@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Tag{
    String code();
    
    String name() default "";
}

public class TagImpl implements Tag{
     
    private final String code;

    private final String name;

    public TagImpl(String code, String name) {
        this.code = code;
        this.name = name;
    }

    public TagImpl(String code) {
        this.code = code;
        this.name = "";
    }

    @Override
    public String code() {
        return code;
    }

    @Override
    public String name() {
        return name;
    }

    @Override
    public Class<? extends Annotation> annotationType() {
        return Tag.class;
    }


    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        boolean son = o instanceof Tag;
        if (!son) {
            return false;
        }
        Tag that = (Tag) o;
        return Objects.equals(code, that.code()) ;
    }

    @Override
    public int hashCode() {
        return (127 * "code".hashCode()) ^ code.hashCode();
    }
}

public interface Api{
    
    void execute();
    
}

@Tag(code = "Def")
public class DefaultApi implements Api{
    
    public void execute(){
        
    }
    
}

public class ApiManager{
    
    private static final Map<Tag,Api> apiStore = new HashMap<>();
    
    public static void addApi(Api api){
        Tag tag = api.getClass().getAnnotation(Tag.class);
        apiStore.put(tag,api);
    }
    
    public static Api getApi(String code){
        TagImpl tag = new TagImpl(code);
        apiStore.get(tag);
    }
}