Class ShardingKeyDataSourceAdapter

java.lang.Object

org.springframework.jdbc.datasource.DelegatingDataSource

org.springframework.jdbc.datasource.ShardingKeyDataSourceAdapter

All Implemented Interfaces:

Wrapper, CommonDataSource, DataSource, InitializingBean

public class ShardingKeyDataSourceAdapter
extends DelegatingDataSource

An adapter for a target DataSource, designed to apply sharding keys, if specified, to every standard #getConnection call, returning a direct connection to the shard corresponding to the specified sharding key value. All other methods simply delegate to the corresponding methods of the target DataSource.

The target DataSource must implement the createConnectionBuilder() method; otherwise, a SQLFeatureNotSupportedException will be thrown when attempting to acquire shard connections.

This adapter needs to be configured with a ShardingKeyProvider callback which is used to get the current sharding keys for every #getConnection call, for example:

ShardingKeyDataSourceAdapter dataSourceAdapter = new ShardingKeyDataSourceAdapter(dataSource);
dataSourceAdapter.setShardingKeyProvider(() -> dataSource.createShardingKeyBuilder()
    .subkey(SecurityContextHolder.getContext().getAuthentication().getName(), JDBCType.VARCHAR).build());

Since:

6.1.2

Author:

Mohamed Lahyane (Anir), Juergen Hoeller

See Also:

• getConnection()
• createConnectionBuilder()
• UserCredentialsDataSourceAdapter

Constructor Summary

Constructors

Constructor	Description
ShardingKeyDataSourceAdapter(DataSource dataSource)	Create a new instance of ShardingKeyDataSourceAdapter, wrapping the given DataSource.
ShardingKeyDataSourceAdapter(DataSource dataSource, ShardingKeyProvider shardingKeyProvider)	Create a new instance of ShardingKeyDataSourceAdapter, wrapping the given DataSource.

Method Summary

Modifier and Type	Method	Description
ConnectionBuilder	createConnectionBuilder()	Create a new instance of ConnectionBuilder using the target DataSource's createConnectionBuilder() method and set the appropriate sharding keys from the configured ShardingKeyProvider.
Connection	getConnection()	Obtain a connection to the database shard using the provided sharding key and super sharding key (if available).
Connection	getConnection(String username, String password)	Obtain a connection to the database shard using the provided username and password, considering the sharding keys (if available) and the given credentials.
void	setShardingKeyProvider(ShardingKeyProvider shardingKeyProvider)	Set the ShardingKeyProvider for this adapter.

Methods inherited from class DelegatingDataSource

afterPropertiesSet, createShardingKeyBuilder, getLoginTimeout, getLogWriter, getParentLogger, getTargetDataSource, isWrapperFor, obtainTargetDataSource, setLoginTimeout, setLogWriter, setTargetDataSource, unwrap

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ShardingKeyDataSourceAdapter

public ShardingKeyDataSourceAdapter(DataSource dataSource)

Create a new instance of ShardingKeyDataSourceAdapter, wrapping the given DataSource.

Parameters:

dataSource - the target DataSource to be wrapped

ShardingKeyDataSourceAdapter

public ShardingKeyDataSourceAdapter(DataSource dataSource,
 ShardingKeyProvider shardingKeyProvider)

Create a new instance of ShardingKeyDataSourceAdapter, wrapping the given DataSource.

Parameters:

dataSource - the target DataSource to be wrapped

shardingKeyProvider - the ShardingKeyProvider used to get the sharding keys

Method Details

setShardingKeyProvider

public void setShardingKeyProvider(ShardingKeyProvider shardingKeyProvider)

Set the ShardingKeyProvider for this adapter.

getConnection

public Connection getConnection()
                         throws SQLException

Obtain a connection to the database shard using the provided sharding key and super sharding key (if available).

The sharding key is obtained from the configured ShardingKeyProvider.

Specified by:

getConnection in interface DataSource

Overrides:

getConnection in class DelegatingDataSource

Returns:

a Connection object representing a direct shard connection

Throws:

SQLException - if an error occurs while creating the connection

See Also:

• createConnectionBuilder()

getConnection

public Connection getConnection(String username,
 String password)
                         throws SQLException

Obtain a connection to the database shard using the provided username and password, considering the sharding keys (if available) and the given credentials.

The sharding key is obtained from the configured ShardingKeyProvider.

Specified by:

getConnection in interface DataSource

Overrides:

getConnection in class DelegatingDataSource

Parameters:

username - the database user on whose behalf the connection is being made

password - the user's password

Returns:

a Connection object representing a direct shard connection

Throws:

SQLException - if an error occurs while creating the connection

createConnectionBuilder

public ConnectionBuilder createConnectionBuilder()
                                          throws SQLException

Create a new instance of ConnectionBuilder using the target DataSource's createConnectionBuilder() method and set the appropriate sharding keys from the configured ShardingKeyProvider.

Specified by:

createConnectionBuilder in interface DataSource

Overrides:

createConnectionBuilder in class DelegatingDataSource

Returns:

a ConnectionBuilder object representing a builder for direct shard connections

Throws:

SQLException - if an error occurs while creating the ConnectionBuilder