MockHttpServletResponse.getHeaderNames is incompatible with Servlet 3.0 [SPR-9885]

[spring-projects-issues]

Joshua Spiewak opened SPR-9885 and commented

HttpServletResponse defines getHeaderNames as returning Collection<String>, while MockHttpServletResponse defines it as returning Set<String>.
Use of the interface with a concrete instance of the mock yields an AbstractMethodError.
Attached are a Maven pom.xml and Java class that compiles but when run yields the exception:

Exception in thread "main" java.lang.AbstractMethodError: org.springframework.mock.web.MockHttpServletResponse.getHeaderNames()Ljava/util/Collection;
	at Example.main(Example.java:9)

The closest existing issue that I could find is #13173 which covered getHeaders but not getHeaderNames.

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Affects: 3.1.2

Attachments:

• Example.java (406 bytes)
• pom.xml (1014 bytes)

Referenced from: commits f9bb4b3, 5a773b7

Backported to: 3.1.4

0 votes, 5 watchers

[spring-projects-issues]

Chris Beams commented

Rossen, could you take a look at this with an eye toward 3.1.3? We can discuss if you like.

[spring-projects-issues]

Juergen Hoeller commented

Good point, this is indeed incompatible at runtime. The compiler swallows it even when actually compiled against the Servlet 3.0 API, so I'm not sure why we see failure at runtime here...

In any case, I've changed the signature to Collection in order for this to be consistent.

Juergen

[spring-projects-issues]

Jeffrey Segal commented

It appears that this was re-introduced in 3.2.1.RELEASE. I see it in my app for 3.2.1 and 3.2.2, but not 3.2.0. I'm using:

<dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-test-mvc</artifactId>
     <version>1.0.0.BUILD-SNAPSHOT</version>
     <scope>test</scope>
</dependency>