不支持的类型 java.util.concurrent.atomic.AtomicReference

Question

我正在编写 OSGI 服务。启动服务后，我收到以下消息。请建议解决此问题。

@Component (service = Service.class, immediate = true)
public class ServiceImpl implements Service{

@Reference (name = "CounterService", policy = ReferencePolicy.DYNAMIC, cardinality = ReferenceCardinality.MANDATORY,
            bind = "bindCounter", unbind = "unbindCounter", service = CounterService.class)
    public static final AtomicReference<CounterService> myCounterService = new AtomicReference<>();

public void bindCService(CounterService counterService)
{     
    this.cacheService= cacheService;
}

public void unbindService(CounterService cacheService)
{     
    this.cacheService= null;
}

}

我在开始服务后收到此消息

-!MESSAGE [com.xxx.xxx.xxx.CounterImpl(29)] 组件类 com.xxx.xxx.xxx.CounterImpl 中的字段 counterService 具有不受支持的类型 java.util.concurrent.atomic.AtomicReference

Answer 1

那么，为什么是 AtomicReference？您也不需要绑定和取消绑定服务。您似乎很困惑:-) 您可能想看看 videos 或 OSGi starter

对于动态情况，这是可行的：

@Component(immediate = true)
public class ServiceImpl implements Service {

    @Reference    
    volatile CounterService myCounterService;
    
    @Activate
   void activate() {
    ...
    }
    
}

如果

CounterService

不是动态的，这是一个非常好的模式：

@Component(immediate = true)
public class ServiceImpl implements Service {

    final CounterService myCounterService;
    
    @Activate
    public ServiceImpl( @Reference  CounterService  c ) {
        this.myCounterService = c;
    }
    
}

Answer 2

解决此问题的另一种方法是从字段中删除 @Reference 注释并将其添加到绑定方法中。像这样的东西：

@Component (service = Service.class, immediate = true)
public class ServiceImpl implements Service{

    public static final AtomicReference<CounterService> myCounterService = new AtomicReference<>();

@Reference (name = "CounterService", policy = ReferencePolicy.DYNAMIC, cardinality = ReferenceCardinality.MANDATORY,
            bind = "bindCounterService", unbind = "unbindCounterService", service = CounterService.class)
public void bindCounterService(CounterService counterService)
{     
     myCounterService = counterService;
}

public void unbindCounterService(CounterService counterService)
{     
    myCounterService = null;
}

}