Class.ForName()读取配置文件

• 榨汁机(Juicer)榨汁的案例

• 分别有水果(Fruit)苹果(Apple)香蕉(Banana)桔子(Orange)榨汁(squeeze)

• public class Demo_Reflect {
  
      /**
       * 榨汁机(Juicer)榨汁的案例
       * 分别有水果(Fruit)苹果(Apple)香蕉(Banana)桔子(Orange)榨汁(squeeze)
       * @throws Exception
       */
      public static void main(String[] args) throws Exception {
          /*Juicer j = new Juicer();
          //j.run(new Apple());
          j.run(new Orange());*/
          BufferedReader br = new BufferedReader(new FileReader("config.properties"));    //创建输入流对象,关联配置文件
          Class<?> clazz = Class.forName(br.readLine());                                  //读取配置文件一行内容,获取该类的字节码对象
          Fruit f = (Fruit) clazz.newInstance();                                          //通过字节码对象创建实例对象
          Juicer j = new Juicer();
          j.run(f);
      }
  
  }
  interface Fruit {
      public void squeeze();
  }
  
  class Apple implements Fruit {
      public void squeeze() {
          System.out.println("榨出一杯苹果汁儿");
      }
  }
  
  class Orange implements Fruit {
      public void squeeze() {
          System.out.println("榨出一杯桔子汁儿");
      }
  }
  
  class Juicer {
      public void run(Fruit f) {
          f.squeeze();
      }
  
  }