Spring 3-在运行时基于另一个对象属性的动态自动装配

我的解决方案如下：

VehicleDao接口中的isResponsibleFor方法：

interface VehicleDao {    public boolean isResponsibleFor(Vehicle vehicle);}

示例实现：

@Repositoryclass CarDAO implements VehicleDAO {    public boolean isResponsibleFor(Vehicle vehicle) {        return "CAR".equals(vehicle.getType());    }}

然后自动连接VehicleService中所有VehicleDao实现的列表：

public class VehicleServiceImpl implements VehicleService {    @Autowired    private List<VehicleDao> vehicleDaos;    private VehicleDao daoForVehicle(Vehicle vehicle) {         foreach(VehicleDao vehicleDao : vehicleDaos) {   if(vehicleDao.isResponsibleFor(vehicle) {        return vehicleDao;   }         }         throw new UnsupportedOperationException("unsupported vehicleType");    }    @Transactional    public void save(Vehicle vehicle) {         daoForVehicle(vehicle).save(vehicle);    }}

这样做的好处是，以后再添加新的vehicleType时，您无需修改​​服务-您只需要添加新的VehicleDao实现。