Interface ShardingKeyProvider

public interface ShardingKeyProvider

Strategy interface for determining sharding keys which are used to establish direct shard connections in the context of sharded databases. This is used as a callback for providing the current sharding key (plus optionally a super sharding key) in ShardingKeyDataSourceAdapter.

Can be used as a functional interface (for example, with a lambda expression) for a simple sharding key, or as a two-method interface when including a super sharding key as well.

Since:

6.1.2

Author:

Mohamed Lahyane (Anir), Juergen Hoeller

See Also:

• ShardingKeyDataSourceAdapter.setShardingKeyProvider(org.springframework.jdbc.datasource.ShardingKeyProvider)

Method Summary

Modifier and Type	Method	Description
@Nullable ShardingKey	getShardingKey()	Determine the sharding key.
default @Nullable ShardingKey	getSuperShardingKey()	Determine the super sharding key, if any.

Method Details

getShardingKey

@Nullable ShardingKey getShardingKey()
                              throws SQLException

Determine the sharding key. This method returns the sharding key relevant to the current context which will be used to obtain a direct shard connection.

Returns:

the sharding key, or null if it is not available or cannot be determined

Throws:

SQLException - if an error occurs while obtaining the sharding key

getSuperShardingKey

default @Nullable ShardingKey getSuperShardingKey()
                                           throws SQLException

Determine the super sharding key, if any. This method returns the super sharding key relevant to the current context which will be used to obtain a direct shard connection.

Returns:

the super sharding key, or null if it is not available or cannot be determined (the default)

Throws:

SQLException - if an error occurs while obtaining the super sharding key