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/message/MessageFactory.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.message;

/**
 * Creates messages. Implementations can provide different message format syntaxes.
 *
 * @see ParameterizedMessageFactory
 * @see StringFormatterMessageFactory
 */
public interface MessageFactory {

    /**
     * Creates a new message based on an Object.
     *
     * @param message
     *            a message object
     * @return a new message
     */
    Message newMessage(Object message);

    /**
     * Creates a new message based on a String.
     *
     * @param message
     *            a message String
     * @return a new message
     */
    Message newMessage(String message);

    /**
     * Creates a new parameterized message.
     *
     * @param message
     *            a message template, the kind of message template depends on the implementation.
     * @param params
     *            the message parameters
     * @return a new message
     * @see ParameterizedMessageFactory
     * @see StringFormatterMessageFactory
     */
    Message newMessage(String message, Object... params);
}

⏎ org/apache/logging/log4j/message/MessageFactory.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