The @Qualifier annotation can be used to give a reference to a Spring bean. The reference can be used to qualify the dependency that needs to be autowired.
In the case of the following example, there are two sorting algorithms available: QuickSort and MergeSort. But since @Qualifier("mergesort") is used in the SomeService class, MergeSort, which also has a mergesort qualifier defined on it, becomes the candidate dependency selected for autowiring:
@Component @Qualifier("mergesort") class MergeSort implements SortingAlgorithm { // Class code here } @Component class QuickSort implements SortingAlgorithm { // Class code here } @Component class SomeService { @Autowired @Qualifier("mergesort") SortingAlgorithm ...
