这是依赖库的版本信息
<curator.recipes.version>4.2.0</curator.recipes.version>
<zookeeper.version>3.4.10</zookeeper.version>
[dubbo-.3.1.6.txt](https://github.com/apache/dubbo/files/11177448/dubbo-.3.1.6.txt)
有没有大佬帮忙看下什么问题导致，万分感谢！！！
import org.apache.dubbo.metadata.MetadataInfo;
import org.apache.dubbo.metadata.report.MetadataReport;
import org.apache.dubbo.metadata.report.MetadataReportInstance;
import org.apache.dubbo.metadata.report.identifier.SubscriberMetadataIdentifier;
import org.apache.dubbo.registry.NotifyListener;
import org.apache.dubbo.registry.client.event.listener.ServiceInstancesChangedListener;
import org.apache.dubbo.registry.client.metadata.MetadataUtils;
import org.apache.dubbo.registry.client.metadata.ServiceInstanceMetadataUtils;
import org.apache.dubbo.registry.client.metadata.store.MetaCacheManager;
import org.apache.dubbo.rpc.model.ApplicationModel;
import static org.apache.dubbo.common.constants.CommonConstants.DEFAULT_METADATA_INFO_CACHE_EXPIRE;
import static org.apache.dubbo.common.constants.CommonConstants.DEFAULT_METADATA_INFO_CACHE_SIZE;
import static org.apache.dubbo.common.constants.CommonConstants.DEFAULT_METADATA_STORAGE_TYPE;
import static org.apache.dubbo.common.constants.CommonConstants.METADATA_INFO_CACHE_EXPIRE_KEY;
import static org.apache.dubbo.common.constants.CommonConstants.METADATA_INFO_CACHE_SIZE_KEY;
import static org.apache.dubbo.common.constants.CommonConstants.REGISTRY_LOCAL_FILE_CACHE_ENABLED;
import static org.apache.dubbo.common.constants.CommonConstants.REMOTE_METADATA_STORAGE_TYPE;
import static org.apache.dubbo.common.constants.LoggerCodeConstants.INTERNAL_ERROR;
import static org.apache.dubbo.common.constants.LoggerCodeConstants.REGISTRY_FAILED_FETCH_INSTANCE;
import static org.apache.dubbo.common.constants.LoggerCodeConstants.REGISTRY_FAILED_LOAD_METADATA;
import static org.apache.dubbo.common.constants.RegistryConstants.REGISTRY_CLUSTER_KEY;
import static org.apache.dubbo.metadata.RevisionResolver.EMPTY_REVISION;
import static org.apache.dubbo.registry.client.metadata.ServiceInstanceMetadataUtils.EXPORTED_SERVICES_REVISION_PROPERTY_NAME;
import static org.apache.dubbo.registry.client.metadata.ServiceInstanceMetadataUtils.getExportedServicesRevision;
import static org.apache.dubbo.registry.client.metadata.ServiceInstanceMetadataUtils.isValidInstance;
import static org.apache.dubbo.registry.client.metadata.ServiceInstanceMetadataUtils.setMetadataStorageType;
/**
 * Each service discovery is bond to one application.
 */
public abstract class AbstractServiceDiscovery implements ServiceDiscovery {