gcalex5 gcalex5 - 2 months ago 16
Java Question

Spring Bean Scopes

Can someone explain what the scopes are in Spring beans I've always just used 'prototype' but are there other parameters I can put in place of that?

Example of what I'm talking about

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

Answer

From the spring specs, there are five types of bean scopes supported :

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 means when no scope is explicitly provided in the <bean /> tag. read more about them here: http://static.springsource.org/spring/docs/3.0.0.M3/reference/html/ch04s04.html

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