https://logging.apache.org/log4j/2.x/log4j-core/: The Apache Log4j Implementation (The Apache Software Foundation)
  • Ralph Goers (Nextiva)
  • Gary Gregory (Rocket Software)
  • Scott Deboy
  • Remko Popma
  • Nick Williams
  • Matt Sicker (CloudBees)
  • Bruce Brouwer
  • Mikael Ståldal (Spotify)
  • Carter Kozak 
/*
 * 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;

import static org.apache.logging.log4j.core.util.ShutdownCallbackRegistry.SHUTDOWN_HOOK_MARKER;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.File;
import java.net.URI;
import java.util.Collection;
import java.util.Objects;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.core.config.Configuration;
import org.apache.logging.log4j.core.config.ConfigurationFactory;
import org.apache.logging.log4j.core.config.ConfigurationListener;
import org.apache.logging.log4j.core.config.ConfigurationSource;
import org.apache.logging.log4j.core.config.DefaultConfiguration;
import org.apache.logging.log4j.core.config.NullConfiguration;
import org.apache.logging.log4j.core.config.Reconfigurable;
import org.apache.logging.log4j.core.impl.Log4jLogEvent;
import org.apache.logging.log4j.core.jmx.Server;
import org.apache.logging.log4j.core.util.Cancellable;
import org.apache.logging.log4j.core.util.ExecutorServices;
import org.apache.logging.log4j.core.util.Loader;
import org.apache.logging.log4j.core.util.NetUtils;
import org.apache.logging.log4j.core.util.ShutdownCallbackRegistry;
import org.apache.logging.log4j.message.MessageFactory;
import org.apache.logging.log4j.spi.AbstractLogger;
import org.apache.logging.log4j.spi.LoggerContextFactory;
import org.apache.logging.log4j.spi.LoggerRegistry;
import org.apache.logging.log4j.spi.Terminable;
import org.apache.logging.log4j.spi.ThreadContextMapFactory;
import org.apache.logging.log4j.util.PropertiesUtil;



The LoggerContext is the anchor for the logging system. It maintains a list of all the loggers requested by
applications and a reference to the Configuration. The Configuration will contain the configured loggers, appenders,
filters, etc and will be atomically updated whenever a reconfigure occurs.

/**
 * The LoggerContext is the anchor for the logging system. It maintains a list of all the loggers requested by
 * applications and a reference to the Configuration. The Configuration will contain the configured loggers, appenders,
 * filters, etc and will be atomically updated whenever a reconfigure occurs.
 */
public class LoggerContext extends AbstractLifeCycle
        implements org.apache.logging.log4j.spi.LoggerContext, AutoCloseable, Terminable, ConfigurationListener {

    static {
        try {
            // LOG4J2-1642 preload ExecutorServices as it is used in shutdown hook
            Loader.loadClass(ExecutorServices.class.getName());
        } catch (final Exception e) {
            LOGGER.error("Failed to preload ExecutorServices class.", e);
        }
    }

    
Property name of the property change event fired if the configuration is changed.

/**
     * Property name of the property change event fired if the configuration is changed.
     */
    public static final String PROPERTY_CONFIG = "config";

    private static final Configuration NULL_CONFIGURATION = new NullConfiguration();

    private final LoggerRegistry<Logger> loggerRegistry = new LoggerRegistry<>();
    private final CopyOnWriteArrayList<PropertyChangeListener> propertyChangeListeners = new CopyOnWriteArrayList<>();

    
The Configuration is volatile to guarantee that initialization of the Configuration has completed before the
reference is updated.

/**
     * The Configuration is volatile to guarantee that initialization of the Configuration has completed before the
     * reference is updated.
     */
    private volatile Configuration configuration = new DefaultConfiguration();
    private Object externalContext;
    private String contextName;
    private volatile URI configLocation;
    private Cancellable shutdownCallback;

    private final Lock configLock = new ReentrantLock();

    
Constructor taking only a name.

