> 可用于動態加載jar包中的類 1. 加載網絡jar包類 ``` 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. 加載本地jar包 ``` public static void main(String[] args) throws Exception { // 創建一個URL數組 File file = new File("/Users/fengxiansheng/Downloads/parse.jar"); URL[] urls = new URL[]{file.toURI().toURL()}; //這時候 myClassLoader 的 parent 是 AppClassLoader URLClassLoader myClassLoader = new URLClassLoader(urls); Class<?> aClass = myClassLoader.loadClass("com.test.ParseExcel"); Object obj = aClass.newInstance();//利用反射創建對象 Method method = aClass.getMethod("parse");//獲取parse方法 method.invoke(obj,null); } ```