1、自定义一个类实现由spring提供的FactoryBean接口
2、配置文件:
通过FactoryBean来配置bean的实例
class:指向FactoryBean的实现类的全类名
property:配置实现类的属性
配置完成后,实际上返回的bean的实例是有实现类中的getObject()方法返回的实例
一个例子:
Car类:
public class Car {
private String brand;
private double price;
public void setBrand(String brand) {
this.brand = brand;
}
public void setPrice(double price) {
this.price = price;
}
public Car() {
super();
// TODO Auto-generated constructor stub
}
public Car(String brand, double price) {
super();
this.brand = brand;
this.price = price;
}
@Override
public String toString() {
return "Car [brand=" + brand + ", price=" + price + "]";
}
}
FactoryBean的实现类:
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,3000000.0);
}
//返回bean的类型
@Override
public Class<?> getObjectType() {
// TODO Auto-generated method stub
return Car.class;
}
//是不是单例的
@Override
public boolean isSingleton() {
// TODO Auto-generated method stub
return true;
}
}
配置文件:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="car" class="cn.com.demo04.CarFactoryBean">
<property name="brand" value="aodi"></property>
</bean>
</beans>
测试类:
public class Test {
public static void main(String[] args) {
ApplicationContext ctx=new ClassPathXmlApplicationContext("FactoryBean.xml");
Car car=(Car) ctx.getBean("car");
System.out.println(car);
}
}