spring 中的scope 懂得
spring 中的scope 理解spring 中bean的scopesingleton默认的设置 适用于无状态的bean，以下设置是等价的be
spring 中的scope 理解
spring 中bean的scope
singleton 默认的设置 适用于无状态的bean，以下设置是等价的
<bean id="accountService" scope="singleton"/>
prototype 每次创建一个新的bean 适合有状态的bean
<bean id="accountService" scope="prototype"/>
Request, session, and global session 只有在web类型的ApplicationContext 工程中可用
例如XmlWebApplicationContext，以下是官方解释：
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.
