CDI producers are another Java EE feature that is especially helpful to realize factories of all kinds of sorts. The producers, mostly realized as producer methods, provide the object that can be injected in other managed beans. This decouples creation and configuration logic from the usage. Producers are helpful when custom types other than managed bean types need to be injected.

The following shows the definition of a CDI producer method:

import javax.enterprise.inject.Produces;

public class CarFactoryProducer {

    @Produces
    public CarFactory exposeCarFactory() {
        CarFactory factory = new BMWCarFactory();
        // use custom logic
        return factory;
    }
}

The exposed CarFactory type can simply be injected using @Inject, as seen previously in the CarManufacturer example. CDI invokes the exposeCarFactory() method once a CarFactory instance is required and inserts the returned object into the injection point.

These techniques already cover most of the requirements for the core domain logic use cases.