弹簧靴扫描并注入外部非弹簧豆

Question

What does it take, or is it even possible for Spring to scan and inject non-spring annotated classes? For example.

resource.jar

com.project.resource.ResourceInterface
com.project.resource.StandardResource <-- concrete implementation

@Singleton <--- Standard CDI annotation
public class StandardResource implements ResourceInterface{
    @Override
    public void something(){}
}

Now let's say I have a spring boot application which depends on resource.jar .

com.project.resource.SpringApp

@SpringBootApplication(scanBasePackages = {"com.project"})
@EnableAutoConfiguration
public class SpringApp{
    ... initializer
    @Inject
    private ResourceInterface resourceService; <--- this is not found
}

Is this supposed to work out of the box? Is this even possible? I'm using spring boot 2.0.0.RELEASE . I'm getting the following error:

Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'MainController': Unsatisfied dependency expressed through field 'resourceService'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.project.resource.ResourceInterface' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@javax.inject.Inject()}

Thanks

Answer 1

For Spring framework @Singleton has no meaning, as such even if class is picked up by component scanning it's going to be ignored. In order for Spring to recognize your class you can:

• Create a configuration class in com.project.resource with @Bean of
  ResourceInterface and instantiate it as StandardResource .
• Since you are using Spring Boot you can create Auto-configuration (which will be similar to the first option) in resource.jar. You can follow examples from creating autoconfiguration . With this approach no changes needed in com.project.resource

After that your spring boot app will run normally