How to Check Log4j Version?

To check the version of Log4j used in your application or environment, there are several reliable methods depending on how Log4j is being used — whether it's bundled in a Java application, part of a dependency in a build tool like Maven or Gradle, or deployed within a web server or JAR file.

There are several ways to check the version of Log4j you are using in your Java application:

1. Check Build Files (Maven/Gradle)

• Open pom.xml (for Maven) or build.gradle (for Gradle).
• Look for log4j-core, log4j-api, or similar dependencies with version numbers.

2. Inspect JAR File Names

• Go to your app’s lib or deployment folder.
• Look for files like log4j-core-2.17.1.jar — the version is in the filename.

3. Check Inside JAR Files

• Use a tool to open the JAR file.
• Look for META-INF/MANIFEST.MF or pom.properties — they often contain version details.

4. Review Application Logs

• Some apps log the Log4j version on startup (e.g., Apache Log4j 2.x.x initialized).

5. Use IDE or Dependency Viewers

• If you're using IntelliJ or Eclipse, check the project’s external libraries or dependency tree to find the resolved version.

6. For Deployed Apps (Tomcat, JBoss, etc.)

• Navigate to WEB-INF/lib in your deployed WAR/EAR files.
• Inspect the JARs inside for version numbers.

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