实现 FactoryBean 接口在 Spring IOC 容器中配置 Bean
•Spring 中有两种类型的 Bean, 一种是普通Bean, 另一种是工厂Bean, 即FactoryBean.
•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
代码示例:
package com.qiqi.spring.beans.beanFacyory;
public class Car {
private String brand;
private double price;
public String getBrand() {
return brand;
}
public void setBrand(String brand) {
this.brand = brand;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
@Override
public String toString() {
return "Car [brand=" + brand + ", price=" + price + "]";
}
public Car() {
System.out.println(".......");
}
public Car(String brand, double price) {
super();
this.brand = brand;
this.price = price;
}
}
package com.qiqi.spring.beans.beanFacyory;
import org.springframework.beans.factory.FactoryBean;
public class CarFactoryBean implements FactoryBean<Car>{
private String brand;
public void setBrand(String brand) {
this.brand = brand;
}
@Override
public Car getObject() throws Exception {
// TODO Auto-generated method stub
return new Car(brand, 300000);
}
@Override
public Class<?> getObjectType() {
// TODO Auto-generated method stub
return null;
}
@Override
public boolean isSingleton() {
// TODO Auto-generated method stub
return false;
}
}
public class Main {
public static void main(String[] args) {
ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-beanFactory.xml");
Car car = (Car) ctx.getBean("car");
System.out.println(car);
}
}
<?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.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
-->
<bean id="car" class="com.qiqi.spring.beans.beanFacyory.CarFactoryBean">
<property name="brand" value="BMW"></property>
</bean>
</beans>