ClassloaderUtility.java

/*
 *    Copyright 2006-2026 the original author or authors.
 *
 *    Licensed 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.mybatis.generator.internal.util;

import static org.mybatis.generator.internal.util.messages.Messages.getString;

import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.mybatis.generator.exception.InternalException;

/**
 * This class holds methods useful for constructing custom classloaders.
 *
 * @author Jeff Butler
 */
public class ClassloaderUtility {

    private static final Log LOG = LogFactory.getLog(ClassloaderUtility.class);

    /**
     * Utility Class - No Instances.
     */
    private ClassloaderUtility() {
    }

    public static ClassLoader getCustomClassloader(Collection<String> entries) {
        List<URL> urls = new ArrayList<>();
        Path file;

        for (String classPathEntry : entries) {
            file = Path.of(classPathEntry);
            if (Files.notExists(file)) {
                LOG.warn(getString("Warning.31", classPathEntry)); //$NON-NLS-1$
                continue;
            }

            try {
                urls.add(file.toUri().toURL());
            } catch (MalformedURLException e) {
                // this shouldn't happen, but just in case...
                throw new InternalException(getString("RuntimeError.9", classPathEntry)); //$NON-NLS-1$
            }
        }

        ClassLoader parent = Thread.currentThread().getContextClassLoader();

        return new URLClassLoader(urls.toArray(new URL[0]), parent);
    }
}