Spring_通过Factory配置bean（10）

Love The Way You Lie 2021-09-15 03:40 256阅读 0赞

**实现 FactoryBean 接口在 Spring IOC 容器中配置 Bean**

**   **1、 Spring 中有两种类型的 Bean, 一种是普通Bean, 另一种是工厂Bean, 即FactoryBean.   
   2、工厂 Bean 跟普通Bean不同, 其返回的对象不是指定类的一个实例, 其返回的是该工厂 Bean 的 getObject 方法所返回的对象 。

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> **1、自定义的FactoryBean 需要实现FactoryBean接口:比如  CarFactoryBean.java**

package com.wgs.spring.beans.factorybean;
    
    import org.springframework.beans.factory.FactoryBean;
    
    //自定义的FactoryBean 需要实现FactoryBean接口
    public class CarFactoryBean implements FactoryBean<Car> {
    
    	private String brand;
    	
    	public void setBrand(String brand) {
    		this.brand = brand;
    	}
    	
    	//返回bean的对象
    	@Override
    	public Car getObject() throws Exception {
    		// TODO Auto-generated method stub
    		return new Car(brand,300000);
    	}
    
    	//返回bean的类型
    	@Override
    	public Class<?> getObjectType() {
    		// TODO Auto-generated method stub
    		return Car.class;
    	}
    
    	@Override
    	public boolean isSingleton() {
    		// TODO Auto-generated method stub
    		return true;
    	}
    }

**2、配置文件：beans-beanfactory.xml**

>     <?xml version="1.0" encoding="UTF-8"?>
>     <beans xmlns="http://www.springframework.org/schema/beans"
>     	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>     	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
>     
>     	
>     	<bean id="car" class="com.wgs.spring.beans.factorybean.CarFactoryBean">
>     		<property name="brand" value="Audi"></property>
>     	</bean>
>     
>     </beans>

**3、主函数Main.java**

**    **

package com.wgs.spring.beans.factorybean;
    
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    public class Main {
    	
    	public static void main(String[] args) {
    		
    		ApplicationContext ctx1=new ClassPathXmlApplicationContext("beans-beanfactory.xml");
    		
    		Car car=(Car) ctx1.getBean("car");
    		System.out.println(car);
    	}
    }

**运行结果为：**

> **Car \[brand=Audi, price=300000.0\]**  
>

[70]: /images/20210720/f47ba831aa98492a91edac1dc92cfcb1.png