如何根据用户地区代码注入服务类

我想从用户地址中的区号获取公交/公交车站信息打开api。如何根据用户地区代码注入服务类

区域是城市，城市提供彼此不同的巴士信息api。

TrafficController.java

@Controller 
public class TrafficController { 

    .... 
    @Autowired 
    public UserService userService; 

    public TrafficService trafficService; 
    .... 

    @RequestMapping(value="/api/traffic/stations") 
    public List<....> getNearStations(HttpServerletRequest req) { 
     String userId = SessionAttrs.getUserId(req.getSession()); 
     User user = userSerivce.getUser(userId); 

     trafficService = (TrafficService) Class.forName("com.myservice.service.impl.TrafficService_"+user.house.apt.address.area_code + "_Impl").newInstence(); 
     return trafficService.getStations(user.house.apt.latitude, user.house.apt.longitude, 300, 2); 

    } 
}

TrafficService_11_Impl.java

@Service 
public Class TrafficService_11_Impl implemnet TrafficService { 
    @Autowired 
    TrafficRepository trafficRepository; 

    @Override 
    public List<Station> getStations(double lat, double lng, int ratius, int retryCount) { 

     final String cacheKey = "getStations " + lat + " " + lng + " " + radius; 
     TrafficeCache cache = trafficRepository.fineOne(chcheKey); // run time NullPointerException, trafficRepository is null 

     if (null == cache) { 
      ... 
      get area code 11 api call logic 
      ... 
     } 

     ... 
     return ...; 
    } 
}

TrafficRepository.java

public interface TrafficRepository extends JpaRepository<TrafficCache, String> { 
}

该代码发生运行时的NullPointerException在

TrafficService_11_Impl.java在

TrafficeCache缓存= trafficRepository.fineOne（chcheKey）;

运行时NullPointerException异常，trafficRepository为null

Otherly在TrafficController.java

@Autowired 
public TrafficService trafficService

拖放代码

trafficService = (TrafficService) Class.forName("com.myservice.service.impl.TrafficService_"+user.house.apt.address.area_code + "_Impl").newInstence();

是正确的结果

如何在String引导中根据用户区号注入服务类？

来源

2015-11-20 basscraft

缩进代码，添加更好的格式。问题仍然很少问 –

您是否打算为*每个可能的区号创建一个单独的'TrafficService'实现？无论你的“区号”是什么，以及可能有多少，这都不是你应该怎么做的。创建一个封装区域代码之间差异的'TrafficService'实现。 – kryger

[为什么我的Spring @Autowired字段为空]？（http://stackoverflow.com/questions/19896870/why-is-my-spring-autowired-field-null） – chrylis

TrafficController.java

@Controller 
public class TrafficController { 

    .... 
    @Autowired 
    private ApplicationContext context; 

    @Autowired 
    public UserService userService; 

    public TrafficService trafficService; 
    .... 

    @RequestMapping(value="/api/traffic/stations") 
    public List<....> getNearStations(HttpServerletRequest req) { 
     String userId = SessionAttrs.getUserId(req.getSession()); 
     User user = userSerivce.getUser(userId); 

     trafficService = (TrafficService) context.getBean(Class.forName("com.myservice.service.impl.TrafficService_"+user.house.apt.address.area_code + "_Impl")); 
     return trafficService.getStations(user.house.apt.latitude, user.house.apt.longitude, 300, 2); 

    } 
}

这是正确的结果

来源

2015-11-23 02:11:00 basscraft

如何根据用户地区代码注入服务类

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