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/selector/ContextSelector.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.selector;

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

import org.apache.logging.log4j.core.LoggerContext;

/**
 * Interface used to locate a LoggerContext.
 */
public interface ContextSelector {

    long DEFAULT_STOP_TIMEOUT = 50;

    /**
     * Shuts down the LoggerContext.
     * @param fqcn The fully qualified class name of the caller.
     * @param loader The ClassLoader to use or null.
     * @param currentContext If true returns the current Context, if false returns the Context appropriate
     * @param allContexts if true all LoggerContexts that can be located will be shutdown.
     * @since 2.13.0
     */
    default void shutdown(final String fqcn, final ClassLoader loader, final boolean currentContext,
                          final boolean allContexts) {
        if (hasContext(fqcn, loader, currentContext)) {
            getContext(fqcn, loader, currentContext).stop(DEFAULT_STOP_TIMEOUT, TimeUnit.MILLISECONDS);
        }
    }

    /**
     * Checks to see if a LoggerContext is installed. The default implementation returns false.
     * @param fqcn The fully qualified class name of the caller.
     * @param loader The ClassLoader to use or null.
     * @param currentContext If true returns the current Context, if false returns the Context appropriate
     * for the caller if a more appropriate Context can be determined.
     * @return true if a LoggerContext has been installed, false otherwise.
     * @since 2.13.0
     */
    default boolean hasContext(String fqcn, ClassLoader loader, boolean currentContext) {
        return false;
    }

    /**
     * Returns the LoggerContext.
     * @param fqcn The fully qualified class name of the caller.
     * @param loader ClassLoader to use or null.
     * @param currentContext If true returns the current Context, if false returns the Context appropriate
     * for the caller if a more appropriate Context can be determined.
     * @return The LoggerContext.
     */
    LoggerContext getContext(String fqcn, ClassLoader loader, boolean currentContext);

    /**
     * Returns the LoggerContext.
     * @param fqcn The fully qualified class name of the caller.
     * @param loader ClassLoader to use or null.
     * @param entry An entry for the external Context map.
     * @param currentContext If true returns the current Context, if false returns the Context appropriate
     * for the caller if a more appropriate Context can be determined.
     * @return The LoggerContext.
     */
    default LoggerContext getContext(String fqcn, ClassLoader loader, Map.Entry<String, Object> entry, boolean currentContext) {
        LoggerContext lc = getContext(fqcn, loader, currentContext);
        if (lc != null) {
            lc.putObject(entry.getKey(), entry.getValue());
        }
        return lc;
    }

    /**
     * Returns the LoggerContext.
     * @param fqcn The fully qualified class name of the caller.
     * @param loader ClassLoader to use or null.
     * @param currentContext If true returns the current Context, if false returns the Context appropriate
     * for the caller if a more appropriate Context can be determined.
     * @param configLocation The location of the configuration for the LoggerContext.
     * @return The LoggerContext.
     */
    LoggerContext getContext(String fqcn, ClassLoader loader, boolean currentContext, URI configLocation);

    /**
     * Returns the LoggerContext.
     * @param fqcn The fully qualified class name of the caller.
     * @param loader ClassLoader to use or null.
     * @param currentContext If true returns the current Context, if false returns the Context appropriate
     * for the caller if a more appropriate Context can be determined.
     * @param configLocation The location of the configuration for the LoggerContext.
     * @return The LoggerContext.
     */
    default LoggerContext getContext(String fqcn, ClassLoader loader, Map.Entry<String, Object> entry,
            boolean currentContext, URI configLocation) {
        LoggerContext lc = getContext(fqcn, loader, currentContext, configLocation);
        if (lc != null) {
            lc.putObject(entry.getKey(), entry.getValue());
        }
        return lc;
    }

    /**
     * Returns a List of all the available LoggerContexts.
     * @return The List of LoggerContexts.
     */
    List<LoggerContext> getLoggerContexts();

    /**
     * Remove any references to the LoggerContext.
     * @param context The context to remove.
     */
    void removeContext(LoggerContext context);


}

⏎ org/apache/logging/log4j/core/selector/ContextSelector.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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