package reflect; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.util.Properties; interface fruit{  public abstract void eat() ; } class Apple implements fruit{  public void eat() {   System.out.println("eat Apple");  }   } class orange implements fruit{  public void eat() {   System.out.println("eat orange");  }   } class init{  public static Properties getPro() throws FileNotFoundException, IOException{   Properties pro = new Properties() ;   File f = new File("fruit.properties") ;   if(f.exists()){    System.out.println("有配置文件！");    //从配置文件中读取键值对    pro.load(new FileInputStream(f)) ;   }else{    System.out.println("没有配置文件！");    pro.setProperty("apple", "reflect.Apple") ;    pro.setProperty("orange", "reflect.orange") ;    pro.store(new FileOutputStream(f), "FRUIT CLASS");   }   return pro ;  } } class Factory{  public static fruit getInstance(String className){   fruit f = null ;   try {    //通过反射得到fruit的实例对象    f = (fruit)Class.forName(className).newInstance();   } catch (InstantiationException e) {    e.printStackTrace();   } catch (IllegalAccessException e) {    e.printStackTrace();   } catch (ClassNotFoundException e) {    e.printStackTrace();   }   return f ;  } } public class Hello {  public static void main(String[] args) {   try {    Properties pro = init.getPro() ;    fruit f = Factory.getInstance(pro.getProperty("apple")) ;    if(f != null){     f.eat() ;    }   } catch (FileNotFoundException e) {    // TODO Auto-generated catch block    e.printStackTrace();   } catch (IOException e) {    // TODO Auto-generated catch block    e.printStackTrace();   }  } }