java反射简单实例

本文实例讲述了java反射简单实现方法。分享给大家供大家参考。具体实现方法如下：

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();
  }
 }
}

结果为：

有配置文件！
eat apple

希望本文所述对大家的java程序设计有所帮助。