When the @Primary annotation is used on a bean, it becomes the primary one to be used when there is more than one candidate available to autowire a specific dependency.
In the case of the following example , there are two sorting algorithms available: QuickSort and MergeSort. If the component scan finds both of them, QuickSort is used to wire any dependencies on SortingAlgorithm because of the @Primary annotation:
interface SortingAlgorithm { } @Component class MergeSort implements SortingAlgorithm { // Class code here } @Component @Primary class QuickSort implements SortingAlgorithm { // Class code here }
