Apache Ant Source Code Files are inside the Apache Ant source package file like apache-ant-1.10.10-src.zip. Unzip the source package file and go to the "src/main" sub-directory, you will see source code files.

Here is the list of Java source code files of the Apache Ant 1.10.10 in \Users\fyicenter\apache-ant-1.10.10\src\main:

⏎ org/apache/tools/ant/listener/Log4jListener.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
 *
 *      https://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.tools.ant.listener;

import org.apache.log4j.Logger;
import org.apache.tools.ant.BuildEvent;
import org.apache.tools.ant.BuildListener;
import org.apache.tools.ant.MagicNames;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.Target;
import org.apache.tools.ant.Task;


/**
 * Listener which sends events to Log4j logging system.
 * @deprecated Apache Log4j (1) is not developed any more. Last
 *     release is 1.2.17 from 26-May-2012 and contains vulnerability issues.
 *     Use the standard listener or your own custom listener instead.
 */
@Deprecated
public class Log4jListener implements BuildListener {

    /**
     * log category we log into
     * @deprecated use MagicNames.ANT_CORE_PACKAGE
     */
    @Deprecated
    public static final String LOG_ANT = MagicNames.ANT_CORE_PACKAGE;

    /**
     * Construct the listener
     */
    public Log4jListener() {
        // trigger the log4j initialization (if at all it's not yet initialized)
        @SuppressWarnings("unused")
        final Logger log = Logger.getLogger(MagicNames.ANT_CORE_PACKAGE);
    }

    /**
     * @see BuildListener#buildStarted
     * {@inheritDoc}.
     */
    @Override
    public void buildStarted(final BuildEvent event) {
        final Logger log = Logger.getLogger(Project.class.getName());
        log.info("Build started.");
    }

    /**
     * @see BuildListener#buildFinished
     * {@inheritDoc}.
     */
    @Override
    public void buildFinished(final BuildEvent event) {
        final Logger log = Logger.getLogger(Project.class.getName());
        if (event.getException() == null) {
            log.info("Build finished.");
        } else {
            log.error("Build finished with error.", event.getException());
        }
    }

    /**
     * @see BuildListener#targetStarted
     * {@inheritDoc}.
     */
    @Override
    public void targetStarted(final BuildEvent event) {
        final Logger log = Logger.getLogger(Target.class.getName());
        log.info("Target \"" + event.getTarget().getName() + "\" started.");
    }

    /**
     * @see BuildListener#targetFinished
     * {@inheritDoc}.
     */
    @Override
    public void targetFinished(final BuildEvent event) {
        final String targetName = event.getTarget().getName();
        final Logger cat = Logger.getLogger(Target.class.getName());
        if (event.getException() == null) {
            cat.info("Target \"" + targetName + "\" finished.");
        } else {
            cat.error("Target \"" + targetName
                + "\" finished with error.", event.getException());
        }
    }

    /**
     * @see BuildListener#taskStarted
     * {@inheritDoc}.
     */
    @Override
    public void taskStarted(final BuildEvent event) {
        final Task task = event.getTask();
        final Logger log = Logger.getLogger(task.getClass().getName());
        log.info("Task \"" + task.getTaskName() + "\" started.");
    }

    /**
     * @see BuildListener#taskFinished
     * {@inheritDoc}.
     */
    @Override
    public void taskFinished(final BuildEvent event) {
        final Task task = event.getTask();
        final Logger log = Logger.getLogger(task.getClass().getName());
        if (event.getException() == null) {
            log.info("Task \"" + task.getTaskName() + "\" finished.");
        } else {
            log.error("Task \"" + task.getTaskName()
                + "\" finished with error.", event.getException());
        }
    }

    /**
     * @see BuildListener#messageLogged
     * {@inheritDoc}.
     */
    @Override
    public void messageLogged(final BuildEvent event) {
        Object categoryObject = event.getTask();
        if (categoryObject == null) {
            categoryObject = event.getTarget();
            if (categoryObject == null) {
                categoryObject = event.getProject();
            }
        }

        final Logger log
            = Logger.getLogger(categoryObject.getClass().getName());
        switch (event.getPriority()) {
            case Project.MSG_ERR:
                log.error(event.getMessage());
                break;
            case Project.MSG_WARN:
                log.warn(event.getMessage());
                break;
            case Project.MSG_INFO:
                log.info(event.getMessage());
                break;
            case Project.MSG_VERBOSE:
            case Project.MSG_DEBUG:
                log.debug(event.getMessage());
                break;
            default:
                log.error(event.getMessage());
                break;
        }
    }
}

⏎ org/apache/tools/ant/listener/Log4jListener.java

Or download all of them as a single archive file:

File name: apache-ant-1.10.10-fyi.zip
File size: 2392938 bytes
Release date: 2021-04-17
Download 

⇒ ant-1.8.0.jar - Apache Ant

⇐ Download Apache Ant Source Package

⇑ Apache Ant - Java Build Tool

⇑⇑ Java/JAR Tools