> 可用于动态加载jar包中的类 1. 加载网络jar包类 ``` URL url = new URL("http://open.baidu.cn/class/test.jar"); URL[] urls = new URL[1]; urls[0] = url; URLClassLoader loader = new URLClassLoader(urls); Class clazz = loader.loadClass("com.p8.test.p8test"); dahua dh = (dahua) clazz.newInstance(); String value = dh.getValue(); System.out.println(value); ``` 2. 加载本地jar包 ``` public static void main(String[] args) throws Exception { // 创建一个URL数组 File file = new File("/Users/fengxiansheng/Downloads/parse.jar"); URL[] urls = new URL[]{file.toURI().toURL()}; //这时候 myClassLoader 的 parent 是 AppClassLoader URLClassLoader myClassLoader = new URLClassLoader(urls); Class<?> aClass = myClassLoader.loadClass("com.test.ParseExcel"); Object obj = aClass.newInstance();//利用反射创建对象 Method method = aClass.getMethod("parse");//获取parse方法 method.invoke(obj,null); } ```