Params:
  • name – The context name.
/**
     * Constructor taking only a name.
     *
     * @param name The context name.
     */
    public LoggerContext(final String name) {
        this(name, null, (URI) null);
    }

    
Constructor taking a name and a reference to an external context.

Params:
  • name – The context name.
  • externalContext – The external context.
/**
     * Constructor taking a name and a reference to an external context.
     *
     * @param name The context name.
     * @param externalContext The external context.
     */
    public LoggerContext(final String name, final Object externalContext) {
        this(name, externalContext, (URI) null);
    }

    
Constructor taking a name, external context and a configuration URI.

Params:
  • name – The context name.
  • externalContext – The external context.
  • configLocn – The location of the configuration as a URI.
/**
     * Constructor taking a name, external context and a configuration URI.
     *
     * @param name The context name.
     * @param externalContext The external context.
     * @param configLocn The location of the configuration as a URI.
     */
    public LoggerContext(final String name, final Object externalContext, final URI configLocn) {
        this.contextName = name;
        this.externalContext = externalContext;
        this.configLocation = configLocn;
    }

    
Constructor taking a name external context and a configuration location String. The location must be resolvable
to a File.

Params:
  • name – The configuration location.
  • externalContext – The external context.
  • configLocn – The configuration location.
/**
     * Constructor taking a name external context and a configuration location String. The location must be resolvable
     * to a File.
     *
     * @param name The configuration location.
     * @param externalContext The external context.
     * @param configLocn The configuration location.
     */
    public LoggerContext(final String name, final Object externalContext, final String configLocn) {
        this.contextName = name;
        this.externalContext = externalContext;
        if (configLocn != null) {
            URI uri;
            try {
                uri = new File(configLocn).toURI();
            } catch (final Exception ex) {
                uri = null;
            }
            configLocation = uri;
        } else {
            configLocation = null;
        }
    }

    
Returns the current LoggerContext.


Avoids the type cast for:



(LoggerContext) LogManager.getContext();




WARNING - The LoggerContext returned by this method may not be the LoggerContext used to create a Logger for the
calling class.



See Also:
Returns:The current LoggerContext.
/**
     * Returns the current LoggerContext.
     * <p>
     * Avoids the type cast for:
     * </p>
     *
     * <pre>
     * (LoggerContext) LogManager.getContext();
     * </pre>
     *
     * <p>
     * WARNING - The LoggerContext returned by this method may not be the LoggerContext used to create a Logger for the
     * calling class.
     * </p>
     *
     * @return The current LoggerContext.
     * @see LogManager#getContext()
     */
    public static LoggerContext getContext() {
        return (LoggerContext) LogManager.getContext();
    }

    
Returns a LoggerContext.


Avoids the type cast for:



(LoggerContext) LogManager.getContext(currentContext);



Params:
  • currentContext – if false the LoggerContext appropriate for the caller of this method is returned. For
           example, in a web application if the caller is a class in WEB-INF/lib then one LoggerContext may be
           returned and if the caller is a class in the container's classpath then a different LoggerContext may
           be returned. If true then only a single LoggerContext will be returned.
See Also:
Returns:a LoggerContext.
/**
     * Returns a LoggerContext.
     * <p>
     * Avoids the type cast for:
     * </p>
     *
     * <pre>
     * (LoggerContext) LogManager.getContext(currentContext);
     * </pre>
     *
     * @param currentContext if false the LoggerContext appropriate for the caller of this method is returned. For
     *            example, in a web application if the caller is a class in WEB-INF/lib then one LoggerContext may be
     *            returned and if the caller is a class in the container's classpath then a different LoggerContext may
     *            be returned. If true then only a single LoggerContext will be returned.
     * @return a LoggerContext.
     * @see LogManager#getContext(boolean)
     */
    public static LoggerContext getContext(final boolean currentContext) {
        return (LoggerContext) LogManager.getContext(currentContext);
    }

    
Returns a LoggerContext.


