Annotation based injection into non public base classes does not work [SPR-7900]

[spring-projects-issues]

Andreas Benneke opened SPR-7900 and commented

Annotation driven injection on public methods specified in a non-public base classes does not work, because Java generates bridge methods for the subclass which are not ignored by Spring (as they should IMHO).

Example:

/* not public! */ class Base {

	@Resource
	public void setResource(Injectable injectable) {
           ...
	}
}

@Component
public class Target extends Base {

}

Same applies to @Autowired.

The attached maven project demonstrates this.

Workarounds: Use field injection, re-declare the method(s) in the subclass or make the base class public.

---

Affects: 3.0.5

Attachments:

• injection-test.zip (3.10 kB)
• mylyn-context.zip (4.65 kB)

Issue Links:

• AutowiredAnnotationBeanPostProcessor should ignore bridge methods when looking for annotations [SPR-8434] #13080 AutowiredAnnotationBeanPostProcessor should ignore bridge methods when looking for annotations ("is duplicated by")
• Bridged method detection leads to false positive detection of autowired annotations [SPR-8660] #13302 Bridged method detection leads to false positive detection of autowired annotations
• @Resource injection broken under spring-framework > 4.1.0 [SPR-12490] #17096 @Resource injection broken under spring-framework > 4.1.0
• Consistent bridge method handling in annotation post-processors [SPR-12495] #17101 Consistent bridge method handling in annotation post-processors

[spring-projects-issues]

Stefan Gybas commented

This used to work on Java 5. I have created another issue (#13080) because I did not find this issue in my first search.

[spring-projects-issues]

Chris Beams commented

Andreas,

Thanks for the test project. I'm reproducing this locally and we'll definitely patch things up here. Scheduling for inclusion in 3.0.6 as well as 3.1 RC1 as the fix will likely be worth backporting.

[spring-projects-issues]

Chris Beams commented

Author: Chris Beams <cbeams@vmware.com>
Date:   Tue Jun 21 22:23:54 2011 +0800

    Fix bridge method detection for class hierarchies
    
    Prior to this change, @Autowired injection against an instance of a
    subclass having different visibility than its superclass would fail
    if the @Autowired method is declared only in the superclass. This is due
    to an apparent change in the rules around bridge method generation
    between Java 5 and Java 6, and possibly even varying across compiler
    vendors.
    
    Now, BridgeMethodResolver is used consistently when detecting
    @Autowired, @Inject and @Resource metadata to bypass these bridge
    methods if they exist.
    
    Issue: SPR-7900