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.appender.rolling.action;


import org.apache.logging.log4j.core.Core;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;

 * {@link PathSorter} that sorts path by their LastModified attribute.
@Plugin(name = "SortByModificationTime", category = Core.CATEGORY_NAME, printObject = true)
public class PathSortByModificationTime implements PathSorter, Serializable {

    private static final long serialVersionUID = 1L;

    private final boolean recentFirst;
    private final int multiplier;

     * Constructs a new SortByModificationTime sorter.
     * @param recentFirst if true, most recently modified paths should come first
    public PathSortByModificationTime(final boolean recentFirst) {
        this.recentFirst = recentFirst;
        this.multiplier = recentFirst ? 1 : -1;

     * Create a PathSorter that sorts by lastModified time.
     * @param recentFirst if true, most recently modified paths should come first.
     * @return A PathSorter.
    public static PathSorter createSorter(
            @PluginAttribute(value = "recentFirst", defaultBoolean = true) final boolean recentFirst) {
        return new PathSortByModificationTime(recentFirst);

     * Returns whether this sorter sorts recent files first.
     * @return whether this sorter sorts recent files first
    public boolean isRecentFirst() {
        return recentFirst;

     * (non-Javadoc)
     * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
    public int compare(final PathWithAttributes path1, final PathWithAttributes path2) {
        final long lastModified1 = path1.getAttributes().lastModifiedTime().toMillis();
        final long lastModified2 = path2.getAttributes().lastModifiedTime().toMillis();
        int result = Long.signum(lastModified2 - lastModified1);
        if (result == 0) { // if same time compare paths lexicographically
            try {
                // assuming paths contain counters and dates, use reverse lexicographical order:
                // 20151129 before 20151128, path-2.log before path-1.log
                result = path2.getPath().compareTo(path1.getPath());
            } catch (final ClassCastException ex) {
                result = path2.getPath().toString().compareTo(path1.getPath().toString());
        return multiplier * result;



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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