Package org.springframework.jdbc.datasource

Class IsolationLevelDataSourceAdapter

java.lang.Object

org.springframework.jdbc.datasource.DelegatingDataSource

org.springframework.jdbc.datasource.UserCredentialsDataSourceAdapter

org.springframework.jdbc.datasource.IsolationLevelDataSourceAdapter

All Implemented Interfaces:

Wrapper, CommonDataSource, DataSource, InitializingBean

public class IsolationLevelDataSourceAdapter
extends UserCredentialsDataSourceAdapter

An adapter for a target DataSource, applying the current Spring transaction's isolation level (and potentially specified user credentials) to every getConnection call. Also applies the read-only flag, if specified.

Can be used to proxy a target JNDI DataSource that does not have the desired isolation level (and user credentials) configured. Client code can work with this DataSource as usual, not worrying about such settings.

Inherits the capability to apply specific user credentials from its superclass UserCredentialsDataSourceAdapter; see the latter's javadoc for details on that functionality (e.g. UserCredentialsDataSourceAdapter.setCredentialsForCurrentThread(java.lang.String, java.lang.String)).

WARNING: This adapter simply calls Connection.setTransactionIsolation(int) and/or Connection.setReadOnly(boolean) for every Connection obtained from it. It does, however, not reset those settings; it rather expects the target DataSource to perform such resetting as part of its connection pool handling. Make sure that the target DataSource properly cleans up such transaction state.

Since:

2.0.3

Author:

Juergen Hoeller, Sam Brannen

See Also:

• setIsolationLevel(int)
• setIsolationLevelName(java.lang.String)
• UserCredentialsDataSourceAdapter.setUsername(java.lang.String)
• UserCredentialsDataSourceAdapter.setPassword(java.lang.String)

Constructor Summary

Constructors

Constructor	Description
IsolationLevelDataSourceAdapter()

Method Summary

Modifier and Type	Method	Description
protected Connection	doGetConnection(String username, String password)	Applies the current isolation level value and read-only flag to the returned Connection.
protected Integer	getCurrentIsolationLevel()	Determine the current isolation level: either the transaction's isolation level or a statically defined isolation level.
protected Boolean	getCurrentReadOnlyFlag()	Determine the current read-only flag: by default, the transaction's read-only hint.
protected Integer	getIsolationLevel()	Return the statically specified isolation level, or null if none.
void	setIsolationLevel(int isolationLevel)	Specify the default isolation level to use for Connection retrieval, according to the JDBC Connection constants (equivalent to the corresponding Spring TransactionDefinition constants).
final void	setIsolationLevelName(String constantName)	Set the default isolation level by the name of the corresponding constant in TransactionDefinition — for example, "ISOLATION_SERIALIZABLE".

Methods inherited from class org.springframework.jdbc.datasource.UserCredentialsDataSourceAdapter

getConnection, getConnection, removeCredentialsFromCurrentThread, setCatalog, setCredentialsForCurrentThread, setPassword, setSchema, setUsername

Methods inherited from class org.springframework.jdbc.datasource.DelegatingDataSource

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.sql.CommonDataSource

createShardingKeyBuilder

Methods inherited from interface javax.sql.DataSource

createConnectionBuilder

Constructor Details

IsolationLevelDataSourceAdapter

public IsolationLevelDataSourceAdapter()

Method Details

setIsolationLevelName

public final void setIsolationLevelName(String constantName)
                                 throws IllegalArgumentException

Set the default isolation level by the name of the corresponding constant in TransactionDefinition — for example, "ISOLATION_SERIALIZABLE".

If not specified, the target DataSource's default will be used. Note that a transaction-specific isolation value will always override any isolation setting specified at the DataSource level.

Parameters:

constantName - name of the constant

Throws:

IllegalArgumentException

See Also:

• TransactionDefinition.ISOLATION_READ_UNCOMMITTED
• TransactionDefinition.ISOLATION_READ_COMMITTED
• TransactionDefinition.ISOLATION_REPEATABLE_READ
• TransactionDefinition.ISOLATION_SERIALIZABLE
• setIsolationLevel(int)

setIsolationLevel

public void setIsolationLevel(int isolationLevel)

Specify the default isolation level to use for Connection retrieval, according to the JDBC Connection constants (equivalent to the corresponding Spring TransactionDefinition constants).

If not specified, the target DataSource's default will be used. Note that a transaction-specific isolation value will always override any isolation setting specified at the DataSource level.

See Also:

• Connection.TRANSACTION_READ_UNCOMMITTED
• Connection.TRANSACTION_READ_COMMITTED
• Connection.TRANSACTION_REPEATABLE_READ
• Connection.TRANSACTION_SERIALIZABLE
• TransactionDefinition.ISOLATION_READ_UNCOMMITTED
• TransactionDefinition.ISOLATION_READ_COMMITTED
• TransactionDefinition.ISOLATION_REPEATABLE_READ
• TransactionDefinition.ISOLATION_SERIALIZABLE
• TransactionDefinition.getIsolationLevel()
• TransactionSynchronizationManager.getCurrentTransactionIsolationLevel()

getIsolationLevel

@Nullable
protected Integer getIsolationLevel()

Return the statically specified isolation level, or null if none.

doGetConnection

protected Connection doGetConnection(@Nullable
 String username,
 @Nullable
 String password)
                              throws SQLException

Applies the current isolation level value and read-only flag to the returned Connection.

Overrides:

doGetConnection in class UserCredentialsDataSourceAdapter

Parameters:

username - the username to use

password - the password to use

Returns:

the Connection

Throws:

SQLException

See Also:

• getCurrentIsolationLevel()
• getCurrentReadOnlyFlag()

getCurrentIsolationLevel

@Nullable
protected Integer getCurrentIsolationLevel()

Determine the current isolation level: either the transaction's isolation level or a statically defined isolation level.

Returns:

the current isolation level, or null if none

See Also:

• TransactionSynchronizationManager.getCurrentTransactionIsolationLevel()
• setIsolationLevel(int)

getCurrentReadOnlyFlag

@Nullable
protected Boolean getCurrentReadOnlyFlag()

Determine the current read-only flag: by default, the transaction's read-only hint.

Returns:

whether there is a read-only hint for the current scope

See Also:

• TransactionSynchronizationManager.isCurrentTransactionReadOnly()