Spring IOC bean的生存周期scope范围

?

a)?????singleton?单例(默认)

b)?????proptotype?每次创建新的对象

Bean scopes

ScopeDescription

singleton

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 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.

session

Scopes a single bean definition to the lifecycle of a 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.

?request、session、global session 在web中才起效，比如和struts集成但很少用，struts中可以很方便访问request等?<bean id="userService" ref="u" />
????-->
????<constructor-arg>
?????<ref bean="u"/>
????</constructor-arg>
??</bean>?UserService service = (UserService)ctx.getBean("userService");
UserService service2 = (UserService)ctx.getBean("userService");
??System.out.println(service == service2); //false??如果scope="singleton"，则是单例，为true