Source Code for Apache Log4j Core Implementation

Apache Log4j Core Implementation provides the functional components of the logging system. Users are free to create their own plugins and include them in the logging configuration. Apache Log4j Core is a required module to use Apache Log4j.

Bytecode (Java 8) for Apache Log4j Core Implementation is provided in a separate JAR file like log4j-core-2.14.1.jar.

Source Code files for Apache Log4j API are provided in both binary packge like and source package like You can download them at Apache Log4j Website.

You can also browse Source Code files for Apache Log4j Core Implementation 2.14.1 below.



 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache license, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * See the license for the specific language governing permissions and
 * limitations under the license.
package org.apache.logging.log4j.core.async;


import org.apache.logging.log4j.core.LoggerContext;
import org.apache.logging.log4j.core.selector.ClassLoaderContextSelector;
import org.apache.logging.log4j.core.util.Constants;
import org.apache.logging.log4j.util.PropertiesUtil;

 * {@code ContextSelector} that manages {@code AsyncLoggerContext} instances.
 * <p>
 * As of version 2.5, this class extends ClassLoaderContextSelector for better web app support.
public class AsyncLoggerContextSelector extends ClassLoaderContextSelector {

     * Returns {@code true} if the user specified this selector as the Log4jContextSelector, to make all loggers
     * asynchronous.
     * @return {@code true} if all loggers are asynchronous, {@code false} otherwise.
    public static boolean isSelected() {
        return AsyncLoggerContextSelector.class.getName().equals(

    protected LoggerContext createContext(final String name, final URI configLocation) {
        return new AsyncLoggerContext(name, null, configLocation);

    protected String toContextMapKey(final ClassLoader loader) {
        // LOG4J2-666 ensure unique name across separate instances created by webapp classloaders
        return "AsyncContext@" + Integer.toHexString(System.identityHashCode(loader));

    protected String defaultContextName() {
        return "DefaultAsyncContext@" + Thread.currentThread().getName();



Or download all of them as a single archive file:

File name: log4j-core-2.14.1-sources.jar
File size: 1281358 bytes
Release date: 2021-03-06


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