spEL
根据工厂方法配置bean
<?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-3.1.xsd">
<!-- 通过静态工厂方法配置bean,注意不是配置静态工厂方法实例,而是bean实例 -->
<!--
class属性:指向静态工厂方法的全类名
factory-method:指向静态工厂方法名
constructor-arg:如果工厂方法需要传入参数,则使用constructor-arg来配置参数
-->
<bean id = "car1" class = "com.spring.factory.StaticCarFactory"
factory-method="getCar">
<constructor-arg value = "audi"></constructor-arg>
</bean>
<!-- 配置工厂实例 -->
<bean id = "carFactory" class = "com.spring.factory.InstanceCarFactory"></bean>
<!-- 通过实例工厂方法来配置bean -->
<!--
factory-bean:指向实例工厂方法的bean
factory-method:指向静态工厂方法名
constructor-arg:如果工厂方法需要传入参数,则使用constructor-arg来配置参数
-->
<bean id = "car2" factory-bean="carFactory" factory-method="getCar">
<constructor-arg value = "ford"></constructor-arg>
</bean>
</beans>
/**
*
* 静态工厂方法:直接调用某一个类的静态方法,就可以返回bean的实例
*
*/
public class StaticCarFactory {
private static Map<String, Car> cars = new HashMap<String, Car>();
static{
cars.put("audi", new Car("Audi",300000));
cars.put("ford", new Car("ford",400000));
}
//静态工厂方法
public static Car getCar(String name){
return cars.get(name);
}
}
/**
*
* 实例工厂的方法,即需要创建工厂本身,
*
*/
public class InstanceCarFactory {
private Map<String, Car> cars = null;
public InstanceCarFactory(){
cars = new HashMap<String, Car>();
cars.put("audi", new Car("Audi",300000));
cars.put("ford", new Car("ford",400000));
}
public Car getCar(String name){
return cars.get(name);
}
}