Avoids the type cast for:



(LoggerContext) LogManager.getContext(loader, currentContext, configLocation);



Params:
  • loader – The ClassLoader for the context. If null the context will attempt to determine the appropriate
           ClassLoader.
  • currentContext – if false the LoggerContext appropriate for the caller of this method is returned. For
           example, in a web application if the caller is a class in WEB-INF/lib then one LoggerContext may be
           returned and if the caller is a class in the container's classpath then a different LoggerContext may
           be returned. If true then only a single LoggerContext will be returned.
  • configLocation – The URI for the configuration to use.
See Also:
Returns:a LoggerContext.
/**
     * Returns a LoggerContext.
     * <p>
     * Avoids the type cast for:
     * </p>
     *
     * <pre>
     * (LoggerContext) LogManager.getContext(loader, currentContext, configLocation);
     * </pre>
     *
     * @param loader The ClassLoader for the context. If null the context will attempt to determine the appropriate
     *            ClassLoader.
     * @param currentContext if false the LoggerContext appropriate for the caller of this method is returned. For
     *            example, in a web application if the caller is a class in WEB-INF/lib then one LoggerContext may be
     *            returned and if the caller is a class in the container's classpath then a different LoggerContext may
     *            be returned. If true then only a single LoggerContext will be returned.
     * @param configLocation The URI for the configuration to use.
     * @return a LoggerContext.
     * @see LogManager#getContext(ClassLoader, boolean, URI)
     */
    public static LoggerContext getContext(final ClassLoader loader, final boolean currentContext,
            final URI configLocation) {
        return (LoggerContext) LogManager.getContext(loader, currentContext, configLocation);
    }

    @Override
    public void start() {
        LOGGER.debug("Starting LoggerContext[name={}, {}]...", getName(), this);
        if (PropertiesUtil.getProperties().getBooleanProperty("log4j.LoggerContext.stacktrace.on.start", false)) {
            LOGGER.debug("Stack trace to locate invoker",
                    new Exception("Not a real error, showing stack trace to locate invoker"));
        }
        if (configLock.tryLock()) {
            try {
                if (this.isInitialized() || this.isStopped()) {
                    this.setStarting();
                    reconfigure();
                    if (this.configuration.isShutdownHookEnabled()) {
                        setUpShutdownHook();
                    }
                    this.setStarted();
                }
            } finally {
                configLock.unlock();
            }
        }
        LOGGER.debug("LoggerContext[name={}, {}] started OK.", getName(), this);
    }

    
Starts with a specific configuration.

Params:
  • config – The new Configuration.
/**
     * Starts with a specific configuration.
     *
     * @param config The new Configuration.
     */
    public void start(final Configuration config) {
        LOGGER.debug("Starting LoggerContext[name={}, {}] with configuration {}...", getName(), this, config);
        if (configLock.tryLock()) {
            try {
                if (this.isInitialized() || this.isStopped()) {
                    if (this.configuration.isShutdownHookEnabled()) {
                        setUpShutdownHook();
                    }
                    this.setStarted();
                }
            } finally {
                configLock.unlock();
            }
        }
        setConfiguration(config);
        LOGGER.debug("LoggerContext[name={}, {}] started OK with configuration {}.", getName(), this, config);
    }

    private void setUpShutdownHook() {
        if (shutdownCallback == null) {
            final LoggerContextFactory factory = LogManager.getFactory();
            if (factory instanceof ShutdownCallbackRegistry) {
                LOGGER.debug(SHUTDOWN_HOOK_MARKER, "Shutdown hook enabled. Registering a new one.");
                try {
                    final long shutdownTimeoutMillis = this.configuration.getShutdownTimeoutMillis();
                    this.shutdownCallback = ((ShutdownCallbackRegistry) factory).addShutdownCallback(new Runnable() {
                        @Override
                        public void run() {
                            @SuppressWarnings("resource")
                            final LoggerContext context = LoggerContext.this;
                            LOGGER.debug(SHUTDOWN_HOOK_MARKER, "Stopping LoggerContext[name={}, {}]",
                                    context.getName(), context);
                            context.stop(shutdownTimeoutMillis, TimeUnit.MILLISECONDS);
                        }

