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/attribute/BaseIfAttribute.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.attribute;

import java.util.Map;
import java.util.stream.Collectors;

import org.apache.tools.ant.ProjectComponent;
import org.apache.tools.ant.UnknownElement;


/**
 * An abstract class for if/unless attributes.
 * This contains a boolean flag to specify whether this is an
 * if or unless attribute.
 * @since Ant 1.9.1
 */
public abstract class BaseIfAttribute
    extends ProjectComponent implements EnableAttribute {
    private boolean positive = true;
    /**
     * Set the positive flag.
     * @param positive the value to use.
     */
    protected void setPositive(boolean positive) {
        this.positive = positive;
    }

    /**
     * Get the positive flag.
     * @return the flag.
     */
    protected boolean isPositive() {
        return positive;
    }

    /**
     * convert the result.
     * @param val the result to convert
     * @return val if positive or !val if not.
     */
    protected boolean convertResult(boolean val) {
        return positive == val;
    }

    /**
     * Get all the attributes in the ant-attribute:param
     * namespace and place them in a map.
     * @param el the element this attribute is in.
     * @return a map of attributes.
     */
    protected Map<String, String> getParams(UnknownElement el) {
        // this makes a copy!
        return el.getWrapper().getAttributeMap().entrySet().stream()
                .filter(e -> e.getKey().startsWith("ant-attribute:param"))
                .collect(Collectors.toMap(e -> e.getKey().substring(e.getKey().lastIndexOf(':') + 1),
                        e -> el.getProject().replaceProperties((String) e.getValue()), (a, b) -> b));
    }
}

⏎ org/apache/tools/ant/attribute/BaseIfAttribute.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
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