeMethodName:
      methodPattern: org.apache.logging.log4j.Category fatal(..)
      newMethodName: error
  - org.openrewrite.java.ChangeType:
      oldFullyQualifiedTypeName: org.apache.logging.log4j.Logger
      newFullyQualifiedTypeName: org.slf4j.Logger
  - org.openrewrite.java.logging.slf4j.ParameterizedLogging
​
See how this recipe works across multiple open-source repositories
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​​
The community edition of the Moderne platform enables you to easily run recipes across thousands of open-source repositories.
Please contact Moderne for more information about safely running the recipes on your own codebase in a private SaaS.
Contributors
Aaron Gershman, Patrick, Knut Wannheden, Jonathan Schnéider, Sam Snyder​
Migrate Log4j 1.x to SLF4J 1.x
Migrate Log4j to SLF4J
Last modified 9d ago