                        @Override
                        public String toString() {
                            return "Shutdown callback for LoggerContext[name=" + LoggerContext.this.getName() + ']';
                        }
                    });
                } catch (final IllegalStateException e) {
                    throw new IllegalStateException(
                            "Unable to register Log4j shutdown hook because JVM is shutting down.", e);
                } catch (final SecurityException e) {
                    LOGGER.error(SHUTDOWN_HOOK_MARKER, "Unable to register shutdown hook due to security restrictions",
                            e);
                }
            }
        }
    }

    @Override
    public void close() {
        stop();
    }

    @Override
    public void terminate() {
        stop();
    }

    
Blocks until all Log4j tasks have completed execution after a shutdown request and all appenders have shut down,
or the timeout occurs, or the current thread is interrupted, whichever happens first.


Not all appenders will honor this, it is a hint and not an absolute guarantee that the this method not block longer.
Setting timeout too low increase the risk of losing outstanding log events not yet written to the final
destination.


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.

Params:
  • timeout – the maximum time to wait, or 0 which mean that each apppender uses its default timeout, and don't wait for background
tasks
  • timeUnit – 
           the time unit of the timeout argument
Returns:true if the logger context terminated and false if the timeout elapsed before termination.
Since:2.7
/**
     * Blocks until all Log4j tasks have completed execution after a shutdown request and all appenders have shut down,
     * or the timeout occurs, or the current thread is interrupted, whichever happens first.
     * <p>
     * Not all appenders will honor this, it is a hint and not an absolute guarantee that the this method not block longer.
     * Setting timeout too low increase the risk of losing outstanding log events not yet written to the final
     * destination.
     * <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.
     *
     * @param timeout the maximum time to wait, or 0 which mean that each apppender uses its default timeout, and don't wait for background
    tasks
     * @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.
     * @since 2.7
     */
    @Override
    public boolean stop(final long timeout, final TimeUnit timeUnit) {
        LOGGER.debug("Stopping LoggerContext[name={}, {}]...", getName(), this);
        configLock.lock();
        try {
            if (this.isStopped()) {
                return true;
            }

            this.setStopping();
            try {
                Server.unregisterLoggerContext(getName()); // LOG4J2-406, LOG4J2-500
            } catch (final LinkageError | Exception e) {
                // LOG4J2-1506 Hello Android, GAE
                LOGGER.error("Unable to unregister MBeans", e);
            }
            if (shutdownCallback != null) {
                shutdownCallback.cancel();
                shutdownCallback = null;
            }
            final Configuration prev = configuration;
            configuration = NULL_CONFIGURATION;
            updateLoggers();
            if (prev instanceof LifeCycle2) {
                ((LifeCycle2) prev).stop(timeout, timeUnit);
            } else {
                prev.stop();
            }
            externalContext = null;
            LogManager.getFactory().removeContext(this);
        } finally {
            configLock.unlock();
            this.setStopped();
        }
        LOGGER.debug("Stopped LoggerContext[name={}, {}] with status {}", getName(), this, true);
        return true;
    }

    
Gets the name.

Returns:the name.
/**
     * Gets the name.
     *
     * @return the name.
     */
    public String getName() {
        return contextName;
    }

    
Gets the root logger.

Returns:the root logger.
/**
     * Gets the root logger.
     *
     * @return the root logger.
     */
    public Logger getRootLogger() {
        return getLogger(LogManager.ROOT_LOGGER_NAME);
    }

    
Sets the name.

Params:
  • name – the new LoggerContext name
Throws:
/**
     * Sets the name.
     *
     * @param name the new LoggerContext name
     * @throws NullPointerException if the specified name is {@code null}
     */
    public void setName(final String name) {
    	contextName = Objects.requireNonNull(name);
    }

    
Sets the external context.

