public class Test {
	public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, IOException {
		URL[] urls = new URL[] {new URL("http://192.168.119.132:8080/images/animal.jar")};
		URLClassLoader classLoader = new URLClassLoader(urls);
		//加載類以后就可以得到 Class 對(duì)象了
		Class<?> clazz = classLoader.loadClass("com.learn.animal.Dog");
		classLoader.close();  //加載完類以后就可以刪除了。
		//關(guān)閉 classLoader， 否則會(huì)造成 資源泄露  Resource leak
		//這里不使用默認(rèn)的構(gòu)造器，使用帶參數(shù)的構(gòu)造器 獲取特殊的構(gòu)造器
		Constructor<?> con = clazz.getDeclaredConstructor(String.class, int.class, int.class);
		//使用構(gòu)造器創(chuàng)建對(duì)象
		Object ob = con.newInstance("小黑",12,50);
		//在調(diào)用 Dog 對(duì)象的 say 方法，返回對(duì) Dog 對(duì)象自己的描述
		Method mtd0 = clazz.getMethod("say", new Class<?>[] {});  
		String dogSay = (String)mtd0.invoke(ob, new Object[] {});  
		System.out.println(dogSay);
		//再使用setter 方法，改變屬性  模擬 Dog 對(duì)象，逐漸長(zhǎng)大，變胖  哈哈！
		System.out.println("Three years later......");
		Method mtd1 = clazz.getMethod("setAge", int.class);
		mtd1.invoke(ob, 15);
		Method mtd2 = clazz.getMethod("setWeight", int.class);
		mtd2.invoke(ob, 70);
		//注意這些方法是有返回值的！  返回值都是 Object 類型，需要自己強(qiáng)轉(zhuǎn)類型
		dogSay = (String)mtd0.invoke(ob, new Object[] {});  
		System.out.println(dogSay);
		System.out.println("It's over!");
	}
}