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/Configurator.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;

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.core.LoggerContext;
import org.apache.logging.log4j.core.impl.Log4jContextFactory;
import org.apache.logging.log4j.core.util.NetUtils;
import org.apache.logging.log4j.spi.LoggerContextFactory;
import org.apache.logging.log4j.status.StatusLogger;
import org.apache.logging.log4j.util.Strings;

import java.net.URI;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;

/**
 * Initializes and configure the Logging system. This class provides several ways to construct a LoggerContext using
 * the location of a configuration file, a context name, and various optional parameters.
 */
public final class Configurator {

    private static final String FQCN = Configurator.class.getName();

    private static final Logger LOGGER = StatusLogger.getLogger();

    private static Log4jContextFactory getFactory() {
        final LoggerContextFactory factory = LogManager.getFactory();
        if (factory instanceof Log4jContextFactory) {
            return (Log4jContextFactory) factory;
        } else {
            if (factory != null) {
                LOGGER.error("LogManager returned an instance of {} which does not implement {}. Unable to initialize Log4j.",
                        factory.getClass().getName(), Log4jContextFactory.class.getName());
            } else {
                LOGGER.fatal("LogManager did not return a LoggerContextFactory. This indicates something has gone terribly wrong!");
            }
            return null;
        }
    }

    /**
     * Initializes the Logging Context.
     * @param loader The ClassLoader for the Context (or null).
     * @param source The InputSource for the configuration.
     * @return The LoggerContext.
     */
    public static LoggerContext initialize(final ClassLoader loader,
                                           final ConfigurationSource source) {
        return initialize(loader, source, null);
    }

    /**
     * Initializes the Logging Context.
     * @param loader The ClassLoader for the Context (or null).
     * @param source The InputSource for the configuration.
     * @param externalContext The external context to be attached to the LoggerContext.
     * @return The LoggerContext.
     */

    public static LoggerContext initialize(final ClassLoader loader,
                                           final ConfigurationSource source,
                                           final Object externalContext)
    {

        try {
            final Log4jContextFactory factory = getFactory();
            return factory == null ? null :
                    factory.getContext(FQCN, loader, externalContext, false, source);
        } catch (final Exception ex) {
            LOGGER.error("There was a problem obtaining a LoggerContext using the configuration source [{}]", source, ex);
        }
        return null;
    }

    /**
     * Initializes the Logging Context.
     * @param name The Context name.
     * @param loader The ClassLoader for the Context (or null).
     * @param configLocation The configuration for the logging context.
     * @return The LoggerContext or null if an error occurred (check the status logger).
     */
    public static LoggerContext initialize(final String name, final ClassLoader loader, final String configLocation) {
        return initialize(name, loader, configLocation, null);

    }

    /**
     * Initializes the Logging Context.
     * @param name The Context name.
     * @param loader The ClassLoader for the Context (or null).
     * @param configLocation The configuration for the logging context (or null, or blank).
     * @param externalContext The external context to be attached to the LoggerContext
     * @return The LoggerContext or null if an error occurred (check the status logger).
     */
    public static LoggerContext initialize(final String name, final ClassLoader loader, final String configLocation,
            final Object externalContext) {
        if (Strings.isBlank(configLocation)) {
            return initialize(name, loader, (URI) null, externalContext);
        }
        if (configLocation.contains(",")) {
            final String[] parts = configLocation.split(",");
            String scheme = null;
            final List<URI> uris = new ArrayList<>(parts.length);
            for (final String part : parts) {
                final URI uri = NetUtils.toURI(scheme != null ? scheme + ":" + part.trim() : part.trim());
                if (scheme == null && uri.getScheme() != null) {
                    scheme = uri.getScheme();
                }
                uris.add(uri);
            }
            return initialize(name, loader, uris, externalContext);
        }
        return initialize(name, loader, NetUtils.toURI(configLocation), externalContext);
    }

    /**
     * Initializes the Logging Context.
     * @param name The Context name.
     * @param loader The ClassLoader for the Context (or null).
     * @param configLocation The configuration for the logging context.
     * @return The LoggerContext.
     */
    public static LoggerContext initialize(final String name, final ClassLoader loader, final URI configLocation) {
        return initialize(name, loader, configLocation, null);
    }

    /**
     * Initializes the Logging Context.
     * @param name The Context name.
     * @param loader The ClassLoader for the Context (or null).
     * @param configLocation The configuration for the logging context (or null).
     * @param externalContext The external context to be attached to the LoggerContext
     * @return The LoggerContext.
     */
    public static LoggerContext initialize(final String name, final ClassLoader loader, final URI configLocation,
                                           final Object externalContext) {

        try {
            final Log4jContextFactory factory = getFactory();
            return factory == null ? null :
                    factory.getContext(FQCN, loader, externalContext, false, configLocation, name);
        } catch (final Exception ex) {
            LOGGER.error("There was a problem initializing the LoggerContext [{}] using configuration at [{}].",
                    name, configLocation, ex);
        }
        return null;
    }