Params:
  • context – The external context.
/**
     * Sets the external context.
     *
     * @param context The external context.
     */
    public void setExternalContext(final Object context) {
        this.externalContext = context;
    }

    
Returns the external context.

Returns:The external context.
/**
     * Returns the external context.
     *
     * @return The external context.
     */
    @Override
    public Object getExternalContext() {
        return this.externalContext;
    }

    
Gets a Logger from the Context.

Params:
  • name – The name of the Logger to return.
Returns:The Logger.
/**
     * Gets a Logger from the Context.
     *
     * @param name The name of the Logger to return.
     * @return The Logger.
     */
    @Override
    public Logger getLogger(final String name) {
        return getLogger(name, null);
    }

    
Gets a collection of the current loggers.


Whether this collection is a copy of the underlying collection or not is undefined. Therefore, modify this
collection at your own risk.



Returns:a collection of the current loggers.
/**
     * Gets a collection of the current loggers.
     * <p>
     * Whether this collection is a copy of the underlying collection or not is undefined. Therefore, modify this
     * collection at your own risk.
     * </p>
     *
     * @return a collection of the current loggers.
     */
    public Collection<Logger> getLoggers() {
        return loggerRegistry.getLoggers();
    }

    
Obtains a Logger from the Context.

Params:
  • name – The name of the Logger to return.
  • messageFactory – The message factory is used only when creating a logger, subsequent use does not change the
           logger but will log a warning if mismatched.
Returns:The Logger.
/**
     * Obtains a Logger from the Context.
     *
     * @param name The name of the Logger to return.
     * @param messageFactory The message factory is used only when creating a logger, subsequent use does not change the
     *            logger but will log a warning if mismatched.
     * @return The Logger.
     */
    @Override
    public Logger getLogger(final String name, final MessageFactory messageFactory) {
        // Note: This is the only method where we add entries to the 'loggerRegistry' ivar.
        Logger logger = loggerRegistry.getLogger(name, messageFactory);
        if (logger != null) {
            AbstractLogger.checkMessageFactory(logger, messageFactory);
            return logger;
        }

        logger = newInstance(this, name, messageFactory);
        loggerRegistry.putIfAbsent(name, messageFactory, logger);
        return loggerRegistry.getLogger(name, messageFactory);
    }

    
Determines if the specified Logger exists.

Params:
  • name – The Logger name to search for.
Returns:True if the Logger exists, false otherwise.
/**
     * Determines if the specified Logger exists.
     *
     * @param name The Logger name to search for.
     * @return True if the Logger exists, false otherwise.
     */
    @Override
    public boolean hasLogger(final String name) {
        return loggerRegistry.hasLogger(name);
    }

    
Determines if the specified Logger exists.

Params:
  • name – The Logger name to search for.
Returns:True if the Logger exists, false otherwise.
/**
     * Determines if the specified Logger exists.
     *
     * @param name The Logger name to search for.
     * @return True if the Logger exists, false otherwise.
     */
    @Override
    public boolean hasLogger(final String name, final MessageFactory messageFactory) {
        return loggerRegistry.hasLogger(name, messageFactory);
    }

    
Determines if the specified Logger exists.

Params:
  • name – The Logger name to search for.
Returns:True if the Logger exists, false otherwise.
/**
     * Determines if the specified Logger exists.
     *
     * @param name The Logger name to search for.
     * @return True if the Logger exists, false otherwise.
     */
    @Override
    public boolean hasLogger(final String name, final Class<? extends MessageFactory> messageFactoryClass) {
        return loggerRegistry.hasLogger(name, messageFactoryClass);
    }

	
Returns the current Configuration. The Configuration will be replaced when a reconfigure occurs.

Returns:The current Configuration, never null, but may be NullConfiguration.
/**
	 * Returns the current Configuration. The Configuration will be replaced when a reconfigure occurs.
	 *
	 * @return The current Configuration, never {@code null}, but may be
	 * {@link org.apache.logging.log4j.core.config.NullConfiguration}.
	 */
	public Configuration getConfiguration() {
		return configuration;
	}

    
Adds a Filter to the Configuration. Filters that are added through the API will be lost when a reconfigure
occurs.

