Apache Log4j API provides the interface that applications should code to and provides the adapter components required for implementers to create a logging implementation. Apache Log4j API is a required module to use Apache Log4j.

Bytecode (Java 8) for Apache Log4j API is provided in a separate JAR file like log4j-api-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 API 2.14.1 below.

⏎ org/apache/logging/log4j/util/StringMap.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.util;

/**
 * Exposes methods to add and remove key-value pairs to and from {@code ReadOnlyStringMap}.
 *
 * @see ReadOnlyStringMap
 * @since 2.7
 */
public interface StringMap extends ReadOnlyStringMap {

    /**
     * Removes all key-value pairs from this collection.
     * @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
     *          to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
     *          {@link #forEach(TriConsumer, Object)}.
     * @throws UnsupportedOperationException if this collection has been {@linkplain #isFrozen() frozen}.
     */
    void clear();

    /**
     * Indicates whether some other object is "equal to" this one.
     *
     * @param obj
     *            the reference object with which to compare.
     * @return {@code true} if this object is the same as the obj argument; {@code false} otherwise.
     * @see #hashCode()
     */
    @Override
    boolean equals(final Object obj);

    /**
     * Makes this collection immutable. Attempts to modify the collection after the {@code freeze()} method was called
     * will result in an {@code UnsupportedOperationException} being thrown.
     */
    void freeze();

    /**
     * Returns a hash code value for the object.
     * @return a hash code value for this object.
     */
    @Override
    int hashCode();

    /**
     * Returns {@code true} if this object has been {@linkplain #freeze() frozen}, {@code false} otherwise.
     * @return  {@code true} if this object has been {@linkplain #freeze() frozen}, {@code false} otherwise
     */
    boolean isFrozen();

    /**
     * Copies all key-value pairs from the specified {@code ReadOnlyStringMap} into this {@code StringMap}.
     * @param source the {@code ReadOnlyStringMap} to copy key-value pairs from
     * @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
     *          to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
     *          {@link #forEach(TriConsumer, Object)}.
     * @throws UnsupportedOperationException if this collection has been {@linkplain #isFrozen() frozen}.
     */
    void putAll(final ReadOnlyStringMap source);

    /**
     * Puts the specified key-value pair into the collection.
     *
     * @param key the key to add or remove. Keys may be {@code null}.
     * @param value the value to add. Values may be {@code null}.
     * @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
     *          to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
     *          {@link #forEach(TriConsumer, Object)}.
     * @throws UnsupportedOperationException if this collection has been {@linkplain #isFrozen() frozen}.
     */
    void putValue(final String key, final Object value);

    /**
     * Removes the key-value pair for the specified key from this data structure.
     *
     * @param key the key to remove. May be {@code null}.
     * @throws java.util.ConcurrentModificationException some implementations may not support structural modifications
     *          to this data structure while iterating over the contents with {@link #forEach(BiConsumer)} or
     *          {@link #forEach(TriConsumer, Object)}.
     * @throws UnsupportedOperationException if this collection has been {@linkplain #isFrozen() frozen}.
     */
    void remove(final String key);
}

⏎ org/apache/logging/log4j/util/StringMap.java

Or download all of them as a single archive file:

File name: log4j-api-2.14.1-sources.jar
File size: 264773 bytes
Release date: 2021-03-06
Download 

⇒ Source Code for Apache Log4j Core Implementation

⇐ Downloading Apache Log4j Binary Package

⇑ Downloading and Reviewing Apache Log4j Packages

⇑⇑ FAQ for Apache Log4j