第四课：通过配置文件获取对象（Spring框架中的IOC和DI的底层就是基于这样的机制）

package com.hero;

public class Hero {
    String name;
    int id;

    public Hero() {
        super();
        // TODO Auto-generated constructor stub
    }

    public Hero(String name, int id) {
        super();
        this.name = name;
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    static String copyright;

    static {
        System.out.println("初始化 copyright");
        copyright = "版权由Riot Games公司所有";
    }

    @Override
    public String toString() {
        return "Hero [name=" + name + ", id=" + id + "]";
    }

}

package com.hero;
 
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
 
 
public class TestReflection4 {
    public static void main(String[] args) throws InterruptedException {
        Hero h = getHero();
        System.out.println(h);
    }
 
    public static Hero getHero() {
 
        File f = new File("D:/hero.txt");
 
        try (FileReader fr = new FileReader(f)) {
            String className = null;
            char[] all = new char[(int) f.length()];
　　//把文件里的数据读到all这个char数组里面
            fr.read(all);
　　//String的构造方法，也可以用className=String.valueOf(all);
            className = new String(all);
            Class clazz=Class.forName(className);
            Constructor c= clazz.getConstructor();
            Hero h= (Hero) c.newInstance();
            h.setName("a");
            return h;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
         
    }
}