程序包 ohos.data.distributed.device

接口 DeviceKvStore

所有超级接口:

KvStore

public interface DeviceKvStore
extends KvStore

Manages distributed data by device in a distributed system.

To create a DeviceKvStore database, you can use the KvManager.getKvStore(Options, String) method with KvStoreType set to DEVICE_COLLABORATION for the input parameter Options. This database manages distributed data by device, and cannot modify data synchronized from remote devices. When an application writes a key-value pair entry into the database, the system automatically adds the ID of the device running the application to the key.

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SystemCapability

SystemCapability.Data#DATA_DISTRIBUTEDDATAMGR

字段概要

从接口继承的字段 ohos.data.distributed.common.KvStore

MAX_BATCH_SIZE, MAX_KEY_LENGTH, MAX_KEY_LENGTH_DEVICE, MAX_QUERY_LENGTH, MAX_STORE_ID_LENGTH, MAX_VALUE_LENGTH

方法概要

限定符和类型	方法	说明
void	closeResultSet(KvStoreResultSet resultSet)	Closes a KvStoreResultSet object returned by getResultSet.
boolean	getBoolean(String deviceId, String key)	Obtains the boolean value matching a specified device ID and key.
byte[]	getByteArray(String deviceId, String key)	Obtains the byte[] value matching a specified device ID and key.
double	getDouble(String deviceId, String key)	Obtains the double value matching a specified device ID and key.
List<Entry>	getEntries(String deviceId, String keyPrefix)	Obtains all key-value pairs matching a specified device ID and key prefix.
List<Entry>	getEntries(String deviceId, Query query)	Obtains the list of key-value pairs matching a specified device ID and Query object.
List<Entry>	getEntries(Query query)	Obtains the list of key-value pairs matching the specified Query object.
float	getFloat(String deviceId, String key)	Obtains the float value matching a specified device ID and key.
int	getInt(String deviceId, String key)	Obtains the int value matching a specified device ID and key.
KvStoreResultSet	getResultSet(String deviceId, String keyPrefix)	Obtains the KvStoreResultSet object matching the specified device ID and key prefix.
KvStoreResultSet	getResultSet(String deviceId, Query query)	Obtains the KvStoreResultSet object matching a specified device ID and Query object.
KvStoreResultSet	getResultSet(Query query)	Obtains the KvStoreResultSet object matching the specified Query object.
int	getResultSize(String deviceId, Query query)	Obtains the number of results matching a specified device ID and Query object.
int	getResultSize(Query query)	Obtains the number of results matching the specified Query object.
String	getString(String deviceId, String key)	Obtains the String value matching a specified device ID and key.
void	registerSyncCallback(SyncCallback syncCallback)	Register Synchronizes DeviceKvStore databases callback.
void	removeDeviceData(String deviceId)	Removes data of a specified device from the current database.
void	sync(List<String> deviceIdList, SyncMode mode)	Synchronizes DeviceKvStore databases.
void	unRegisterSyncCallback()	UnRegister Synchronizes DeviceKvStore databases callback.

从接口继承的方法 ohos.data.distributed.common.KvStore

commit, delete, deleteBatch, enableSync, getStoreId, putBatch, putBoolean, putByteArray, putDouble, putFloat, putInt, putString, rollback, setSyncRange, startTransaction, subscribe, unSubscribe

方法详细资料

getBoolean

boolean getBoolean(String deviceId,
                   String key)
            throws KvStoreException

Obtains the boolean value matching a specified device ID and key.

参数:

deviceId - Identifies the device whose data is to be queried.

key - Indicates the key of the boolean value to be queried.

返回:

Returns the boolean value matching the given criteria.

抛出:

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

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getInt

int getInt(String deviceId,
           String key)
    throws KvStoreException

Obtains the int value matching a specified device ID and key.

参数:

deviceId - Identifies the device whose data is to be queried.

key - Indicates the key of the int value to be queried.

返回:

Returns the int value matching the given criteria.

抛出:

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

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getFloat

float getFloat(String deviceId,
               String key)
        throws KvStoreException

Obtains the float value matching a specified device ID and key.

参数:

deviceId - Identifies the device whose data is to be queried.

key - Indicates the key of the float value to be queried.

返回:

Returns the float value matching the given criteria.

抛出:

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

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getDouble

double getDouble(String deviceId,
                 String key)
          throws KvStoreException

Obtains the double value matching a specified device ID and key.

参数:

deviceId - Identifies the device whose data is to be queried.

key - Indicates the key of the double value to be queried.

返回:

Returns the double value matching the given criteria.

抛出:

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

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getString

String getString(String deviceId,
                 String key)
          throws KvStoreException

Obtains the String value matching a specified device ID and key.

参数:

deviceId - Identifies the device whose data is to be queried.

key - Indicates the key of the String value to be queried.

返回:

Returns the String value matching the given criteria.

抛出:

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

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getByteArray

byte[] getByteArray(String deviceId,
                    String key)
             throws KvStoreException

Obtains the byte[] value matching a specified device ID and key.

参数:

deviceId - Identifies the device whose data is to be queried.

key - Indicates the key of the byte[] value to be queried.

返回:

Returns the byte[] value matching the given criteria.

抛出:

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

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getEntries

List<Entry> getEntries(String deviceId,
                       String keyPrefix)
                throws KvStoreException

Obtains all key-value pairs matching a specified device ID and key prefix.

