反这类的构造函数（写框架时才会用到反射类）

package reflet;

import java.util.List;

public class person {
    public String name="hahaah";
    public person()//无参构造函数
    {
        System.out.println("person");
    }
    public person(String name)//有参构造函数
    {
        System.out.println(name);
    }
    public person(String name,int password)//有参构造函数
    {
        System.out.println(name+":"+password);
    }
    private person(List list)//有参构造函数
    {
        System.out.println("person list");
    }

 

package reflet;

import java.lang.reflect.Constructor;
import java.util.ArrayList;
import java.util.List;

import org.junit.Test;

//反射类的构造函数，创建类的对象
public class demo {
   //反射构造函数：public person
    @Test
    public void test1() throws Exception
    {
      Class clazz=Class.forName("reflet.person");//加载类
      Constructor c=clazz.getConstructor(null);
      person p=(person)c.newInstance(null);
      System.out.println(p.name);
    }
    //反射构造函数：public person(String name)
    @Test
    public void test2() throws Exception
    {
      Class clazz=Class.forName("reflet.person");
      Constructor c=clazz.getConstructor(String.class);
      person p=(person)c.newInstance("sdqawjuhugbyugdr");
      System.out.println(p.name);
    }
    //反射构造函数：public person(String name,int password)
        @Test
        public void test3() throws Exception
        {
          Class clazz=Class.forName("reflet.person");
          Constructor c=clazz.getConstructor(String.class,int.class);
          person p=(person)c.newInstance("sdqawjuhugbyugdr",45);
          System.out.println(p.name);
        }
        //反射构造函数：private person(List list)
        @Test
        public void test4() throws Exception
        {
          Class clazz=Class.forName("reflet.person");
          Constructor c=clazz.getDeclaredConstructor(List.class);//因为此函数是private类型，所以用getDeclaredConstructor
          c.setAccessible(true);//暴力反射（作用是让私有可以被外界访问）
          person p=(person)c.newInstance(new ArrayList());
          System.out.println(p.name);
        }
        //创建对象的另外一种途径：以下test5等效于test1
        @Test
        public void test5() throws Exception
        {
          Class clazz=Class.forName("reflet.person");
          person p=(person) clazz.newInstance();
          System.out.println(p.name);
        }    
}