java - Spring Bean 范围

Question

有人能解释一下 Spring bean 中的作用域是什么，我一直只使用“原型(prototype)”，但是我可以用其他参数代替它吗？

我所说的例子

<bean id="customerInfoController" class="com.action.Controller" scope="prototype">
    <property name="accountDao" ref="accountDao"/>
    <property name="utilityDao" ref="utilityDao"/>
    <property name="account_usageDao" ref="account_usageDao"/>  
</bean>

Answer 1

来自 spring specs ，支持 5 种 bean 范围:

1. singleton(default*)

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

2. prototype

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

3. request

Scopes a single bean definition to the lifecycle of a single HTTP request; that is each and every HTTP request will have 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.

4. session

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

5. 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.

*default 表示<bean /> 中没有明确提供范围。标签。在此处阅读有关它们的更多信息:http://static.springsource.org/spring/docs/3.0.0.M3/reference/html/ch04s04.html