#fixed code
                                private void parseRpcExporterAnnotation(RpcExporter rpcExporter,
                                            ConfigurableListableBeanFactory beanFactory,
                                            Object bean) {
        Class<?> serviceClass = AopUtils.getTargetClass(bean);
        Class<?>[] interfaces = ClassUtils.getAllInterfacesForClass(serviceClass);
        if (interfaces.length != 1) {
            throw new RuntimeException("service interface num must equal 1, " + serviceClass.getName());
        }
        Class<?> serviceInterface = interfaces[0];
        BrpcConfig brpcConfig = getServiceConfig(beanFactory, serviceInterface);

        // if there are multi service on one port, the first service configs effect only.
        Integer port = brpcConfig.getServer().getPort();
        RpcServiceExporter rpcServiceExporter = portMappingExporters.get(port);
        if (rpcServiceExporter == null) {
            rpcServiceExporter = new RpcServiceExporter();
            portMappingExporters.put(port, rpcServiceExporter);
            rpcServiceExporter.setServicePort(port);
            rpcServiceExporter.copyFrom(brpcConfig.getServer());
            if (brpcConfig.getNaming() != null) {
                rpcServiceExporter.setNamingServiceUrl(brpcConfig.getNaming().getNamingServiceUrl());
            }
        }

        // interceptor
        if (brpcConfig.getServer() != null
                && StringUtils.isNoneBlank(brpcConfig.getServer().getInterceptorBeanName())) {
            Interceptor interceptor = beanFactory.getBean(
                    brpcConfig.getServer().getInterceptorBeanName(), Interceptor.class);
            if (rpcServiceExporter.getInterceptors() != null &&
                    !rpcServiceExporter.getInterceptors().contains(interceptor)) {
                rpcServiceExporter.getInterceptors().add(interceptor);
            } else {
                List<Interceptor> interceptors = new ArrayList<>();
                interceptors.add(interceptor);
                rpcServiceExporter.setInterceptors(interceptors); // must be immutable
            }
        }

        // naming options
        rpcServiceExporter.getServiceNamingOptions().put(bean, brpcConfig.getNaming());

        if (brpcConfig.getServer() != null && brpcConfig.getServer().isUseSharedThreadPool()) {
            rpcServiceExporter.getCustomOptionsServiceMap().put(brpcConfig.getServer(), bean);
        } else {
            rpcServiceExporter.getRegisterServices().add(bean);
        }

        if (protobufRpcAnnotationResolverListener != null) {
            protobufRpcAnnotationResolverListener.onRpcExporterAnnotationParsered(
                    rpcExporter, port, bean, rpcServiceExporter.getRegisterServices());
        }
    }
#vulnerable code 
                                private void parseRpcExporterAnnotation(RpcExporter rpcExporter,
                                            ConfigurableListableBeanFactory beanFactory,
                                            Object bean) {
        Class<?> serviceClass = AopUtils.getTargetClass(bean);
        Class<?>[] interfaces = ClassUtils.getAllInterfacesForClass(serviceClass);
        if (interfaces.length != 1) {
            throw new RuntimeException("service interface num must equal 1, " + serviceClass.getName());
        }
        Class<?> serviceInterface = interfaces[0];
        BrpcConfig brpcConfig = getServiceConfig(beanFactory, serviceInterface);

        // if there are multi service on one port, the first service configs effect only.
        Integer port = brpcConfig.getServer().getPort();
        RpcServiceExporter rpcServiceExporter = portMappingExporters.get(port);
        if (rpcServiceExporter == null) {
            rpcServiceExporter = new RpcServiceExporter();
            portMappingExporters.put(port, rpcServiceExporter);
            rpcServiceExporter.setServicePort(port);
            rpcServiceExporter.copyFrom(brpcConfig.getServer());
            if (brpcConfig.getNaming() != null) {
                rpcServiceExporter.setNamingServiceUrl(brpcConfig.getNaming().getNamingServiceUrl());
            }
        }

        // interceptor
        if (brpcConfig.getServer() != null
                && StringUtils.isNoneBlank(brpcConfig.getServer().getInterceptorBeanName())) {
            Interceptor interceptor = beanFactory.getBean(
                    brpcConfig.getServer().getInterceptorBeanName(), Interceptor.class);
            if (rpcServiceExporter.getInterceptors() != null) {
                rpcServiceExporter.getInterceptors().add(interceptor);
            } else {
                rpcServiceExporter.setInterceptors(Arrays.asList(interceptor));
            }
        }

        // naming options
        rpcServiceExporter.getServiceNamingOptions().put(bean, brpcConfig.getNaming());

        if (brpcConfig.getServer() != null && brpcConfig.getServer().isUseSharedThreadPool()) {
            rpcServiceExporter.getCustomOptionsServiceMap().put(brpcConfig.getServer(), bean);
        } else {
            rpcServiceExporter.getRegisterServices().add(bean);
        }

        if (protobufRpcAnnotationResolverListener != null) {
            protobufRpcAnnotationResolverListener.onRpcExporterAnnotationParsered(
                    rpcExporter, port, bean, rpcServiceExporter.getRegisterServices());
        }
    } 
                            #location 13 
                            #vulnerability type NULL_DEREFERENCE