动态代理的实现（基于匿名内部类）

public interface BuyPhoneService {
    void buyPhone(String phone);
}

public class BuyPhoneServiceImpl implements BuyPhoneService {
    @Override
    public void buyPhone(String phone) {
        System.out.println("买"+ phone +"手机");
    }
}

public class Xc {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, InvocationTargetException, IllegalAccessException {
        BuyPhoneService buyPhoneService = new BuyPhoneServiceImpl();
        BuyPhoneService aa = (BuyPhoneService) Proxy.newProxyInstance(buyPhoneService.getClass().getClassLoader(), buyPhoneService.getClass().getInterfaces(),
                new InvocationHandler() {
                    @Override
                    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                        System.out.println("增强");
                        Object invoke = method.invoke(buyPhoneService, "华为");
                        System.out.println("增强");
                        return invoke;
                    }
                });
        aa.buyPhone("小米");
    }
}