Migrate Log4j 2.x to Logback

org.openrewrite.java.logging.logback.Log4jToLogback

Migrates usage of Apache Log4j 2.x to using logback as an SLF4J implementation directly. Note, this currently does not modify log4j.properties files.

Tags

• logging

• log4j

• logback

Recipe source

GitHub, Issue Tracker, Maven Central

• groupId: org.openrewrite.recipe

• artifactId: rewrite-logging-frameworks

• version: 2.6.0

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:2.6.0 in your build file or by running a shell command (in which case no build changes are needed):

Gradle

1. Add the following to your build.gradle file:

build.gradle

plugins {
    id("org.openrewrite.rewrite") version("6.12.0")
}

rewrite {
    activeRecipe("org.openrewrite.java.logging.logback.Log4jToLogback")
}

repositories {
    mavenCentral()
}

dependencies {
    rewrite("org.openrewrite.recipe:rewrite-logging-frameworks:2.6.0")
}

2. Run gradle rewriteRun to run the recipe.

Gradle init script

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:6.12.0") }
}
rootProject {
    plugins.apply(org.openrewrite.gradle.RewritePlugin)
    dependencies {
        rewrite("org.openrewrite.recipe:rewrite-logging-frameworks:2.6.0")
    }
    rewrite {
        activeRecipe("org.openrewrite.java.logging.logback.Log4jToLogback")
    }
    afterEvaluate {
        if (repositories.isEmpty()) {
            repositories {
                mavenCentral()
            }
        }
    }
}

2. Run gradle --init-script init.gradle rewriteRun to run the recipe.

Maven POM

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>5.29.0</version>
        <configuration>
          <activeRecipes>
            <recipe>org.openrewrite.java.logging.logback.Log4jToLogback</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-logging-frameworks</artifactId>
            <version>2.6.0</version>
          </dependency>
        </dependencies>
      </plugin>
    </plugins>
  </build>
</project>

2. Run mvn rewrite:run to run the recipe.

Maven Command Line

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.logback.Log4jToLogback

Moderne CLI

You will need to have configured the Moderne CLI on your machine before you can run the following command.

shell

mod run . --recipe Log4jToLogback

Definition

Recipe List

• Migrate Log4j to SLF4J

• Migrate Log4j 2.x Appender to logback-classic equivalents

• Migrate Log4j 2.x Layout to logback-classic equivalents

• Add Gradle or Maven dependency

  • groupId: ch.qos.logback

  • artifactId: logback-core

  • version: latest.release

  • onlyIfUsing: org.apache.logging.log4j.*

• Add Gradle or Maven dependency

  • groupId: ch.qos.logback

  • artifactId: logback-classic

  • version: latest.release

  • onlyIfUsing: org.apache.logging.log4j.*

• Add Gradle or Maven dependency

  • groupId: org.slf4j

  • artifactId: slf4j-api

  • version: latest.release

  • onlyIfUsing: org.apache.logging.log4j.*

• Remove a Gradle or Maven dependency

  • groupId: org.apache.logging.log4j

  • artifactId: log4j-*

Yaml Recipe List

---
type: specs.openrewrite.org/v1beta/recipe
name: org.openrewrite.java.logging.logback.Log4jToLogback
displayName: Migrate Log4j 2.x to Logback
description: Migrates usage of Apache Log4j 2.x to using `logback` as an SLF4J implementation directly. Note, this currently does not modify `log4j.properties` files.
tags:
  - logging
  - log4j
  - logback
recipeList:
  - org.openrewrite.java.logging.slf4j.Log4jToSlf4j
  - org.openrewrite.java.logging.logback.Log4jAppenderToLogback
  - org.openrewrite.java.logging.logback.Log4jLayoutToLogback
  - org.openrewrite.java.dependencies.AddDependency:
      groupId: ch.qos.logback
      artifactId: logback-core
      version: latest.release
      onlyIfUsing: org.apache.logging.log4j.*
  - org.openrewrite.java.dependencies.AddDependency:
      groupId: ch.qos.logback
      artifactId: logback-classic
      version: latest.release
      onlyIfUsing: org.apache.logging.log4j.*
  - org.openrewrite.java.dependencies.AddDependency:
      groupId: org.slf4j
      artifactId: slf4j-api
      version: latest.release
      onlyIfUsing: org.apache.logging.log4j.*
  - org.openrewrite.java.dependencies.RemoveDependency:
      groupId: org.apache.logging.log4j
      artifactId: log4j-*

See how this recipe works across multiple open-source repositories

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Please contact Moderne for more information about safely running the recipes on your own codebase in a private SaaS.

Contributors

Aaron Gershman, Patrick, Sam Snyder, Knut Wannheden, Tim te Beek, Adriano Machado, Jonathan Schnéider, Tim te Beek, Jonathan Schneider, Patrick Way, Kun Li, Peter Streef, Aaron Gershman