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 apache-log4j-2.14.1-bin.zip and source package like apache-log4j-2.14.1-src.zip. You can download them at Apache Log4j Website.

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

⏎ org/apache/logging/log4j/core/config/DefaultConfiguration.java

/*
 * 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
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the license for the specific language governing permissions and
 * limitations under the license.
 */
package org.apache.logging.log4j.core.config;

/**
 * The default configuration writes all output to the Console using the default logging level. You configure default
 * logging level by setting the system property "org.apache.logging.log4j.level" to a level name. If you do not
 * specify the property, Log4j uses the ERROR Level. Log Events will be printed using the basic formatting provided
 * by each Message.
 */
public class DefaultConfiguration extends AbstractConfiguration {

    /**
     * The name of the default configuration.
     */
    public static final String DEFAULT_NAME = "Default";

    /**
     * The System Property used to specify the logging level.
     */
    public static final String DEFAULT_LEVEL = "org.apache.logging.log4j.level";

    /**
     * The default Pattern used for the default Layout.
     */
    public static final String DEFAULT_PATTERN = "%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n";

    /**
     * Constructor to create the default configuration.
     */
    public DefaultConfiguration() {
        super(null, ConfigurationSource.NULL_SOURCE);
        setToDefault();
    }

    @Override
    protected void doConfigure() {
    }
}

⏎ org/apache/logging/log4j/core/config/DefaultConfiguration.java

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
Download 

⇒ Source Code for Apache Log4j JDK Logging Adapter

⇐ Source Code for Apache Log4j API

⇑ Downloading and Reviewing Apache Log4j Packages

⇑⇑ FAQ for Apache Log4j