Params:
  • filter – The Filter to add.
/**
     * Adds a Filter to the Configuration. Filters that are added through the API will be lost when a reconfigure
     * occurs.
     *
     * @param filter The Filter to add.
     */
    public void addFilter(final Filter filter) {
        configuration.addFilter(filter);
    }

    
Removes a Filter from the current Configuration.

Params:
  • filter – The Filter to remove.
/**
     * Removes a Filter from the current Configuration.
     *
     * @param filter The Filter to remove.
     */
    public void removeFilter(final Filter filter) {
        configuration.removeFilter(filter);
    }

    
Sets the Configuration to be used.

Params:
  • config – The new Configuration.
Returns:The previous Configuration.
/**
     * Sets the Configuration to be used.
     *
     * @param config The new Configuration.
     * @return The previous Configuration.
     */
    public Configuration setConfiguration(final Configuration config) {
        if (config == null) {
            LOGGER.error("No configuration found for context '{}'.", contextName);
            // No change, return the current configuration.
            return this.configuration;
        }
        configLock.lock();
        try {
            final Configuration prev = this.configuration;
            config.addListener(this);

            final ConcurrentMap<String, String> map = config.getComponent(Configuration.CONTEXT_PROPERTIES);

            try { // LOG4J2-719 network access may throw android.os.NetworkOnMainThreadException
                map.putIfAbsent("hostName", NetUtils.getLocalHostname());
            } catch (final Exception ex) {
                LOGGER.debug("Ignoring {}, setting hostName to 'unknown'", ex.toString());
                map.putIfAbsent("hostName", "unknown");
            }
            map.putIfAbsent("contextName", contextName);
            config.start();
            this.configuration = config;
            updateLoggers();
            if (prev != null) {
                prev.removeListener(this);
                prev.stop();
            }

            firePropertyChangeEvent(new PropertyChangeEvent(this, PROPERTY_CONFIG, prev, config));

            try {
                Server.reregisterMBeansAfterReconfigure();
            } catch (final LinkageError | Exception e) {
                // LOG4J2-716: Android has no java.lang.management
                LOGGER.error("Could not reconfigure JMX", e);
            }
            // AsyncLoggers update their nanoClock when the configuration changes
            Log4jLogEvent.setNanoClock(configuration.getNanoClock());

            return prev;
        } finally {
            configLock.unlock();
        }
    }

    private void firePropertyChangeEvent(final PropertyChangeEvent event) {
        for (final PropertyChangeListener listener : propertyChangeListeners) {
            listener.propertyChange(event);
        }
    }

    public void addPropertyChangeListener(final PropertyChangeListener listener) {
        propertyChangeListeners.add(Objects.requireNonNull(listener, "listener"));
    }

    public void removePropertyChangeListener(final PropertyChangeListener listener) {
        propertyChangeListeners.remove(listener);
    }

    
Returns the initial configuration location or null. The returned value may not be the location of the current configuration. Use getConfiguration().
getConfigurationSource().getLocation() to get the actual source of the current configuration. 
Returns:the initial configuration location or null
/**
     * Returns the initial configuration location or {@code null}. The returned value may not be the location of the
     * current configuration. Use {@link #getConfiguration()}.{@link Configuration#getConfigurationSource()
     * getConfigurationSource()}.{@link ConfigurationSource#getLocation() getLocation()} to get the actual source of the
     * current configuration.
     *
     * @return the initial configuration location or {@code null}
     */
    public URI getConfigLocation() {
        return configLocation;
    }

    
Sets the configLocation to the specified value and reconfigures this context.

Params:
  • configLocation – the location of the new configuration
/**
     * Sets the configLocation to the specified value and reconfigures this context.
     *
     * @param configLocation the location of the new configuration
     */
    public void setConfigLocation(final URI configLocation) {
        this.configLocation = configLocation;
        reconfigure(configLocation);
    }

    
Reconfigures the context.

