Q:

Where are valid values defined for @Scope in web-aware and portal spring contexts?

The following allows the declaration of a singleton bean in Spring 3.0:
@Bean
@Scope(BeanDefinition.SCOPE_SINGLETON)
private void setBean1(Bean1 b1) {
    this.b1 = b1;
}

But, BeanDefinition does not define scopes values for request, session and global session. Where are these defined? Else, should I use @Scope("request"), @Scope("session") and @Scope("global session")?

A:

You can use string literals if you want (though global session would be "globalSession").
Alternatively, you can use constants defined in WebApplicationContext.

A:

BeanDefinition only has SCOPE_SINGLETON and SCOPE_PROTOTYPE.  
The other scopes, being only applicable to web applications, are defined in org.springframework.web.context.WebApplicationContext.
A useful list of constants can be found in the javadoc for Constant Field values.

