package io.kimmking.kmq; import lombok.SneakyThrows; import java.io.File; import java.lang.reflect.Method; import java.net.URL; import java.net.URLClassLoader; public class TestAddUrl { @SneakyThrows public static void main(String[] args) { URLClassLoader classLoader = (URLClassLoader) TestAddUrl.class.getClassLoader(); String dir = "/Users/kimmking/Downloads/Hello"; Method method = URLClassLoader.class.getDeclaredMethod("addURL", URL.class); method.setAccessible(true); method.invoke(classLoader, new File(dir).toURL()); Class klass = Class.forName("Hello",true, classLoader); Object obj = klass.newInstance(); Method hello = klass.getDeclaredMethod("hello"); hello.invoke(obj); } }