SLF4J API is a simple API that allows to plug in any desired logging library at deployment time.

Here is the source code for SLF4J API 1.7.31. You can download its pre-compiled version slf4j-api-1.7.31.jar at SLF4J Download Website.

⏎ org/slf4j/IMarkerFactory.java

/**
 * Copyright (c) 2004-2011 QOS.ch
 * All rights reserved.
 *
 * Permission is hereby granted, free  of charge, to any person obtaining
 * a  copy  of this  software  and  associated  documentation files  (the
 * "Software"), to  deal in  the Software without  restriction, including
 * without limitation  the rights to  use, copy, modify,  merge, publish,
 * distribute,  sublicense, and/or sell  copies of  the Software,  and to
 * permit persons to whom the Software  is furnished to do so, subject to
 * the following conditions:
 *
 * The  above  copyright  notice  and  this permission  notice  shall  be
 * included in all copies or substantial portions of the Software.
 *
 * THE  SOFTWARE IS  PROVIDED  "AS  IS", WITHOUT  WARRANTY  OF ANY  KIND,
 * EXPRESS OR  IMPLIED, INCLUDING  BUT NOT LIMITED  TO THE  WARRANTIES OF
 * MERCHANTABILITY,    FITNESS    FOR    A   PARTICULAR    PURPOSE    AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE,  ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */
package org.slf4j;

/**
 * Implementations of this interface are used to manufacture {@link Marker}
 * instances.
 * 
 * <p>See the section <a href="http://slf4j.org/faq.html#3">Implementing 
 * the SLF4J API</a> in the FAQ for details on how to make your logging 
 * system conform to SLF4J.
 * 
 * @author Ceki G&uuml;lc&uuml;
 */
public interface IMarkerFactory {

    /**
     * Manufacture a {@link Marker} instance by name. If the instance has been 
     * created earlier, return the previously created instance. 
     * 
     * <p>Null name values are not allowed.
     *
     * @param name the name of the marker to be created, null value is
     * not allowed.
     *
     * @return a Marker instance
     */
    Marker getMarker(String name);

    /**
     * Checks if the marker with the name already exists. If name is null, then false 
     * is returned.
     *  
     * @param name logger name to check for
     * @return true id the marker exists, false otherwise. 
     */
    boolean exists(String name);

    /**
     * Detach an existing marker.
     * <p>
     * Note that after a marker is detached, there might still be "dangling" references
     * to the detached marker.
     * 
     * 
     * @param name The name of the marker to detach
     * @return whether the marker  could be detached or not
     */
    boolean detachMarker(String name);

    /**
     * Create a marker which is detached (even at birth) from this IMarkerFactory.
     * 
     * @param name marker name
     * @return a dangling marker
     * @since 1.5.1
     */
    Marker getDetachedMarker(String name);
}

⏎ org/slf4j/IMarkerFactory.java

Or download all of them as a single archive file:

File name: slf4j-api-1.7.31-sources.jar
File size: 58728 bytes
Release date: 2021-06-17
Download 

⇒ Source Code for SLF4J 1.7.31 Simple Logging

⇐ Source Code for SLF4J Migrator

⇑ Downloading and Reviewing SLF4J Packages

⇑⇑ SLF4J - Simple Logging Facade for Java