TestGoods.java

package com.zoro.reflect;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class TestGoods {

    public static void main(String[] args) {

        try {
            Class goodsClass = Class.forName("com.zoro.reflect.Goods");
            Constructor constructor = goodsClass.getConstructor(new Class[]{
                    String.class, String.class, double.class, String.class
            });

            Goods goods2 = (Goods)constructor.newInstance(new Object[]{
                    "001", "mooc手机", 3999, "6.58英寸大屏， 超长待机"});
            System.out.println(goods2);

            String newDesc = "6.58英寸大屏，超长待机，超级快充，6400万高清四摄";
            System.out.println("商品描述信息更改为：" + newDesc);

            Method method = goodsClass.getMethod("display", String.class);
            method.invoke(goods2, newDesc);
            System.out.println(goods2);

        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }

    }

}

Goods.java

​package com.zoro.reflect;
public class Goods {

    private String num;
    private String title;
    private double price;
    private String desc;

    public Goods() {
    }

    public Goods(String num, String title, double price, String desc) {
        this.setNum(num);
        this.setTitle(title);
        this.setPrice(price);
        this.setDesc(desc);
    }

    public String getNum() {
        return num;
    }

    public void setNum(String num) {
        this.num = num;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public String getDesc() {
        return desc;
    }

    public void setDesc(String desc) {
        this.desc = desc;
    }

    @Override
    public String toString() {
        return "Goods{" +
                "num='" + num + '\'' +
                ", title='" + title + '\'' +
                ", price=" + price +
                ", desc='" + desc + '\'' +
                '}';
    }

    public void display(String desc) {
       this.setDesc(desc);
    }

}