Java 反射基础

三种方式获取对象类型：

package com.helen.test;

import java.util.Date;

public class Reflect {
public static void main(String[] args) {
    Date date=new Date();
    System.out.println(date.getClass().getName());
    
    Class<?> clas=java.util.Date.class;
    System.out.println(clas.getName());
    

    try {
        Class<?> clas1 = Class.forName("java.util.Date");
        System.out.println(clas1.getName());
    } catch (ClassNotFoundException e) {
        
        e.printStackTrace();
    }
    
}
}

 

 

利用反射实现工厂模式

package com.helen.test;

import java.util.Date;

interface Fruit {
    public void eat();
}

class Apple implements Fruit {

    public void eat() {
        System.out.println("helen eat 苹果！");
    }

}

class Orange implements Fruit {

    public void eat() {
        System.out.println("helen eat 橘子！");
    }

}

class Factory {
    public static Fruit getFruit(String className) {
        Fruit fruit = null;
        try {
            Class<?> clas = Class.forName(className);
            fruit = (Fruit) clas.newInstance();  //实例一个对象

        } catch (Exception e) {

            e.printStackTrace();
        }
        return fruit;

    }
}

public class Reflect_Factory {
    public static void main(String[] args) {
        Fruit fruit=Factory.getFruit("com.helen.test.Apple");
        Fruit fruit1=Factory.getFruit("com.helen.test.Orange");
        fruit.eat();
        fruit1.eat();
    }
}