Could not instantiate bean class: Specified class is an interface

Question

I know there are threads similar to this issue. Below is my class and I am configuring it in spring.xml file. Actually HumanResourceService is an interface having only one method.

@Endpoint
public class HolidayEndpoint {

    @Autowired
    private HumanResourceService humanResourceService;

    @Autowired
    public HolidayEndpoint(HumanResourceService humanResourceService) throws JDOMException {
        this.humanResourceService = humanResourceService;
    }
}

My problem is that in my spring.xml file, when I define HumanResourceService as bean, it cannot be instantiated as this is an interface. How can I mention an interface in spring configuration file. My spring.xml file is below

<bean id="holidayEndpoint" class="com.mycompany.hr.ws.HolidayEndpoint" autowire="constructor" >
     <property name="humanResourceService" ref="humanResourceService" />
</bean>
<bean id="humanResourceService" class="com.mycompany.hr.service.HumanResourceService" />

Answer 1

You can't, Spring needs something it can make an instance from, the interface isn't enough.

In your spring.xml, the value of the class attribute for your bean with id="humanResourceService" should be the name of your implementation class, not the interface. Spring needs you to tell it what implementation class you want it to use for this.