ResolvableType.isAssignableFrom() failure for raw types [SPR-11414]

[spring-projects-issues]

Jose Luis Martin opened SPR-11414 and commented

Hi all,

When upgrading to Spring 4.0.0 I noticed failures when autowiring raw types.

I think that should be expected that if some Service<?> service become autowired then a raw type declaration (Service service) should become autowired too.

I guess that it could be fixed checking for raw types in ResolvableType.getGenerics() and returning wildcards for all parameter types.

A proposal fix is in https://github.com/chelu/spring-framework/tree/resolvable-raw-types

Best regards,

Jose

---

Affects: 4.0 GA

Issue Links:

• Problem with autowiring of "generic Beans" (defined via RootBeanDefinition(s)) [SPR-11250] #15875 Problem with autowiring of "generic Beans" (defined via RootBeanDefinition(s))

[spring-projects-issues]

Juergen Hoeller commented

Have you been testing this against 4.0.0 (as stated in the text) or 4.0.1 (as stated in the "Affects Version" field)? Please do try 4.0.1 since there have been significant refinements to the type matching algorithm after 4.0 GA...

Juergen

[spring-projects-issues]

Jose Luis Martin commented

Hi Juergen,

Thanks for your attention,

I tested on current master branch. I just run the following test case now for ResolvableTypeTests
\

@Test
public void testRawTypes() throws Exception {
	ResolvableType rawList = ResolvableType.forField(Fields.class.getField("classType"));
	ResolvableType stringList = ResolvableType.forField(Fields.class.getField("stringList"));
	ResolvableType charSecuenceList = ResolvableType.forField(Fields.class.getField("charSequenceList"));
	ResolvableType stringListList = ResolvableType.forField(Fields.class.getField("stringListList"));
	ResolvableType listOfListOfUnknown = ResolvableType.forField(Fields.class.getField("listOfListOfUnknown"));
	
	assertAssignable(rawList, stringList, charSecuenceList, stringListList, listOfListOfUnknown)
				.equalTo(true, true, true, true);
}

And results on:
\

java.lang.AssertionError: java.util.List<?> isAssignableFrom java.util.List<java.lang.String>:java.util.List<java.lang.String>
Expected: <true>
     but: was <false>}}

[spring-projects-issues]

Juergen Hoeller commented

Ah, note that the raw type matching algorithm is not in ResolvableType, so those unit tests seem to be too specific. The raw type fallback algorithm is rather located in GenericTypeAwareAutowireCandidateResolver, as a second pass if no 'proper' generic type match has been found in the first pass.

ResolvableType itself remains with a clean generic type match algorithm, equivalent to what the Java compiler would accept as an assignment without any 'unchecked' warnings. The 'unchecked' part is effectively in GenericTypeAwareAutowireCandidateResolver, only kicking in as a fallback.

As a consequence, you'd have to test it with actual @Autowired usage which I suppose was your starting point anyway. This is what I would expect to pass against 4.0.1...

Hope that helps,

Juergen

[spring-projects-issues]

Jose Luis Martin commented

Hi Juergen

You're right, it works again in 4.0.1

Thanks for the clarification and sorry for the inconvenience.

[spring-projects-issues]

Juergen Hoeller commented

No worries. I'll mark this issue as "Won't Fix" then, since we have no plans to implement that algorithm in ResolvableType itself (which this issue's title suggests).

Juergen