Spring Autowire retrieves the wrong class

Question

I have

public abstract class AbstractClass<T> {
  public abstract MyStatus getStatus();
  public void test() {
     System.out.println(getStatus().testField());
  }
}

for Dogs I have

@Component("dogs")
public class Dogs extends AbstractClass<Dogs>{
   @Autowired
   MyStatus statusField;

   @PostConstruct
   private void init() {
      statusField.setTest("dogs");
   }

   public getStatus() {
     return statusField;
   }
}

for cats I have

@Component("cats")
public class Cats extends AbstractClass<Cats>{
   @Autowired
   MyStatus statusField;

   @PostConstruct
   private void init() {
      statusField.setTest("cats");
   }

   public getStatus() {
     return statusField;
   }
}

and for the StatusContainer I have

@Component
@Data
public class MyStatus<T> {
   public String test; // and other options from the application.properties file
}

I would expect that if I @Autowired Dogs I get for the status field dogs and for the Cats I'll get cats .

public class ClassA {
   @Autowired
   @Qualifier("dogs")
   Dogs myDogEntity;
}

public class ClassB {
   @Autowired
   @Qualifier("cats")
   Cats myCatEntity;
}

Matter of fact is that if I print the information of MyStatus I get everytime cats (or everytime dogs ). I would have exptected that the container is initiated differently and injected with the appropriate instance. But thats not true.

Is there a simple way to have separete containers for different objects instead of injecting the same?

UPDATE Unfortunately I have had some typos in my orginal code. Fixed them - hopefully all.

I finally figured out that the major problem is/was that Spring creates only one instance of a component. In my case MyStatus . Consequently this one instance is injected into the other classes. Any manipulation on this one class will lead to the side effect that it manipulates the other.

My solution: Split the config into two parts - one which is Spring related and one the instance, eg Cats or Dogs will handle indiviudally - without Spring (injection)!!!

Answer 1

Your problem is that by default, the scope is Singleton on Spring and you end up having the same instance of MyStatus in both Dogs and Cats.

There is a simple way of achieving this, for the class MyStatus, you can set the scope to Prototype:

@Data
@Component
@Scope(value = ConfigurableBeanFactory.SCOPE_PROTOTYPE)
public class MyStatus<T> {
   public String test; 
}

This way, you don't need to change anything else. Because Spring will create a new instance for everybody that requests to inject it.

This way, the classes Cats and Dogs will have different instances of MyStatus.

Answer 2

You have to update your code and correct the Typing mistakes, I've posted below with correction.

public class ClassA {
   @Autowired
   @Qualifier("dogs")
   Dogs myDogEntity;
}

public class ClassB {
   @Autowired
   @Qualifier("cats")
   Cats myCatEntity;
}