java反射类报错

Question

package com.reflect;

public class Hello {

    public static void main(String[] args) {
        Class<?> demo=null;
        try{
            demo=Class.forName("com.reflect.Person");
        }catch (Exception e) {
            e.printStackTrace();
        }
        Person per=null;
        try {
            per=(Person)demo.newInstance();
        } catch (InstantiationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        per.setName("Rollen");
        per.setAge(20);
        System.out.println(per);
    }

}

package com.reflect;

class Person {

    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {

        return name;
    }

    public void setName(String name) {

        this.name = name;
    }

    public int getAge() {

        return age;
    }

    public void setAge(int age) {

        this.age = age;
    }

    @Override
    public String toString() {
        return super.toString();
    }
}

Answer 1

Person类缺少无参构造方法；