2l？

package Reflect;
import java.lang.reflect.Constructor;
class Person
{
public Person()
{
}
public Person(String name)
{
this.name = name;
}
public Person(int age)
{
this.age = age;
}
public Person(String name, int age)
{
this.age = age; this.name = name;
}
public String getName()
{
return name;
}
public int getAge()
{
return age;
}
@Override
public String toString()
{
return "[" + this.name + " " + this.age + "]";
}
private String name;
private int age;
}
public class Hello
{
public static void main(String[] args)
{
Class<?> demo = null;
try
{
demo = Class.forName("Reflect.Person");
} catch (Exception e)
{
e.printStackTrace();
}
Person per1 = null;
Person per2 = null;
Person per3 = null;
Person per4 = null;
// 取得全部的构造函数
Constructor<?> cons[] = demo.getConstructors();
try
{
per1 = (Person) cons[0].newInstance();
per2 = (Person) cons[1].newInstance("Rollen");
per3 = (Person) cons[2].newInstance(20);
per4 = (Person) cons[3].newInstance("Rollen", 20);
} catch (Exception e)
{
e.printStackTrace();
}
System.out.println(per1);
System.out.println(per2);
System.out.println(per3);
System.out.println(per4);
}}

帮忙看下，在贴吧贴代码好难啊。

这个是报的错。