public static void main(String[] args) throws Exception {   String name = "Xiao Ming";   int age = 20;   Person p = new Person();   // TODO: 利用反射调用setName和setAge方法:   Class<Person> personClass = Person.class;   Method setName = personClass.getDeclaredMethod("setName", String.class);   Method setAge = personClass.getDeclaredMethod("setAge", int.class);   setName.invoke(p,name);   setAge.invoke(p,age);   System.out.println(p.getName()); // "Xiao Ming"   System.out.println(p.getAge()); // 20}