Spring4.0学习笔记 —— 通过FactoryBean配置Bean

Posted 2020-06-26 cklovefan

1、实现Spring 提供的FactoryBean接口

package com.spring.facoryBean;

import org.springframework.beans.factory.FactoryBean;

public class CarFactoryBean implements FactoryBean<Car> {

    private String brand;
    
    public void setBrand(String brand) {
        this.brand = brand;
    }

    public Car getObject() throws Exception {
        return new Car(brand);
    }

    public Class<?> getObjectType() {
        return Car.class;
    }

    public boolean isSingleton() {
        return true;
    }
}

2、配置xml文件

<?xml version="1.0" encoding="UTF-8"?>
<beans
    xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">


    <!-- 
        通过FactoryBean 来配置Bean 的实例
        class : 指向FactoryBean的全类名
        property : 配置FactoryBean的属性
        
        实际返回的是FactoryBean 的 getObject 方法的得到的实例
    
     -->
    <bean id="car" class="com.spring.facoryBean.CarFactoryBean">
        <property name="brand" value="BMW"></property>
    </bean>
</beans>

3、bean文件

package com.spring.facoryBean;

public class Car {
    
    public Car(String brand) {
        this.brand = brand;
    }

    @Override
    public String toString() {
        return "Car [brand=" + brand + "]";
    }

    private String brand;
    
    public void setBrand(String brand){
        System.out.println("setBrand...");
        this.brand = brand;
    }
    
    public void init(){
        System.out.println("init...");
    }
    
    public void destroy(){
        System.out.println("destroy...");
    }
    
}

4、main方法实现

package com.spring.facoryBean;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class main {
    public static void main(String[] args) {
        ApplicationContext ctx = new ClassPathXmlApplicationContext("bean-beanFactory.xml");
        Car car = (Car)ctx.getBean("car");
        System.out.println(car);
    }
}