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/Node.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 java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.logging.log4j.core.config.plugins.util.PluginType;

/**
 * A Configuration node.
 */
public class Node {

    /**
     * Main plugin category for plugins which are represented as a configuration node. Such plugins tend to be
     * available as XML elements in a configuration file.
     *
     * @since 2.1
     */
    public static final String CATEGORY = "Core";

    private final Node parent;
    private final String name;
    private String value;
    private final PluginType<?> type;
    private final Map<String, String> attributes = new HashMap<>();
    private final List<Node> children = new ArrayList<>();
    private Object object;


    /**
     * Creates a new instance of {@code Node} and initializes it
     * with a name and the corresponding XML element.
     *
     * @param parent the node's parent.
     * @param name the node's name.
     * @param type The Plugin Type associated with the node.
     */
    public Node(final Node parent, final String name, final PluginType<?> type) {
        this.parent = parent;
        this.name = name;
        this.type = type;
    }

    public Node() {
        this.parent = null;
        this.name = null;
        this.type = null;
    }

    public Node(final Node node) {
        this.parent = node.parent;
        this.name = node.name;
        this.type = node.type;
        this.attributes.putAll(node.getAttributes());
        this.value = node.getValue();
        for (final Node child : node.getChildren()) {
            this.children.add(new Node(child));
        }
        this.object = node.object;
    }

    public Map<String, String> getAttributes() {
        return attributes;
    }

    public List<Node> getChildren() {
        return children;
    }

    public boolean hasChildren() {
        return !children.isEmpty();
    }

    public String getValue() {
        return value;
    }

    public void setValue(final String value) {
        this.value = value;
    }

    public Node getParent() {
        return parent;
    }

    public String getName() {
        return name;
    }

    public boolean isRoot() {
        return parent == null;
    }

    public void setObject(final Object obj) {
        object = obj;
    }

    @SuppressWarnings("unchecked")
    public <T> T getObject() {
        return (T) object;
    }

    /**
     * Returns this node's object cast to the given class.
     *
     * @param clazz the class to cast this node's object to.
     * @param <T>   the type to cast to.
     * @return this node's object.
     * @since 2.1
     */
    public <T> T getObject(final Class<T> clazz) {
        return clazz.cast(object);
    }

    /**
     * Determines if this node's object is an instance of the given class.
     *
     * @param clazz the class to check.
     * @return {@code true} if this node's object is an instance of the given class.
     * @since 2.1
     */
    public boolean isInstanceOf(final Class<?> clazz) {
        return clazz.isInstance(object);
    }

    public PluginType<?> getType() {
        return type;
    }

    @Override
    public String toString() {
        if (object == null) {
            return "null";
        }
        return type.isObjectPrintable() ? object.toString() :
            type.getPluginClass().getName() + " with name " + name;
    }
}

⏎ org/apache/logging/log4j/core/config/Node.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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