作用域 | 描述 |
singleton | 单例模式,IOC容器仅生成和管理一个bean实例,是默认的作用域 |
prototype | 多例模式,IOC容器将为每次请求创建一个新的实例 |
request | 在一次HTTP请求中返回一个bean实例,不同的HTTP请求返回不同的bean实例 |
session | 在一个HTTP session中,容器返回同一个bean实例 |
application | 为每个ServletContext对象创建一个实例,即同一个应用共享同一个bean实例 |
websocket | 为每个WebSocket对象创建一个bean实例 |
示例------prototype作用域
<?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="constructorInstance" class="instance.BeanClass" scope="prototype">
<!-- scope作用域,singleton单例模式,singleton是scope的默认模式 -->
<!-- scope作用域,prototype多例模式,ioc容器将为每次请求创建一个新的实例 -->
</bean>
<!-- 静态工厂实例化bean -->
<bean id="staticFacoryInstance" class="instance.BeanStaticFactory" factory-method="createInstance">
</bean>
<!-- 配置工厂 -->
<bean id="myFactory" class="instance.BeanInstanceFactory">
</bean>
<!-- 实例工厂实例化bean -->
<bean id="instanceFacoryInstance" factory-bean="myFactory" factory-method="createBeanClassInstance">
</bean>
</beans>
package test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import instance.BeanClass;
public class TestInstance {
public static void main(String[] args) {
ApplicationContext appCon = new ClassPathXmlApplicationContext("applicationContext.xml");
BeanClass b1 = (BeanClass)appCon.getBean("constructorInstance");
System.out.println(b1+b1.message);
BeanClass b6 = (BeanClass)appCon.getBean("constructorInstance");
System.out.println(b6+b6.message);
//测试静态工厂实例化bean
BeanClass b2 =(BeanClass)appCon.getBean("staticFacoryInstance");
System.out.println(b2+b2.message);
//测试实例广场实例化bean
BeanClass b3 =(BeanClass)appCon.getBean("instanceFacoryInstance");
System.out.println(b3+b3.message);
}
}