Add property to MBeanExporter to control eager initiailization of FactoryBeans [SPR-4954]

[spring-projects-issues]

Scott Resnik opened SPR-4954 and commented

In spring 2.0, I was able to have the products of BeanFactory beans exported in JMX via the MBeanExporter. In spring 2.5, this is no longer the case. It appears that only the actual BeanFactory beans are exported (Noted with the "&" in the name). It appears this was done to avoid having the MBeanExporter eagerly init any BeanFactory beans.

It would be nice if in the autodetect method of the MBeanExporter the parameters to (line ~875 of MBeanExporter)"beanFactory.getNamesForType" call could be injected. Then the user would have control over whether or not the MBeanExporter causes eager initialization or not.

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Affects: 2.5.5

Issue Links:

• Lazy not honored when using MBeanExporter's autodetection (since 2.5) [SPR-4569] #9246 Lazy not honored when using MBeanExporter's autodetection (since 2.5)

[spring-projects-issues]

Juergen Hoeller commented

This is actually a side effect of #9246, done for Spring 2.5.3... We are avoiding lazy-init failures during type detection there: Lazy-init beans shouldn't be touched just for JMX exposure purposes. Unfortunately this also has the effect of ignoring FactoryBeans that haven't been initialized yet. Admittedly, it was never properly defined whether FactoryBean-exposed objects would be candidates for JMX exposure in the first place...

However, note that in case of a FactoryBean, it's that FactoryBean object that manages the lifecycle of the exposed reference. It's the FactoryBean object itself that receives configuration properties, init callbacks, destroy callbacks. Following that perspective, it should also be the FactoryBean object itself being exposed as an MBean... So I'm curious: what kind of MBean specifically are you exposing through a FactoryBean there?

Juergen

[spring-projects-issues]

Juergen Hoeller commented

I've added a corresponding "allowEagerInit" property to MBeanExporter, for autodetecting lazy-init beans and FactoryBean-produced objects. This will be available in tonight's 2.5.6 snapshot (http://static.springframework.org/downloads/nightly/snapshot-download.php?project=SPR). Please give it a try and let me know whether it works for you...

Juergen

[spring-projects-issues]

Scott Resnik commented

I'll give it a try tonight, or tomorrow morning and report back.

To answer your previous comment: We are exporting a spring managed quartz scheduler for the purpose of managing our quartz jobs. When we upgraded to spring 2.5.4/5 we were just getting the factory bean itself. I got around the issue by just passing a reference to the scheduler into the "beans" property on the exporter.