Java 反射基础

三种方式获取对象类型：

 1 package com.helen.test;
 2
 3 import java.util.Date;
 4
 5 public class Reflect {
 6 public static void main(String[] args) {
 7     Date date=new Date();
 8     System.out.println(date.getClass().getName());
 9
10     Class<?> clas=java.util.Date.class;
11     System.out.println(clas.getName());
12
13
14     try {
15         Class<?> clas1 = Class.forName("java.util.Date");
16         System.out.println(clas1.getName());
17     } catch (ClassNotFoundException e) {
18
19         e.printStackTrace();
20     }
21
22 }
23 }

利用反射实现工厂模式

 1 package com.helen.test;
 2
 3 import java.util.Date;
 4
 5 interface Fruit {
 6     public void eat();
 7 }
 8
 9 class Apple implements Fruit {
10
11     public void eat() {
12         System.out.println("helen eat 苹果！");
13     }
14
15 }
16
17 class Orange implements Fruit {
18
19     public void eat() {
20         System.out.println("helen eat 橘子！");
21     }
22
23 }
24
25 class Factory {
26     public static Fruit getFruit(String className) {
27         Fruit fruit = null;
28         try {
29             Class<?> clas = Class.forName(className);
30             fruit = (Fruit) clas.newInstance();  //实例一个对象
31
32         } catch (Exception e) {
33
34             e.printStackTrace();
35         }
36         return fruit;
37
38     }
39 }
40
41 public class Reflect_Factory {
42     public static void main(String[] args) {
43         Fruit fruit=Factory.getFruit("com.helen.test.Apple");
44         Fruit fruit1=Factory.getFruit("com.helen.test.Orange");
45         fruit.eat();
46         fruit1.eat();
47     }
48 }