How to collect and inject all beans of a given type in Spring XML configuration

Question

One of the strongest accents of the Spring framework is the Dependency Injection concept. I understand one of the advices behind that is to separate general high-level mecha

Answer 1

There's no out-of-the-box facility to do this, no. However, if you want a way of collecting all beans of a given type into a collection, without using an @Autowired list, then it's easy to write a custom FactoryBean to do it for you:

public class BeanListFactoryBean extends AbstractFactoryBean> {

    private Class beanType;
    private @Autowired ListableBeanFactory beanFactory;

    @Required
    public void setBeanType(Class beanType) {
        this.beanType = beanType;
    }

    @Override
    protected Collection createInstance() throws Exception {
        return beanFactory.getBeansOfType(beanType).values();
    }

    @Override
    public Class getObjectType() {
        return Collection.class;
    }    
}

and then

However, this all seems like a lot of effort to avoid putting @Autowired in your original class. It's not much of a violation of SoC, if it is at all - there's no compiltime dependency, and no knowledge of where the options are coming from.