How to define which implementation to execute?

If I have more than 2 implementations of DAO how to define in ServiceImpl that, which implementation should execute when run the program in Spring BOOT?

>Solution :

You can use @Qualifier annotation in this case along with @Autowired if you want to specify which bean you want to use.

for eg:-

@Qualifier("Dao1")
@Autowired
private final Dao daoImpl1;

This will make sure that the bean or Dao bean with name Dao1 will only be injected so that you can use it .

You can learn more about this from the below post:

https://www.baeldung.com/spring-qualifier-annotation