tree: 931b5cca0dfdf06342254a70a97e454e4efb96f5 [path history] [tgz]
  1. .asf.yaml
  2. .dockerignore
  3. .gitattributes
  4. .github/
  5. .gitignore
  6. .mvn/
  9. Dockerfile
  10. LICENSE.txt
  11. NOTICE.txt
  15. checkstyle-header.txt
  16. checkstyle-import-control.xml
  17. checkstyle-suppressions.xml
  18. checkstyle.xml
  19. log4j-1.2-api/
  20. log4j-api/
  21. log4j-appserver/
  22. log4j-bom/
  23. log4j-cassandra/
  24. log4j-core-its/
  25. log4j-core/
  26. log4j-couchdb/
  27. log4j-csv/
  28. log4j-distribution/
  29. log4j-docker/
  30. log4j-flume-ng/
  31. log4j-gctests/
  32. log4j-iostreams/
  33. log4j-jcl/
  34. log4j-jdbc-dbcp2/
  35. log4j-jdbc/
  36. log4j-jeromq/
  37. log4j-jms/
  38. log4j-jmx-gui/
  39. log4j-jpa/
  40. log4j-jpl/
  41. log4j-jul/
  42. log4j-kafka/
  43. log4j-kubernetes/
  44. log4j-layout-jackson-json/
  45. log4j-layout-jackson-xml/
  46. log4j-layout-jackson-yaml/
  47. log4j-layout-jackson/
  48. log4j-layout-template-json/
  49. log4j-liquibase/
  50. log4j-mongodb3/
  51. log4j-mongodb4/
  52. log4j-osgi/
  53. log4j-perf/
  54. log4j-plugins/
  55. log4j-redis/
  56. log4j-samples/
  57. log4j-slf4j-impl/
  58. log4j-slf4j18-impl/
  59. log4j-smtp/
  60. log4j-spring-boot/
  61. log4j-spring-cloud-config/
  62. log4j-taglib/
  63. log4j-to-slf4j/
  64. log4j-web/
  65. mvnw
  66. mvnw.cmd
  67. pom.xml
  68. spotbugs-exclude-filter.xml
  69. src/
  70. toolchains-docker.xml
  71. toolchains-sample-linux.xml
  72. toolchains-sample-mac.xml
  73. toolchains-sample-win.xml

Apache Log4j 2

Apache Log4j 2 is an upgrade to Log4j that provides significant improvements over its predecessor, Log4j 1.x, and provides many of the improvements available in Logback while fixing some inherent problems in Logback's architecture.

Jenkins build (3.x) Jenkins build (2.x) GitHub build (3.x) GitHub build (2.x) Latest Maven Central release

Pull Requests on Github

By sending a pull request you grant the Apache Software Foundation sufficient rights to use and release the submitted work under the Apache license. You grant the same rights (copyright license, patent license, etc.) to the Apache Software Foundation as if you have signed a Contributor License Agreement. For contributions that are judged to be non-trivial, you will be asked to actually sign a Contributor License Agreement.


Users should refer to Maven, Ivy, Gradle, and SBT Artifacts on the Log4j web site for instructions on how to include Log4j into their project using their chosen build tool.

Basic usage of the Logger API:

package com.example;

import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;

public class Example {
    private static final Logger LOGGER = LogManager.getLogger();

    public static void main(String... args) {
        String thing = args.length > 0 ? args[0] : "world";"Hello, {}!", thing);
        LOGGER.debug("Got calculated value only if debug enabled: {}", () -> doSomeCalculation());

    private static Object doSomeCalculation() {
        // do some complicated calculation

And an example log4j2.xml configuration file:

<?xml version="1.0" encoding="UTF-8"?>
    <Console name="Console" target="SYSTEM_OUT">
      <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n"/>
    <Logger name="com.example" level="INFO"/>
    <Root level="error">
      <AppenderRef ref="Console"/>


The Log4j 2 User's Guide is available here or as a downloadable PDF.


Log4j 2.4 and greater requires Java 7, versions 2.0-alpha1 to 2.3 required Java 6. Some features require optional dependencies; the documentation for these features specifies the dependencies.


Apache Log4j 2 is distributed under the Apache License, version 2.0.


How to download Log4j, and how to use it from Maven, Ivy and Gradle. You can access the latest development snapshot by using the Maven repository, see Snapshot builds.

Issue Tracking

Issues, bugs, and feature requests should be submitted to the JIRA issue tracking system for this project.

Pull requests on GitHub are welcome, but please open a ticket in the JIRA issue tracker first, and mention the JIRA issue in the Pull Request.

Building From Source

Log4j requires Apache Maven 3.x. To build from source and install to your local Maven repository, execute the following:

mvn install


We love contributions! Take a look at our contributing page.