Defining multiple @Named @Bean methods returning same type in a @Factory fails to inject with NonUniqueBeanException

[wetted]

named-factory-beans.zip

Task List

• Steps to reproduce provided
  See below
• Stacktrace (if present) provided
  Exception in thread "main" io.micronaut.context.exceptions.NonUniqueBeanException: Multiple possible bean candidates found: [named.factory.beans.Template, named.factory.beans.Template]
  at io.micronaut.context.DefaultBeanContext.findConcreteCandidate(DefaultBeanContext.java:1403)
  at io.micronaut.context.DefaultApplicationContext.findConcreteCandidate(DefaultApplicationContext.java:322)
  at io.micronaut.context.DefaultBeanContext.lastChanceResolve(DefaultBeanContext.java:1905)
  at io.micronaut.context.DefaultBeanContext.findConcreteCandidateNoCache(DefaultBeanContext.java:1846)
  at io.micronaut.context.DefaultBeanContext.lambda$findConcreteCandidate$50(DefaultBeanContext.java:1795)
  at io.micronaut.caffeine.cache.BoundedLocalCache.lambda$doComputeIfAbsent$14(BoundedLocalCache.java:2034)
  at java.util.concurrent.ConcurrentHashMap.compute(ConcurrentHashMap.java:1853)
  at io.micronaut.caffeine.cache.BoundedLocalCache.doComputeIfAbsent(BoundedLocalCache.java:2032)
  at io.micronaut.caffeine.cache.BoundedLocalCache.computeIfAbsent(BoundedLocalCache.java:2015)
  at io.micronaut.caffeine.cache.LocalCache.computeIfAbsent(LocalCache.java:113)
  at io.micronaut.caffeine.cache.LocalManualCache.get(LocalManualCache.java:54)
  at io.micronaut.context.DefaultBeanContext.findConcreteCandidate(DefaultBeanContext.java:1794)
  at io.micronaut.context.DefaultBeanContext.getBeanInternal(DefaultBeanContext.java:1590)
  at io.micronaut.context.DefaultBeanContext.getBean(DefaultBeanContext.java:512)
  at io.micronaut.context.UnresolvedProvider.get(UnresolvedProvider.java:47)
  at named.factory.beans.ApplicationHelper.getTemplate(ApplicationHelper.java:15)
  at named.factory.beans.Application.main(Application.java:9)
• Example that reproduces the problem uploaded to Github
  See attached
• Full description of the issue provided (see below)

Steps to Reproduce

1. create a Factory class
2. create two or more Bean methods using Named qualifiers that all return the same type
3. create a test or client class that injects one of those beans, qualified by Named value

Expected Behavior

The named bean should be injected as expected. I have also tried same type of injection in a test (@MicronautTest)

Actual Behavior

Fails with exception NonUniqueBeanException (as if I didn't qualify the beans)

Environment Information

• Operating System: Mac Mojave/Windows 10
• Micronaut Version: 1.0.3 + Micronaut Test 1.0.1
• JDK Version: 1.8

Example Application

named-factory-beans.zip

• TODO: link to github repository with example that reproduces the issue

[brianwyka]

Also saw this issue. Here is some example source:

Factory class:

@Factory
public class CaffeineCacheFactory {
    
    @Bean
    @Singleton
    @Named("orgRepositoryCache")
    public Cache<String, Flowable<GitRepository>> orgRepositoryCache() {
        return Caffeine.newBuilder()
                .maximumSize(20)
                .expireAfterWrite(30, TimeUnit.DAYS)
                .build();
    }

    @Bean
    @Singleton
    @Named("repositoryCache")
    public Cache<String, Maybe<GitRepository>> repositoryCache() {
        return Caffeine.newBuilder()
                .maximumSize(20)
                .expireAfterWrite(30, TimeUnit.DAYS)
                .build();
    }

}

Service class using constructor injection:

@Singleton
public class GithubRepositoryService {

   private final Cache<String, Flowable<GitRepository>> orgRepositoryCache;
   private final Cache<String, Maybe<GitRepository>> repositoryCache;

   public GithubRepositoryService(@Named("orgRepositoryCache") Cache<String, Flowable<GitRepository>> orgRepositoryCache, @Named("repositoryCache") Cache<String, Maybe<GitRepository>> repositoryCache) {
      this.orgRepositoryCache = orgRepositoryCache;
      this.repositoryCache = repositoryCache;
   }

    public Flowable<GitRepository> fetchRepositories(final String org) {
        return orgRepositoryCache.get(org, cacheKey -> githubApiClient.getRepositories(cacheKey).cast(GitRepository.class).cache());
    }

    public Maybe<GitRepository> fetchRepository(final String org, final String name) {
        return repositoryCache.get(org + "/" + name, cacheKey -> githubApiClient.getRepository(org, name).cast(GitRepository.class).cache());
    }

...

}

[brianwyka]

Can we have a feature request to (similarly to Spring) name the bean after the method in the factory class?

[graemerocher]

@brianwyka potentially, Micronaut is different from Spring however in that bean names are not unique. You can have 2 beans of different types with the same name. In that sense the name is the qualifier rather than the name. We didn't want to do the same as Spring because that would maybe cause the expectation that Micronaut behaves the same way which it does not.

[graemerocher]

@brianwyka FWIW I added a test for your example and it works fine 0b980e7

What didn't work is Provider instances with qualifiers, which is resolved with 3e74d69

[brianwyka]

Thanks for the explanation @graemerocher