/**
     * Reconfigures the context.
     */
    private void reconfigure(final URI configURI) {
        final ClassLoader cl = ClassLoader.class.isInstance(externalContext) ? (ClassLoader) externalContext : null;
        LOGGER.debug("Reconfiguration started for context[name={}] at URI {} ({}) with optional ClassLoader: {}",
                contextName, configURI, this, cl);
        final Configuration instance = ConfigurationFactory.getInstance().getConfiguration(this, contextName, configURI, cl);
        if (instance == null) {
            LOGGER.error("Reconfiguration failed: No configuration found for '{}' at '{}' in '{}'", contextName, configURI, cl);
        } else {
            setConfiguration(instance);
            /*
             * instance.start(); Configuration old = setConfiguration(instance); updateLoggers(); if (old != null) {
             * old.stop(); }
             */
            final String location = configuration == null ? "?" : String.valueOf(configuration.getConfigurationSource());
            LOGGER.debug("Reconfiguration complete for context[name={}] at URI {} ({}) with optional ClassLoader: {}",
                    contextName, location, this, cl);
        }
    }

    
Reconfigures the context. Log4j does not remove Loggers during a reconfiguration. Log4j will create new
LoggerConfig objects and Log4j will point the Loggers at the new LoggerConfigs. Log4j will free the old
LoggerConfig, along with old Appenders and Filters.

/**
     * Reconfigures the context. Log4j does not remove Loggers during a reconfiguration. Log4j will create new
     * LoggerConfig objects and Log4j will point the Loggers at the new LoggerConfigs. Log4j will free the old
     * LoggerConfig, along with old Appenders and Filters.
     */
    public void reconfigure() {
        reconfigure(configLocation);
    }

    
Causes all Loggers to be updated against the current Configuration.

/**
     * Causes all Loggers to be updated against the current Configuration.
     */
    public void updateLoggers() {
        updateLoggers(this.configuration);
    }

    
Causes all Logger to be updated against the specified Configuration.

Params:
  • config – The Configuration.
/**
     * Causes all Logger to be updated against the specified Configuration.
     *
     * @param config The Configuration.
     */
    public void updateLoggers(final Configuration config) {
        final Configuration old = this.configuration;
        for (final Logger logger : loggerRegistry.getLoggers()) {
            logger.updateConfiguration(config);
        }
        firePropertyChangeEvent(new PropertyChangeEvent(this, PROPERTY_CONFIG, old, config));
    }

    
Causes a reconfiguration to take place when the underlying configuration file changes.

Params:
  • reconfigurable – The Configuration that can be reconfigured.
/**
     * Causes a reconfiguration to take place when the underlying configuration file changes.
     *
     * @param reconfigurable The Configuration that can be reconfigured.
     */
    @Override
	public synchronized void onChange(final Reconfigurable reconfigurable) {
		final long startMillis = System.currentTimeMillis();
		LOGGER.debug("Reconfiguration started for context {} ({})", contextName, this);
		initApiModule();
		final Configuration newConfig = reconfigurable.reconfigure();
		if (newConfig != null) {
			setConfiguration(newConfig);
			LOGGER.debug("Reconfiguration completed for {} ({}) in {} milliseconds.", contextName, this,
					System.currentTimeMillis() - startMillis);
		} else {
			LOGGER.debug("Reconfiguration failed for {} ({}) in {} milliseconds.", contextName, this,
					System.currentTimeMillis() - startMillis);
		}
	}

    private void initApiModule() {
        ThreadContextMapFactory.init(); // Or make public and call ThreadContext.init() which calls ThreadContextMapFactory.init().
    }

    // LOG4J2-151: changed visibility from private to protected
    protected Logger newInstance(final LoggerContext ctx, final String name, final MessageFactory messageFactory) {
        return new Logger(ctx, name, messageFactory);
    }

}