《Spring Recipes》第二章筆記：Setting Bean Scopes

《Spring Recipes》第二章筆記：Setting Bean Scopes

問題

Spring容器默認建立的bean都是單例。

解決方案

Spring容器的<bean>元素的scope屬性指定了bean的scope。

Table 4.3. 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.

例：

<bean id="shoppingCart" class="com.apress.springrecipes.shop.ShoppingCart"
scope="prototype" />