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 com.lmax.disruptor.LifecycleAware;
import com.lmax.disruptor.Sequence;
import com.lmax.disruptor.SequenceReportingEventHandler;

 * This event handler gets passed messages from the RingBuffer as they become
 * available. Processing of these messages is done in a separate thread,
 * controlled by the {@code Executor} passed to the {@code Disruptor}
 * constructor.
public class RingBufferLogEventHandler implements
        SequenceReportingEventHandler<RingBufferLogEvent>, LifecycleAware {

    private static final int NOTIFY_PROGRESS_THRESHOLD = 50;
    private Sequence sequenceCallback;
    private int counter;
    private long threadId = -1;

    public void setSequenceCallback(final Sequence sequenceCallback) {
        this.sequenceCallback = sequenceCallback;

    public void onEvent(final RingBufferLogEvent event, final long sequence,
            final boolean endOfBatch) throws Exception {
        try {
        finally {
            // notify the BatchEventProcessor that the sequence has progressed.
            // Without this callback the sequence would not be progressed
            // until the batch has completely finished.

    private void notifyCallback(long sequence) {
        if (++counter > NOTIFY_PROGRESS_THRESHOLD) {
            counter = 0;

     * Returns the thread ID of the background consumer thread, or {@code -1} if the background thread has not started
     * yet.
     * @return the thread ID of the background consumer thread, or {@code -1}
    public long getThreadId() {
        return threadId;

    public void onStart() {
        threadId = Thread.currentThread().getId();

    public void onShutdown() {



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


Source Code for Apache Log4j JDK Logging Adapter

Source Code for Apache Log4j API

Downloading and Reviewing Apache Log4j Packages

⇑⇑ FAQ for Apache Log4j

2015-11-03, 92331👍, 0💬