Quartz作业执行空指针异常

Question

当quartz触发作业执行时，HoldService.unHold（）方法抛出空指针异常。

   public class SampleJob extends QuartzJobBean {
        @Autowired
        private HoldingService holdingService;
    @Override
        public void executeInternal(JobExecutionContext context) throws JobExecutionException {
            holdingService.unHold();
        }
    }

服务

public interface HoldingService {
    void unHold();
}

@Service("HoldingService")
@Scope("prototype")
public class HoldingServiceImpl implements HoldingService {
    @Override
    public void unHoldCycle() {}

}