程序代码：

package fanshe.ConstructorDemo;
import java.lang.reflect.Constructor;
class Person
{
    private int age;
    private String name;
    Person()
    {
       
    }
    Person(String name,int age)
    {
        this.name=name;
        this.age=age;   
    }
    public void setName(String name)
    {
        this.name=name;
    }
    public String getName()
    {
        return this.name;
    }
    public void setAge(int age)
    {
        this.age=age;
    }
    public int getAge()
    {
        return this.age;
    }
    public String toString()
    {
        return "姓名："+this.name+"\r\n"+"年龄："+this.age;
    }
}
public class InstanceDemo04
{
    public static void main(String[] args)
    {
        Class<?> c=null;
        try
        {
            c=Class.forName("fanshe.ConstructorDemo.Person");
        }
        catch(ClassNotFoundException e)
        {
            e.printStackTrace();
        }
        Person per=null;
        Constructor<?>[] cons = null ;
        cons=c.getConstructors();
        try
        {
            per=(Person)cons[1].newInstance("java爱好者",20);
            //per=(Person)cons[0].newInstance();
        }
        catch(Exception e2)
        {
            e2.printStackTrace();
        }
        //per.setAge(20);per.setName("java爱好者");
        System.out.println(per);
    }
}