    /**
     * Initializes the Logging Context.
     * @param name The Context name.
     * @param loader The ClassLoader for the Context (or null).
     * @param configLocation The configuration for the logging context (or null).
     * @param entry The external context entry to be attached to the LoggerContext
     * @return The LoggerContext.
     */
    public static LoggerContext initialize(final String name, final ClassLoader loader, final URI configLocation,
            final Map.Entry<String, Object> entry) {

        try {
            final Log4jContextFactory factory = getFactory();
            return factory == null ? null :
                    factory.getContext(FQCN, loader, entry, false, configLocation, name);
        } catch (final Exception ex) {
            LOGGER.error("There was a problem initializing the LoggerContext [{}] using configuration at [{}].",
                    name, configLocation, ex);
        }
        return null;
    }

    public static LoggerContext initialize(final String name, final ClassLoader loader, final List<URI> configLocations,
            final Object externalContext) {
        try {
            final Log4jContextFactory factory = getFactory();
            return factory == null ?
                    null :
                    factory.getContext(FQCN, loader, externalContext, false, configLocations, name);
        } catch (final Exception ex) {
            LOGGER.error("There was a problem initializing the LoggerContext [{}] using configurations at [{}].", name,
                    configLocations, ex);
        }
        return null;
    }

    /**
     * Initializes the Logging Context.
     * @param name The Context name.
     * @param configLocation The configuration for the logging context.
     * @return The LoggerContext or null if an error occurred (check the status logger).
     */
    public static LoggerContext initialize(final String name, final String configLocation) {
        return initialize(name, null, configLocation);
    }

    /**
     * Initializes the Logging Context.
     * @param configuration The Configuration.
     * @return The LoggerContext.
     */
    public static LoggerContext initialize(final Configuration configuration) {
        return initialize(null, configuration, null);
    }

    /**
     * Initializes the Logging Context.
     * @param loader The ClassLoader.
     * @param configuration The Configuration.
     * @return The LoggerContext.
     */
    public static LoggerContext initialize(final ClassLoader loader, final Configuration configuration) {
        return initialize(loader, configuration, null);
    }

    /**
     * Initializes the Logging Context.
     * @param loader The ClassLoader.
     * @param configuration The Configuration.
     * @param externalContext - The external context to be attached to the LoggerContext.
     * @return The LoggerContext.
     */
    public static LoggerContext initialize(final ClassLoader loader, final Configuration configuration, final Object externalContext) {
        try {
            final Log4jContextFactory factory = getFactory();
            return factory == null ? null :
                    factory.getContext(FQCN, loader, externalContext, false, configuration);
        } catch (final Exception ex) {
            LOGGER.error("There was a problem initializing the LoggerContext using configuration {}",
                    configuration.getName(), ex);
        }
        return null;
    }

    /**
     * Reconfigure using an already constructed Configuration.
     * @param configuration The configuration.
     * @since 2.13.0
     */
    public static void reconfigure(final Configuration configuration) {
        try {
            final Log4jContextFactory factory = getFactory();
            if (factory != null) {
                factory.getContext(FQCN, null, null, false)
                        .reconfigure(configuration);
            }
        } catch (final Exception ex) {
            LOGGER.error("There was a problem initializing the LoggerContext using configuration {}",
                    configuration.getName(), ex);
        }
    }

    /**
     * Reload the existing reconfiguration.
     * @since 2.12.0
     */
    public static void reconfigure() {
        try {
            Log4jContextFactory factory = getFactory();
            if (factory != null) {
                factory.getSelector().getContext(FQCN, null, false).reconfigure();
            } else {
                LOGGER.warn("Unable to reconfigure - Log4j has not been initialized.");
            }
        } catch (final Exception ex) {
            LOGGER.error("Error encountered trying to reconfigure logging", ex);
        }
    }

    /**
     * Reconfigure with a potentially new configuration.
     * @param uri The location of the configuration.
     * @since 2.12.0
     */
    public static void reconfigure(final URI uri) {
        try {
            Log4jContextFactory factory = getFactory();
            if (factory != null) {
                factory.getSelector().getContext(FQCN, null, false).setConfigLocation(uri);
            } else {
                LOGGER.warn("Unable to reconfigure - Log4j has not been initialized.");
            }
        } catch (final Exception ex) {
            LOGGER.error("Error encountered trying to reconfigure logging", ex);
        }
    }

