Spring接口注入示例

public interface PersonInterface {
    void greet();
}

public class PersonImplementation implements PersonInterface {
    @Override
    public void greet() {
        System.out.println("Hello, I'm the PersonImplementation!");
    }
}

import org.springframework.beans.factory.ObjectFactory;
import org.springframework.beans.factory.annotation.Autowired;

public class PersonFactory implements ObjectFactory<PersonInterface> {
    @Autowired
    private PersonImplementation personImplementation;

    @Override
    public PersonInterface getObject() throws Exception {
        return personImplementation;
    }

    @Override
    public Class<?> getObjectType() {
        return PersonImplementation.class;
    }
}

@Controller
public class PersonController {
    @Autowired
    private PersonInterface person;

    @RequestMapping("/person")
    public String greet() {
        person.greet();
        return "forward:/";
    }
}

$ mvn spring-boot:run
$ curl -X GET http://localhost:8080/person
Hello, I'm the PersonImplementation!