Table 3.3. Bean scopes

Scope Description

singleton

(Default) Scopes a single bean definition to a single object instance per Spring IoC container.

prototype

Scopes a single bean definition to any number of object instances.

request

Scopes a single bean definition to the lifecycle of a single HTTP request; that is, each HTTP request has its own instance of a bean created off the back of a single bean definition. Only valid in the context of a web-aware Spring ApplicationContext.

session

Scopes a single bean definition to the lifecycle of an HTTP Session. Only valid in the context of a web-aware Spring ApplicationContext.

global session

Scopes a single bean definition to the lifecycle of a global HTTP Session. Typically only valid when used in a portlet context. Only valid in the context of a web-aware Spring ApplicationContext.
<?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:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="
http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context 
    http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <!-- a service object; we will be profiling its methods -->

    <bean name="u" class="com.bebig.dao.impl.UserDAOImpl" />
    <!-- scope值为singleton，表示单例，同一个对象仅有一个，每次得到的是同一个对象
    scope值为proptotype，表示每次创建新的对象
     -->
    <bean id="userService" class="com.bebig.service.UserService" scope="prototype">
        <constructor-arg>
            <ref bean="u" />
        </constructor-arg>
    </bean>

</beans>