    /**
     * Sets the levels of <code>parentLogger</code> and all 'child' loggers to the given <code>level</code>.
     * @param parentLogger the parent logger
     * @param level the new level
     */
    public static void setAllLevels(final String parentLogger, final Level level) {
        // 1) get logger config
        // 2) if exact match, use it, if not, create it.
        // 3) set level on logger config
        // 4) update child logger configs with level
        // 5) update loggers
        final LoggerContext loggerContext = LoggerContext.getContext(false);
        final Configuration config = loggerContext.getConfiguration();
        boolean set = setLevel(parentLogger, level, config);
        for (final Map.Entry<String, LoggerConfig> entry : config.getLoggers().entrySet()) {
            if (entry.getKey().startsWith(parentLogger)) {
                set |= setLevel(entry.getValue(), level);
            }
        }
        if (set) {
            loggerContext.updateLoggers();
        }
    }

    private static boolean setLevel(final LoggerConfig loggerConfig, final Level level) {
        final boolean set = !loggerConfig.getLevel().equals(level);
        if (set) {
            loggerConfig.setLevel(level);
        }
        return set;
    }

    /**
     * Sets logger levels.
     *
     * @param levelMap
     *            a levelMap where keys are level names and values are new
     *            Levels.
     */
    public static void setLevel(final Map<String, Level> levelMap) {
        final LoggerContext loggerContext = LoggerContext.getContext(false);
        final Configuration config = loggerContext.getConfiguration();
        boolean set = false;
        for (final Map.Entry<String, Level> entry : levelMap.entrySet()) {
            final String loggerName = entry.getKey();
            final Level level = entry.getValue();
            set |= setLevel(loggerName, level, config);
        }
        if (set) {
            loggerContext.updateLoggers();
        }
    }

    /**
     * Sets a logger's level.
     *
     * @param loggerName
     *            the logger name
     * @param level
     *            the new level
     */
    public static void setLevel(final String loggerName, final Level level) {
        final LoggerContext loggerContext = LoggerContext.getContext(false);
        if (Strings.isEmpty(loggerName)) {
            setRootLevel(level);
        } else if (setLevel(loggerName, level, loggerContext.getConfiguration())) {
            loggerContext.updateLoggers();
        }
    }

    private static boolean setLevel(final String loggerName, final Level level, final Configuration config) {
        boolean set;
        LoggerConfig loggerConfig = config.getLoggerConfig(loggerName);
        if (!loggerName.equals(loggerConfig.getName())) {
            // TODO Should additivity be inherited?
            loggerConfig = new LoggerConfig(loggerName, level, true);
            config.addLogger(loggerName, loggerConfig);
            loggerConfig.setLevel(level);
            set = true;
        } else {
            set = setLevel(loggerConfig, level);
        }
        return set;
    }

    /**
     * Sets the root logger's level.
     *
     * @param level
     *            the new level
     */
    public static void setRootLevel(final Level level) {
        final LoggerContext loggerContext = LoggerContext.getContext(false);
        final LoggerConfig loggerConfig = loggerContext.getConfiguration().getRootLogger();
        if (!loggerConfig.getLevel().equals(level)) {
            loggerConfig.setLevel(level);
            loggerContext.updateLoggers();
        }
    }

    /**
     * Shuts down the given logger context. This request does not wait for Log4j tasks to complete.
     * <p>
     * Log4j starts threads to perform certain actions like file rollovers; calling this method will not wait until the
     * rollover thread is done. When this method returns, these tasks' status are undefined, the tasks may be done or
     * not.
     * </p>
     *
     * @param ctx
     *            the logger context to shut down, may be null.
     */
    public static void shutdown(final LoggerContext ctx) {
        if (ctx != null) {
            ctx.stop();
        }
    }

    /**
     * Shuts down the given logger context.
     * <p>
     * Log4j can start threads to perform certain actions like file rollovers; calling this method with a positive
     * timeout will block until the rollover thread is done.
     * </p>
     *
     * @param ctx
     *            the logger context to shut down, may be null.
     * @param timeout
     *            the maximum time to wait
     * @param timeUnit
     *            the time unit of the timeout argument
     * @return {@code true} if the logger context terminated and {@code false} if the timeout elapsed before
     *         termination.
     *
     * @see LoggerContext#stop(long, TimeUnit)
     *
     * @since 2.7
     */
    public static boolean shutdown(final LoggerContext ctx, final long timeout, final TimeUnit timeUnit) {
        if (ctx != null) {
            return ctx.stop(timeout, timeUnit);
        }
        return true;
    }

    private Configurator() {
        // empty
    }
}

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

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