Jave EE usage of @qualifier #- create type enum #- create qualifier annotation #- create service interface #- create implementations of service interface #- inject and use qualifier annotation to specify the correct service

EProductivityPlanType.java

public enum EProductivityPlanType {
    TARGET, ACTUAL
}

IProductivityPlan.java

public interface IProductivityPlan {
     void calculate();
}

ProductivityPlanActual.java

@ProductivityPlanType(type = EProductivityPlanType.ACTUAL)
public class ProductivityPlanActual implements IProductivityPlan {
    @Override
    public void calculate() {
        // calculate actual productivity plan
    }
}

ProductivityPlanTarget.java

@ProductivityPlanType(type = EProductivityPlanType.TARGET)
public class ProductivityPlanTarget implements IProductivityPlan {
    @Override
    public void calculate() {
        // calculate target productivity plan
    }
}

ProductivityPlanType.java

@Qualifier
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD, ElementType.PARAMETER})
public @interface ProductivityPlanType {
    EProductivityPlanType type() default EProductivityPlanType.TARGET;
}

Usage.java

...

@Inject
@ProductivityPlanType(type = EProductivityPlanType.TARGET)
private IProductivityPlan productivityPlanTarget;

@Inject
@ProductivityPlanType(type = EProductivityPlanType.ACTUAL)
private IProductivityPlan productivityPlanActual;

...