Add suport for ManagedList and ManagedSet

[abuijze]

In one of my beans, I rely on a list of other bean instances to be injected. The items in the list can be of any type, so it's practically defined as a List<Object>.
A BeanDefinitionRegistryPostProcessor generates the BeanDefinition for that bean. I use a ManageList containing RuntimeBeanNameReferences (but tried other BeanReference implementations too) to refer to the beans that I need to be injected.

Without Spring AOT, this works perfectly. The injected value is indeed a list of actual bean instances.
When running Spring AOT, however, the injected value is a List of RuntimeBeanNameReference.

In the ContextBootstrapInitializer, the AOT plugin generates the following code for the bean:

    BeanDefinitionRegistrar.of("MessageHandlerConfigurer$$Axon", MessageHandlerConfigurer.class).withConstructor(List.class)
        .instanceSupplier((instanceContext) -> instanceContext.create(beanFactory, (attributes) -> new MessageHandlerConfigurer(attributes.get(0)))).customize((bd) -> bd.getConstructorArgumentValues().addIndexedArgumentValue(0, List.of(new RuntimeBeanReference("myEventHandler"), new RuntimeBeanReference("mySecondEventHandler")))).register(beanFactory);

The relevant part:

.customize((bd) -> bd.getConstructorArgumentValues()
                     .addIndexedArgumentValue(0, 
                                              List.of(new RuntimeBeanReference("myEventHandler"), 
                                                      new RuntimeBeanReference("mySecondEventHandler"))))

When I change that manually to

    BeanDefinitionRegistrar.of("MessageHandlerConfigurer$$Axon", MessageHandlerConfigurer.class).withConstructor(List.class)
                           .instanceSupplier((instanceContext) -> instanceContext.create(beanFactory, (attributes) -> new MessageHandlerConfigurer(attributes.get(0))))
                           .customize((bd) -> {
                             var list = new ManagedList<>();
                             list.addAll(List.of(new RuntimeBeanReference("myEventHandler"), new RuntimeBeanReference("mySecondEventHandler")));
                             bd.getConstructorArgumentValues().addIndexedArgumentValue(0, list);
                                                        }).register(beanFactory);

Everything works as expected.

Do I need to configure something differently, or should the generated ContextBootstrapInitializer use a ManageList as a container for collections that contain a BeanReference?

[snicoll]

@abuijze thanks for the report and the sample. AOT doesn't support ManagedList yet, I'll see what I can do.

[snicoll]

@abuijze if you have the cycles to give Spring Native 0.11.3-SNAPSHOT a try, I would really appreciate it.

[abuijze]

The generated AOT file now generates a compiler error (on OpenJDK 11.0.12)

[ERROR] Failed to execute goal org.springframework.experimental:spring-aot-maven-plugin:0.11.3-SNAPSHOT:generate (generate) on project native-axon-demo: Build failed during Spring AOT code generation: Unable to execute mojo: Compilation failure:
[ERROR] /native-axon-demo/target/generated-runtime-sources/spring-aot/src/main/java/org/springframework/aot/ContextBootstrapInitializer.java:[398,112] incompatible types: inference variable R has incompatible bounds
[ERROR]     lower bounds: org.springframework.beans.factory.config.ConstructorArgumentValues.ValueHolder,java.util.Collection<T>,java.lang.Object
[ERROR]     lower bounds: org.springframework.beans.factory.support.ManagedList<E>
[ERROR] /native-axon-demo/target/generated-runtime-sources/spring-aot/src/main/java/org/springframework/aot/ContextBootstrapInitializer.java:[404,160] incompatible types: inference variable R has incompatible bounds
[ERROR]     lower bounds: org.springframework.beans.factory.config.ConstructorArgumentValues.ValueHolder,java.util.Collection<T>,java.lang.Object
[ERROR]     lower bounds: org.springframework.beans.factory.support.ManagedList<E>
[ERROR] /native-axon-demo/target/generated-runtime-sources/spring-aot/src/main/java/org/springframework/aot/ContextBootstrapInitializer.java:[410,110] incompatible types: inference variable R has incompatible bounds
[ERROR]     lower bounds: org.springframework.beans.factory.config.ConstructorArgumentValues.ValueHolder,java.util.Collection<T>,java.lang.Object
[ERROR]     lower bounds: org.springframework.beans.factory.support.ManagedList<E>
[ERROR] -> [Help 1]
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[abuijze]

fyi, the code it generates is:

    BeanDefinitionRegistrar.of("MessageHandlerConfigurer$$Axon$$COMMAND", MessageHandlerConfigurer.class).withConstructor(MessageHandlerConfigurer.Type.class, List.class)
        .instanceSupplier((instanceContext) -> instanceContext.create(beanFactory, (attributes) -> new MessageHandlerConfigurer(attributes.get(0), attributes.get(1)))).customize((bd) -> {
      ConstructorArgumentValues argumentValues = bd.getConstructorArgumentValues();
      argumentValues.addIndexedArgumentValue(0, "COMMAND");
      argumentValues.addIndexedArgumentValue(1, Stream.of(new RuntimeBeanReference("myCommandHandler")).collect(Collectors.toCollection(ManagedList::new)));
    }).register(beanFactory);

Which looks correct to me...

[snicoll]

Ah damn. That works on Java 17 but not 11 I suspect.

[abuijze]

Running it on OpenJDK 17.0.2 gives me the same compiler error.

[snicoll]

🤦

[snicoll]

The code is correct but the compiler is unable to infer the type unless the value is assigned unfortunately. This is due to the overloaded addIndexedArgumentValue that takes a ValueHolder.

[snicoll]

The data-elasticsearch sample also failed as a result. I've reverted for now and will research another solution for this.

[abuijze]

What if you explicitly use the public void addIndexedArgumentValue(int index, @Nullable Object value, String type) method? Looks like null is the default used for type. Adding that should avoid confusion with the overloaded methods.

[snicoll]

Nope. There are many other places where such an inference can go wrong. That code is generic and not specific to this particular feature.