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/jmx/LoggerContextAdmin.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.jmx;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.Map;
import java.util.Objects;
import java.util.concurrent.Executor;
import java.util.concurrent.atomic.AtomicLong;

import javax.management.MBeanNotificationInfo;
import javax.management.Notification;
import javax.management.NotificationBroadcasterSupport;
import javax.management.ObjectName;

import org.apache.logging.log4j.core.LoggerContext;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.ConfigurationFactory;
import org.apache.logging.log4j.core.config.ConfigurationSource;
import org.apache.logging.log4j.core.util.Closer;
import org.apache.logging.log4j.status.StatusLogger;
import org.apache.logging.log4j.util.Strings;

/**
 * Implementation of the {@code LoggerContextAdminMBean} interface.
 */
public class LoggerContextAdmin extends NotificationBroadcasterSupport implements LoggerContextAdminMBean,
        PropertyChangeListener {
    private static final int PAGE = 4 * 1024;
    private static final int TEXT_BUFFER = 64 * 1024;
    private static final int BUFFER_SIZE = 2048;
    private static final StatusLogger LOGGER = StatusLogger.getLogger();

    private final AtomicLong sequenceNo = new AtomicLong();
    private final ObjectName objectName;
    private final LoggerContext loggerContext;

    /**
     * Constructs a new {@code LoggerContextAdmin} with the {@code Executor} to be used for sending {@code Notification}
     * s asynchronously to listeners.
     *
     * @param executor used to send notifications asynchronously
     * @param loggerContext the instrumented object
     */
    public LoggerContextAdmin(final LoggerContext loggerContext, final Executor executor) {
        super(executor, createNotificationInfo());
        this.loggerContext = Objects.requireNonNull(loggerContext, "loggerContext");
        try {
            final String ctxName = Server.escape(loggerContext.getName());
            final String name = String.format(PATTERN, ctxName);
            objectName = new ObjectName(name);
        } catch (final Exception e) {
            throw new IllegalStateException(e);
        }
        loggerContext.addPropertyChangeListener(this);
    }

    private static MBeanNotificationInfo createNotificationInfo() {
        final String[] notifTypes = new String[] { NOTIF_TYPE_RECONFIGURED };
        final String name = Notification.class.getName();
        final String description = "Configuration reconfigured";
        return new MBeanNotificationInfo(notifTypes, name, description);
    }

    @Override
    public String getStatus() {
        return loggerContext.getState().toString();
    }

    @Override
    public String getName() {
        return loggerContext.getName();
    }

    private Configuration getConfig() {
        return loggerContext.getConfiguration();
    }

    @Override
    public String getConfigLocationUri() {
        if (loggerContext.getConfigLocation() != null) {
            return String.valueOf(loggerContext.getConfigLocation());
        }
        if (getConfigName() != null) {
            return String.valueOf(new File(getConfigName()).toURI());
        }
        return Strings.EMPTY;
    }

    @Override
    public void setConfigLocationUri(final String configLocation) throws URISyntaxException, IOException {
        if (configLocation == null || configLocation.isEmpty()) {
            throw new IllegalArgumentException("Missing configuration location");
        }
        LOGGER.debug("---------");
        LOGGER.debug("Remote request to reconfigure using location " + configLocation);
        final File configFile = new File(configLocation);
        ConfigurationSource configSource = null;
        if (configFile.exists()) {
            LOGGER.debug("Opening config file {}", configFile.getAbsolutePath());
            configSource = new ConfigurationSource(new FileInputStream(configFile), configFile);
        } else {
            final URL configURL = new URL(configLocation);
            LOGGER.debug("Opening config URL {}", configURL);
            configSource = new ConfigurationSource(configURL.openStream(), configURL);
        }
        final Configuration config = ConfigurationFactory.getInstance().getConfiguration(loggerContext, configSource);
        loggerContext.start(config);
        LOGGER.debug("Completed remote request to reconfigure.");
    }

    @Override
    public void propertyChange(final PropertyChangeEvent evt) {
        if (!LoggerContext.PROPERTY_CONFIG.equals(evt.getPropertyName())) {
            return;
        }
        final Notification notif = new Notification(NOTIF_TYPE_RECONFIGURED, getObjectName(), nextSeqNo(), now(), null);
        sendNotification(notif);
    }

    @Override
    public String getConfigText() throws IOException {
        return getConfigText(StandardCharsets.UTF_8.name());
    }

    @Override
    public String getConfigText(final String charsetName) throws IOException {
        try {
            final ConfigurationSource source = loggerContext.getConfiguration().getConfigurationSource();
            final ConfigurationSource copy = source.resetInputStream();
            final Charset charset = Charset.forName(charsetName);
            return readContents(copy.getInputStream(), charset);
        } catch (final Exception ex) {
            final StringWriter sw = new StringWriter(BUFFER_SIZE);
            ex.printStackTrace(new PrintWriter(sw));
            return sw.toString();
        }
    }

    /**
     * Returns the contents of the specified input stream as a String.
     * @param in stream to read from
     * @param charset MUST not be null
     * @return stream contents
     * @throws IOException if a problem occurred reading from the stream.
     */
    private String readContents(final InputStream in, final Charset charset) throws IOException {
        Reader reader = null;
        try {
            reader = new InputStreamReader(in, charset);
            final StringBuilder result = new StringBuilder(TEXT_BUFFER);
            final char[] buff = new char[PAGE];
            int count = -1;
            while ((count = reader.read(buff)) >= 0) {
                result.append(buff, 0, count);
            }
            return result.toString();
        } finally {
            Closer.closeSilently(in);
            Closer.closeSilently(reader);
        }
    }

    @Override
    public void setConfigText(final String configText, final String charsetName) {
        LOGGER.debug("---------");
        LOGGER.debug("Remote request to reconfigure from config text.");

        try {
            final InputStream in = new ByteArrayInputStream(configText.getBytes(charsetName));
            final ConfigurationSource source = new ConfigurationSource(in);
            final Configuration updated = ConfigurationFactory.getInstance().getConfiguration(loggerContext, source);
            loggerContext.start(updated);
            LOGGER.debug("Completed remote request to reconfigure from config text.");
        } catch (final Exception ex) {
            final String msg = "Could not reconfigure from config text";
            LOGGER.error(msg, ex);
            throw new IllegalArgumentException(msg, ex);
        }
    }

    @Override
    public String getConfigName() {
        return getConfig().getName();
    }

    @Override
    public String getConfigClassName() {
        return getConfig().getClass().getName();
    }

    @Override
    public String getConfigFilter() {
        return String.valueOf(getConfig().getFilter());
    }

    @Override
    public Map<String, String> getConfigProperties() {
        return getConfig().getProperties();
    }

    /**
     * Returns the {@code ObjectName} of this mbean.
     *
     * @return the {@code ObjectName}
     * @see LoggerContextAdminMBean#PATTERN
     */
    @Override
    public ObjectName getObjectName() {
        return objectName;
    }

    private long nextSeqNo() {
        return sequenceNo.getAndIncrement();
    }

    private long now() {
        return System.currentTimeMillis();
    }
}

⏎ org/apache/logging/log4j/core/jmx/LoggerContextAdmin.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
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