Autowiring of beans in spring boot with #Qualifier annotation - spring

Question

I am learning autowiring in Spring Boot using #Primary and #Qualifier annotations. I am able to understand that #Primary wires the annotated class as a dependency and in case more than one satisfying classes are found #Qualifier can come to help.
#Component
public class VehicleBean {
#Autowired
#Qualifier("car")
Vehicle car;
public void check() {
car.details();
}
public Vehicle getCar() {
return car;
}
public void setCar(Vehicle car) {
this.car = car;
}
}
Bike
#Component
//#Primary
#Qualifier("car")
public class Bike implements Vehicle {
#Override
public void details() {
System.out.println("Bike is driving");
}
}
Car
#Component
//#Primary
#Qualifier("bike")
public class Car implements Vehicle {
#Override
public void details() {
System.out.println("Car is driving");
}
}
When I add #Qualifier("car") on my autowired dependency named as "bike" and have #Qualifier("car") on Car and #Qualifier("bike") on Bike, it picks up Car. However, when I interchange the #Qualifier on Bike and Car(e.g - #Qualifier("bike") on Car and vice versa) it picks up the bike. Also when I change the #Qualifier to "bike on my autowired dependency named as "car" and have #Qualifier("car") on Bike and vice verse, it is picking Car. I was expecting Bike to be picked. What am I missing?

Answer 1

The use of qualifier annotation here is incorrect, the qualifier annotation is used on a field, a parameter or a method to pick the write candidate bean while authowiring,
This annotation may be used on a field or parameter as a qualifier for
candidate beans when autowiring. (JAVA DOC)
In simple word, you define the beans by name and you tell spring what name to pick by adding #Qualifier, in your example you have to add the bean name in #Component.
#Component("bike")
public class Bike implements Vehicle {
#Override
public void details() {
System.out.println("Bike is driving");
}
}
#Component("car")
public class Car implements Vehicle {
#Override
public void details() {
System.out.println("Car is driving");
}
}
Coming to your question, why it picks Car? , because the AnnotationBeanNameGenerator generate a default name if no one specified and the built name is based on the short name of the class (with the first letter lower-cased):
If the annotation's value doesn't indicate a bean name, an appropriate
name will be built based on the short name of the class (with the
first letter lower-cased). For example:
com.xyz.FooServiceImpl -> fooServiceImpl (JAVA DOC)

Answer 2

#Qualifier annotation won't work here #Component #Qualifier("car"). It can be used on a field, a parameter or a method for autowiring.
You need to pass the name with #Component annotation only, like #Component("car")