程序包 ohos.data.distributed.user

接口 SingleKvStore

所有超级接口:

KvStore

public interface SingleKvStore
extends KvStore

Provides methods related to single-version distributed databases.

To create a SingleKvStore database, you can use the KvManager.getKvStore(Options, String) method with KvStoreType set to SINGLE_VERSION for the input parameter Options. This database synchronizes data to other databases in time sequence. The SingleKvStore database does not support synchronous transactions, or data search using snapshots.

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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 key)	Obtains the boolean value of a specified key.
byte[]	getByteArray(String key)	Obtains the byte[] value of a specified key.
double	getDouble(String key)	Obtains the double value of a specified key.
List<Entry>	getEntries(String keyPrefix)	Obtains all key-value pairs that match a specified key prefix.
List<Entry>	getEntries(Query query)	Obtains the list of key-value pairs matching the specified Query object.
float	getFloat(String key)	Obtains the float value of a specified key.
int	getInt(String key)	Obtains the int value of a specified key.
KvStoreResultSet	getResultSet(String keyPrefix)	Obtains the result sets with a specified prefix from a KvStore database.
KvStoreResultSet	getResultSet(Query query)	Obtains the KvStoreResultSet object matching the specified Query object.
int	getResultSize(Query query)	Obtains the number of results matching the specified Query object.
SecurityLevel	getSecurityLevel()	Get the security level of the database.
String	getString(String key)	Obtains the String value of a specified key.
void	registerSyncCallback(SyncCallback syncCallback)	Register Synchronizes SingleKvStore databases callback.
void	removeDeviceData(String deviceId)
void	setSyncParam(int defaultAllowedDelayMs)	Sets the default delay allowed for database synchronization.
void	sync(List<String> deviceIdList, SyncMode mode)	Synchronizes SingleKvStore databases.
void	sync(List<String> deviceIdList, SyncMode mode, int allowedDelayMs)	Synchronizes the database to the specified devices with the specified delay allowed.
void	unRegisterSyncCallback()	UnRegister Synchronizes SingleKvStore 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 key)
            throws KvStoreException

Obtains the boolean value of a specified key.

参数:

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 key)
    throws KvStoreException

Obtains the int value of a specified key.

参数:

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 key)
        throws KvStoreException

Obtains the float value of a specified key.

参数:

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 key)
          throws KvStoreException

Obtains the double value of a specified key.

参数:

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 key)
          throws KvStoreException

Obtains the String value of a specified key.

参数:

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 key)
             throws KvStoreException

Obtains the byte[] value of a specified key.

参数:

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 keyPrefix)
                throws KvStoreException

Obtains all key-value pairs that match a specified key prefix.

参数:

keyPrefix - Indicates the key prefix to match.

返回:

Returns the list of all key-value pairs that match the specified key prefix.

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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getResultSet

KvStoreResultSet getResultSet(String keyPrefix)
                       throws KvStoreException

Obtains the result sets with a specified prefix from a KvStore database. 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:

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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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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sync

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

Synchronizes SingleKvStore 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 SingleKvStore databases are to be synchronized.

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

抛出:

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

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sync

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

Synchronizes the database to the specified devices with the specified delay allowed.

参数:

deviceIdList - Indicates the list of devices to which to synchronize the database.

mode - Indicates the synchronization mode. The value can be PUSH, PULL, or PUSH_PULL.

allowedDelayMs - Indicates the delay allowed for the synchronization, in milliseconds.

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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removeDeviceData

void removeDeviceData(String deviceId)
               throws KvStoreException

抛出:

KvStoreException

registerSyncCallback

void registerSyncCallback(SyncCallback syncCallback)
                   throws KvStoreException

Register Synchronizes SingleKvStore 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 SingleKvStore database is available.

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unRegisterSyncCallback

void unRegisterSyncCallback()
                     throws KvStoreException

UnRegister Synchronizes SingleKvStore databases callback.

抛出:

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

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setSyncParam

void setSyncParam(int defaultAllowedDelayMs)
           throws KvStoreException

Sets the default delay allowed for database synchronization.

参数:

defaultAllowedDelayMs - Indicates the default delay allowed for the database synchronization, in milliseconds.

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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getSecurityLevel

SecurityLevel getSecurityLevel()
                        throws KvStoreException

Get the security level of the database.

返回:

SecurityLevel SecurityLevel the security level of the database.

抛出:

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

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