自定义类加载器

package com.lms.db.driver;
import java.io.File;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;
/**
 * @description: 使用URLClassLoader加载
 * @author: pp_lan
 * @date: 2022/3/17
 */
public class UrlExternalClasspathLoader  {
    private  final URLClassLoader urlClassLoader;
    /**
     * 构造方法
     * @param file jar所在的路径，或者单个jar的全路径
     */
    public UrlExternalClasspathLoader(File file,ClassLoader parent) throws Exception {
        List<URL> urlList = new ArrayList<>();
        if (file.isDirectory()) {
            addUrl(urlList, file);
        } else {
            addJar(urlList, file);
        }
        URL[] urls = urlList.toArray(new URL[]{});
        urlClassLoader = new URLClassLoader(urls,parent);
    }
    public UrlExternalClasspathLoader(File file) throws Exception {
        List<URL> urlList = new ArrayList<>();
        if (file.isDirectory()) {
            addUrl(urlList, file);
        } else {
            addJar(urlList, file);
        }
        URL[] urls = urlList.toArray(new URL[]{});
        urlClassLoader = new URLClassLoader(urls);
    }
    public void init() {
    }
    /**
     * 加载class
     * @param name
     * @return
     * @throws ClassNotFoundException
     */
    public Class<?> loadClass(String name) throws ClassNotFoundException {
        return this.urlClassLoader.loadClass(name);
    }
    /**
     * 加载路径
     * @param urlList
     * @param file
     */
    private void addUrl(List<URL> urlList, File file) throws Exception {
        File[] subFiles = file.listFiles();
        if (subFiles != null) {
            for (File subFile : subFiles) {
                if (subFile.isDirectory()) {
                    addUrl(urlList, subFile);
                } else {
                    addJar(urlList, subFile);
                }
            }
        }
    }
    /**
     * 加载jar
     * @param urlList
     * @param subFile
     */
    private void addJar(List<URL> urlList, File subFile) throws Exception {
        try {
            if (subFile.getAbsolutePath().endsWith(".jar")) {
                urlList.add(subFile.toURI().toURL());
            }
        } catch (MalformedURLException e) {
            throw new Exception("加载JAR异常");
        }
    }
    public static void main(String[] args) throws Exception {
        System.out.println("开始");
        UrlExternalClasspathLoader classLoader1 = new UrlExternalClasspathLoader(new File("D:\\idea_workspace\\1-tool\\db-driver-manager\\src\\main\\resources\\driver\\dm\\Dm7JdbcDriver.jar"),null);
        UrlExternalClasspathLoader classLoader2 = new UrlExternalClasspathLoader(new File("D:\\idea_workspace\\1-tool\\db-driver-manager\\src\\main\\resources\\driver\\dm\\DmJdbcDriver.jar"),null);
        try {
            Class<?> aClass1 = classLoader1.loadClass("dm.jdbc.driver.DmDriver");
            Object o = aClass1.newInstance();
            System.out.println(o);
            Class<?> aClass2 = classLoader2.loadClass("dm.jdbc.driver.DmDriver");
            Object o2 = aClass2.newInstance();
            System.out.println(o2);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}