Apache BCEL Source Code Files are inside the Apache BCEL source package file like bcel-6.6.1-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 BCEL 6.6.1 in \Users\fyicenter\bcel-6.6.1\src:

⏎ org/apache/bcel/util/SyntheticRepository.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.bcel.util;

import java.util.HashMap;
import java.util.Map;

/**
 * This repository is used in situations where a Class is created outside the realm of a ClassLoader. Classes are loaded
 * from the file systems using the paths specified in the given class path. By default, this is the value returned by
 * ClassPath.getClassPath().
 * <p>
 * This repository uses a factory design, allowing it to maintain a collection of different classpaths, and as such It
 * is designed to be used as a singleton per classpath.
 * </p>
 *
 * @see org.apache.bcel.Repository
 */
public class SyntheticRepository extends MemorySensitiveClassPathRepository {

    // private static final String DEFAULT_PATH = ClassPath.getClassPath();
    private static final Map<ClassPath, SyntheticRepository> MAP = new HashMap<>(); // CLASSPATH X REPOSITORY

    public static SyntheticRepository getInstance() {
        return getInstance(ClassPath.SYSTEM_CLASS_PATH);
    }

    public static SyntheticRepository getInstance(final ClassPath classPath) {
        return MAP.computeIfAbsent(classPath, SyntheticRepository::new);
    }

    private SyntheticRepository(final ClassPath path) {
        super(path);
    }
}

⏎ org/apache/bcel/util/SyntheticRepository.java

Or download all of them as a single archive file:

File name: bcel-6.6.1-sources.jar
File size: 688374 bytes
Release date: 2022-09-18
Download 

⇒ Install Apache BCEL 6.5.0 Binary Package

⇐ Download and Install Apache BCEL Source Package

⇑ Apache BCEL (Byte Code Engineering Library)

⇑⇑ Java Bytecode Tools