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.lookup;

import java.util.Objects;

import javax.naming.NamingException;

import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.Marker;
import org.apache.logging.log4j.MarkerManager;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.status.StatusLogger;

 * Looks up keys from JNDI resources.
@Plugin(name = "jndi", category = StrLookup.CATEGORY)
public class JndiLookup extends AbstractLookup {

    private static final Logger LOGGER = StatusLogger.getLogger();
    private static final Marker LOOKUP = MarkerManager.getMarker("LOOKUP");

    /** JNDI resource path prefix used in a J2EE container */
    static final String CONTAINER_JNDI_RESOURCE_PATH_PREFIX = "java:comp/env/";

     * Looks up the value of the JNDI resource.
     * @param event The current LogEvent (is ignored by this StrLookup).
     * @param key  the JNDI resource name to be looked up, may be null
     * @return The String value of the JNDI resource.
    public String lookup(final LogEvent event, final String key) {
        if (key == null) {
            return null;
        final String jndiName = convertJndiName(key);
        try (final JndiManager jndiManager = JndiManager.getDefaultManager()) {
            return Objects.toString(jndiManager.lookup(jndiName), null);
        } catch (final NamingException e) {
            LOGGER.warn(LOOKUP, "Error looking up JNDI resource [{}].", jndiName, e);
            return null;

     * Convert the given JNDI name to the actual JNDI name to use.
     * Default implementation applies the "java:comp/env/" prefix
     * unless other scheme like "java:" is given.
     * @param jndiName The name of the resource.
     * @return The fully qualified name to look up.
    private String convertJndiName(final String jndiName) {
        if (!jndiName.startsWith(CONTAINER_JNDI_RESOURCE_PATH_PREFIX) && jndiName.indexOf(':') == -1) {
            return CONTAINER_JNDI_RESOURCE_PATH_PREFIX + jndiName;
        return jndiName;



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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