eMexo Technologies- In Spring, bean scope is used to decide which type of bean instance should be return from Spring container back to the caller.
- Singleton [Default]
- Only one instance of bean per spring IOC container
- Prototype
- A new instance every time bean is requested
- Request [Web Application Related]
- Single bean instance per HTTP request
- Essentially these are available through web aware application context (e.g. WebApplicationContext)
- Session [Web Application Related]
- Single bean instance per HTTP session
- Essentially these are available through web aware application context (e.g. WebApplicationContext)
- Global session [Web Application Related]
- Single bean instance per global HTTP session
- Essentially these are available through web aware application context (e.g. WebApplicationContext)
- Global-session is a little different in sense that it is used when application is portlet based. In portlets, there will be many applications inside a big application and a bean with scope of ‘global-session’ will have only one instance for a global user session.
Example – In Bean Configuration File
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> <bean id="demoBean" class="com.emexo.application.web.DemoBean" scope="session" /> </beans>
Example – Using Annotations
@Service
@Scope("session")
public class DemoBean
{
//Some code
}