Spring | Autowiring Qualifier

Spring provides @Qualifier annotation to refer correct bean while doing autowiring.

Suppose we have interface IService which has two concrete implementation.

When we try to Autowire IService object in any other class it will throw exception as there are two beans.

Spring Qualifier is used in such situation to place object of correct implementation class to autowired object.

 

	public interface IService {
	doSomething();
	}
	@Component("iServiceImplOne")
	public class IServiceImplOne implements IService {
	doSomething() {
	//some code
	}
	}
	@Component("iServiceImplTwo")
	public class IServiceImplTwo implements IService {
	doSomething() {
	//some code
	}
	}
	@Component("someClass")
	public class SomeClass {
	@Autowire
	private IService iservice;
	//some other code
	}
	@Component("someClass")
	public class SomeClass {
	@Autowire
	@Qualifier("iServiceImplTwo")
	private IService iservice;
	//some other code
	}

view raw SpringQualifierAutoWire.java hosted with ❤ by GitHub

Now, above iservice object will hold object of IServiceImplTwo class.