Allow setting custom ClassPathBeanDefinitionScanner on AnnotationConfigWebApplicationContext [SPR-9324]

[spring-projects-issues]

Richard L. Allen opened SPR-9324 and commented

We use a custom ClassPathBeanDefinitionScanner along with AnnotationConfigWebApplicationContext. To achieve this, we have to extend AnnotationConfigWebApplicationContext and override the loadBeanDefinitions method to substitute our custom scanner. Would be nice if AnnotationConfigWebApplicationContext simply had a set method for the scanner the same as the set methods for the BeanNameGenerator and ScopeMetadataResolver.

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Affects: 3.1.1

Referenced from: commits 0230c49, 20beace

Backported to: 4.1.9

1 votes, 1 watchers

[spring-projects-issues]

Chris Beams commented

Hi Richard,

I see what you mean - overriding ACWAC#loadBeanDefinitions does represent quite a bit of code duplication.

On the other hand, providing a #setClassPathBeanDefinitionScanner method isn't ideal either. First, it's adding a public method for what is almost certainly a very uncommon use case; second, the scanner requires the BeanFactory at construction time, and this is not yet available.

As a compromise, I would consider a pull request that introduces protected methods with the following signatures:

protected ClassPathBeanDefinitionScanner getClassPathBeanDefinitionScanner(BeanDefinitionRegistry registry);

protected AnnotatedBeanDefinitionReader getAnnotatedBeanDefinitionReader(BeanDefinitionRegistry registry);

The default implementations of these methods would be simply to return new CPBDS(registry) and new ABDR(registry) respectively. But they would also of course allow you to override exactly the methods you need instead of the entirety of #loadBeanDefinitions.

You can find out more about issuing pull requests by reading the contributor guidelines.

Thanks!

[spring-projects-issues]

Val Blant commented

I would really like to see this feature as well!

We need to override the way ClassPathBeanDefinitionScanner resolves beanName conflicts, which is an extremely simple change to the checkCandidate() method, but there is no way to plug in a different Scanner cleanly.