Spring beans in singleton scope are ignoring default component-scan scoped-proxy configuration [SPR-6683]

[spring-projects-issues]

Mauricio Noda opened SPR-6683 and commented

<context:component-scan base-package="somePackage" scoped-proxy="targetClass" />

It doesn´t matter what is configured in the scoped-proxy attribute, singleton scoped beans defaults to "no" and they have to be all configured explicity in a one-by-one basis using @Scope(proxyMode = TARGET_CLASS).

It generates a lot of annoying java.io.NotSerializableException in common web applications until all singletons are found and have their proxyMode attribute set.

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Affects: 3.0 GA

Referenced from: commits abdc35c, 56d2c9d

[spring-projects-issues]

Juergen Hoeller commented

There is a backwards compatibility problem hiding here: In Spring 2.5, we had scoped proxies technically only working for non-singleton beans (that aside, the containing BeanFactory wasn't serializable, so singleton beans couldn't actually benefit from a scoped proxy).

For Spring 3.0(.1), I opted for a compromise now: Component classes which are explicitly annotated with @Scope("singleton") - or custom scope annotations which happen to be meta-annotated with @Scope("singleton") - are eligible for component-scan's scoped-proxy setting. After all, their scope annotation indicates ScopedProxyMode.DEFAULT since Spring 3.0 and hence suggests the use of component-scan's setting. However, component classes with no scope annotations at all do still not qualify: They will be defaulted to singletons but will never receive a scoped proxy.

Juergen

[spring-projects-issues]

Mauricio Noda commented

This issue should have been reported earlier, before Spring 3.0.0 was released. Then compatibility would less of an issue.

Thanks anyway.