参数:

deviceId - Identifies the device whose data is to be queried.

keyPrefix - Indicates the key prefix to match.

返回:

Returns the list of all key-value pairs meeting the given criteria.

抛出:

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

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getEntries

List<Entry> getEntries(Query query)
                throws KvStoreException

Obtains the list of key-value pairs matching the specified Query object.

参数:

query - Indicates the Query object.

返回:

Returns the list of key-value pairs matching the specified Query object.

抛出:

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

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getEntries

List<Entry> getEntries(String deviceId,
                       Query query)
                throws KvStoreException

Obtains the list of key-value pairs matching a specified device ID and Query object.

参数:

deviceId - Indicates the ID of the device to which the key-value pairs belong.

query - Indicates the Query object.

返回:

Returns the list of key-value pairs matching the specified Query object.

抛出:

INVALID_ARGUMENT - Throws this exception if either or both of the input parameters are incorrect.

SERVER_UNAVAILABLE - Throws this exception if the service is unavailable.

IPC_ERROR - Throws this exception if an IPC error occurs.

DB_ERROR - Throws this exception if a database error occurs.

KvStoreException

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getResultSet

KvStoreResultSet getResultSet(String deviceId,
                              String keyPrefix)
                       throws KvStoreException

Obtains the KvStoreResultSet object matching the specified device ID and key prefix.

The KvStoreResultSet object can be used to query all key-value pairs that meet the search criteria. Each KvStore instance can have a maximum of four KvStoreResultSet objects at the same time. If you have created four objects, calling this method will return a failure. Therefore, you are advised to call the closeResultSet method to close unnecessary KvStoreResultSet objects in a timely manner.

参数:

deviceId - Identifies the device whose data is to be queried.

keyPrefix - Indicates the key prefix to match.

返回:

Returns the KvStoreResultSet objects.

抛出:

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

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getResultSet

KvStoreResultSet getResultSet(Query query)
                       throws KvStoreException

Obtains the KvStoreResultSet object matching the specified Query object.

参数:

query - Indicates the Query object.

返回:

Returns the KvStoreResultSet object matching the specified Query object.

抛出:

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

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getResultSet

KvStoreResultSet getResultSet(String deviceId,
                              Query query)
                       throws KvStoreException

Obtains the KvStoreResultSet object matching a specified device ID and Query object.

参数:

deviceId - Indicates the ID of the device to which the KvStoreResultSet object belongs.

query - Indicates the Query object.

返回:

Returns the KvStoreResultSet object matching the specified Query object.

抛出:

INVALID_ARGUMENT - Throws this exception if either or both of the input parameters are incorrect.

SERVER_UNAVAILABLE - Throws this exception if the service is unavailable.

IPC_ERROR - Throws this exception if an IPC error occurs.

DB_ERROR - Throws this exception if a database error occurs.

KvStoreException

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closeResultSet

void closeResultSet(KvStoreResultSet resultSet)
             throws KvStoreException

Closes a KvStoreResultSet object returned by getResultSet.

参数:

resultSet - Indicates the KvStoreResultSet object to close.

抛出:

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

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getResultSize

int getResultSize(Query query)
           throws KvStoreException

Obtains the number of results matching the specified Query object.

参数:

query - Indicates the Query object.

返回:

Returns the number of results matching the specified Query object.

抛出:

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

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getResultSize

int getResultSize(String deviceId,
                  Query query)
           throws KvStoreException

Obtains the number of results matching a specified device ID and Query object.

参数:

deviceId - Indicates the ID of the device to which the results belong.

query - Indicates the Query object.

返回:

Returns the number of results matching the specified Query object.

抛出:

INVALID_ARGUMENT - Throws this exception if either or both of the input parameters are incorrect.

SERVER_UNAVAILABLE - Throws this exception if the service is unavailable.

IPC_ERROR - Throws this exception if an IPC error occurs.

DB_ERROR - Throws this exception if a database error occurs.

KvStoreException

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sync

void sync(List<String> deviceIdList,
          SyncMode mode)
   throws KvStoreException

Synchronizes DeviceKvStore databases.

This method returns immediately and sync result will be returned through asynchronous callback.

参数:

deviceIdList - Indicates the list of IDs of devices whose DeviceKvStore databases are to be synchronized.

mode - Indicates the synchronization mode, PUSH, PULL, or PUSH_PULL.

抛出:

KvStoreException - Throws this exception if no DeviceKvStore database is available.

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removeDeviceData

void removeDeviceData(String deviceId)
               throws KvStoreException

Removes data of a specified device from the current database. This method is used to remove only the data synchronized from remote devices. This operation does not synchronize data to other databases or affect subsequent data synchronization.

参数:

deviceId - Identifies the device whose data is to be removed. The value cannot be the current device ID.

抛出:

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

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registerSyncCallback

void registerSyncCallback(SyncCallback syncCallback)
                   throws KvStoreException

Register Synchronizes DeviceKvStore databases callback.

Sync result is returned through asynchronous callback.

参数:

syncCallback - Indicates the callback used to send the synchronization result to the caller.

抛出:

KvStoreException - Throws this exception if no DeviceKvStore database is available.

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unRegisterSyncCallback

void unRegisterSyncCallback()
                     throws KvStoreException

UnRegister Synchronizes DeviceKvStore databases callback.

抛出:

KvStoreException - Throws this exception if no DeviceKvStore database is available.

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