程序包 ohos.data.distributed.common

接口 KvManager

public interface KvManager

Provides interfaces to manage a KvStore database, including obtaining, closing, and deleting the KvStore.

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SystemCapability

SystemCapability.Data#DATA_DISTRIBUTEDDATAMGR

方法概要

限定符和类型	方法	说明
void	closeKvStore(KvStore kvStore)	Closes the KvStore database.
void	deleteKvStore(String storeId)	Deletes the KvStore database identified by storeId.
List<String>	getAllKvStoreId()	Obtains the storeId of all KvStore databases that are created by using the getKvStore method and not deleted by calling the deleteKvStore method.
List<DeviceInfo>	getConnectedDevicesInfo(DeviceFilterStrategy strategy)	Get all connected devices information, which has distributed capability.
<KVSTORE extends KvStore> KVSTORE	getKvStore(Options options, String storeId)	Creates and obtains a KvStore database by specifying Options and storeId.
DeviceInfo	getLocalDeviceInfo()	Get local device information;
void	registerDeviceChangeCallback(DeviceChangeCallback callback, DeviceFilterStrategy strategy)	register DeviceChangeCallback to get notification when device's status changed
void	unRegisterDeviceChangeCallback(DeviceChangeCallback callback)	unRegister DeviceChangeCallback and can not receive notification

方法详细资料

getKvStore

<KVSTORE extends KvStore> KVSTORE getKvStore(Options options,
                                             String storeId)
                                      throws KvStoreException

Creates and obtains a KvStore database by specifying Options and storeId.

参数:

options - Indicates the options used for creating and obtaining the KvStore database, including isCreateIfMissing, isEncrypt, and KvStoreType.

storeId - Identifies the KvStore database. The value of this parameter must be unique for the same application, and different applications can share the same value.

返回:

Returns a SingleKvStore, or DeviceKvStore, as specified by KvStoreType.

抛出:

KvStoreException - Throws this exception if any of the following errors occurs: IINVALID_ARGUMENT, SERVER_UNAVAILABLE, PERMISSION_DENIED, and IPC_ERROR, DB_ERROR.

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closeKvStore

void closeKvStore(KvStore kvStore)
           throws KvStoreException

Closes the KvStore database.

Warning: This method is not thread-safe. If you call this method to stop a KvStore database that is running, your thread may crash.

The KvStore database to close must be an object created by using the getKvStore method. Before using this method, release the resources created for the database, for example, KvStoreResultSet for SingleKvStore, otherwise closing the database will fail. If you are attempting to close a database that is already closed, an error will be returned.

参数:

kvStore - Indicates the KvStore database to close.

抛出:

KvStoreException - Throws this exception if any of the following errors occurs: INVALID_ARGUMENT, ERVER_UNAVAILABLE, STORE_NOT_OPEN, STORE_NOT_FOUND, DB_ERROR, PERMISSION_DENIED, and IPC_ERROR.

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deleteKvStore

void deleteKvStore(String storeId)
            throws KvStoreException

Deletes the KvStore database identified by storeId.

Before using this method, close all KvStore instances in use that are identified by the same storeId.

You can use this method to delete a KvStore database not in use. After the database is deleted, all its data will be lost.

参数:

storeId - Identifies the KvStore database to delete.

抛出:

KvStoreException - Throws this exception if any of the following errors occurs: INVALID_ARGUMENT, SERVER_UNAVAILABLE, STORE_NOT_FOUND, DB_ERROR, PERMISSION_DENIED, and IPC_ERROR.

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getAllKvStoreId

List<String> getAllKvStoreId()
                      throws KvStoreException

Obtains the storeId of all KvStore databases that are created by using the getKvStore method and not deleted by calling the deleteKvStore method.

返回:

Returns the storeId of all created KvStore databases.

抛出:

KvStoreException - Throws this exception if any of the following errors occurs: SERVER_UNAVAILABLE, DB_ERROR, PERMISSION_DENIED, and IPC_ERROR.

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getConnectedDevicesInfo

List<DeviceInfo> getConnectedDevicesInfo(DeviceFilterStrategy strategy)
                                  throws KvStoreException

Get all connected devices information, which has distributed capability.

参数:

strategy - device filter strategy DeviceFilterStrategy

返回:

device information list;

抛出:

KvStoreException - exception maybe occurs.

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getLocalDeviceInfo

DeviceInfo getLocalDeviceInfo()
                       throws KvStoreException

Get local device information;

返回:

local device information;

抛出:

KvStoreException - exception maybe occurs.

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registerDeviceChangeCallback

void registerDeviceChangeCallback(DeviceChangeCallback callback,
                                  DeviceFilterStrategy strategy)
                           throws KvStoreException

register DeviceChangeCallback to get notification when device's status changed

参数:

callback - device change callback DeviceChangeCallback

strategy - device filter strategy DeviceFilterStrategy

抛出:

KvStoreException - exception maybe occurs.

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unRegisterDeviceChangeCallback

void unRegisterDeviceChangeCallback(DeviceChangeCallback callback)
                             throws KvStoreException

unRegister DeviceChangeCallback and can not receive notification

参数:

callback - device change callback DeviceChangeCallback which has been registered.

抛出:

KvStoreException - exception maybe occurs.

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