@Qualifier Annotation in Java

There may be a case when you want to create more than one bean of the same Class and want to autowire only one of them with a property. In such cases, you can use the @Qualifier annotation along with @Autowired annotation.

By doing this you will eliminate the confusion as to which bean would be autowired to that property.

Consider the below bean configuration in the xml file.

   <bean id = "emp1" class = "com.springsamples.Employee">
      <property name = "name" value = "John" />
      <property name = "age" value = "30"/>
   </bean>

   <bean id = "emp2" class = "com.springsamples.Employee">
      <property name = "name" value = "David" />
      <property name = "age" value = "40"/>
   </bean>

   <bean id = "emp3" class = "com.springsamples.Employee">
      <property name = "name" value = "Neil" />
      <property name = "age" value = "35"/>
   </bean>

You will see 3 bean objects from the employee class. If you try to autowire an Employee property using @Autowired annotation as below, it would fail as auto wiring would be done basis type and there are 3 candidates for the same.

@Autowired

private Employee emp;

To solve this, we would use the @Qualifier annotation as below.

@Component
public class People {
   @Autowired
   @Qualifier("emp1")
   private Employee emp;

}

Here emp property would be auto wired with the bean of the Employee class having bean id emp1.

Tag: @Qualifier Annotation in Java

@Qualifier Annotation in Spring