org.springframework.jdbc.datasource
Class DataSourceUtils

java.lang.Object
  org.springframework.jdbc.datasource.DataSourceUtils

public abstract class DataSourceUtils
extends Object

Helper class that provides static methods for obtaining JDBC Connections from a DataSource. Includes special support for Spring-managed transactional Connections, e.g. managed by DataSourceTransactionManager or JtaTransactionManager.

Used internally by Spring's JdbcTemplate, Spring's JDBC operation objects and the JDBC DataSourceTransactionManager. Can also be used directly in application code.

Author:

Rod Johnson, Juergen Hoeller

See Also:

getConnection(javax.sql.DataSource), releaseConnection(java.sql.Connection, javax.sql.DataSource), DataSourceTransactionManager, JtaTransactionManager, TransactionSynchronizationManager

Field Summary

static int

CONNECTION_SYNCHRONIZATION_ORDER Order value for TransactionSynchronization objects that clean up JDBC Connections.

Constructor Summary

DataSourceUtils()

Method Summary

static void	applyTransactionTimeout(Statement stmt, DataSource dataSource) Apply the current transaction timeout, if any, to the given JDBC Statement object.
static void	closeConnectionIfNecessary(Connection con, DataSource dataSource) Deprecated. in favor of releaseConnection
static Connection	doGetConnection(DataSource dataSource) Actually obtain a JDBC Connection for the given DataSource.
static void	doReleaseConnection(Connection con, DataSource dataSource) Actually release a JDBC Connection for the given DataSource.
static Connection	getConnection(DataSource dataSource) Obtain a Connection from the given DataSource.
static Connection	getTargetConnection(Connection con) Return the innermost target Connection of the given Connection.
static Integer	prepareConnectionForTransaction(Connection con, TransactionDefinition definition) Prepare the given Connection with the given transaction semantics.
static void	releaseConnection(Connection con, DataSource dataSource) Close the given Connection, created via the given DataSource, if it is not managed externally (that is, not bound to the thread).
static void	resetConnectionAfterTransaction(Connection con, Integer previousIsolationLevel) Reset the given Connection after a transaction, regarding read-only flag and isolation level.

Methods inherited from class java.lang.Object

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

Field Detail

CONNECTION_SYNCHRONIZATION_ORDER

public static final int CONNECTION_SYNCHRONIZATION_ORDER

Order value for TransactionSynchronization objects that clean up JDBC Connections.

See Also:

Constant Field Values

Constructor Detail

DataSourceUtils

public DataSourceUtils()

Method Detail

getConnection

public static Connection getConnection(DataSource dataSource)
                                throws CannotGetJdbcConnectionException

Obtain a Connection from the given DataSource. Translates any SQLException into the Spring hierarchy of unchecked generic data access exceptions, simplifying calling code and making any exception that is thrown more meaningful.

Is aware of a corresponding Connection bound to the current thread, for example when using DataSourceTransactionManager. Will bind a Connection to the thread if transaction synchronization is active, e.g. when running within a JTA transaction).

Parameters:

dataSource - DataSource to get Connection from

Returns:

a JDBC Connection from the given DataSource

Throws:

CannotGetJdbcConnectionException - if the attempt to get a Connection failed

See Also:

releaseConnection(java.sql.Connection, javax.sql.DataSource)

doGetConnection

public static Connection doGetConnection(DataSource dataSource)
                                  throws SQLException

Actually obtain a JDBC Connection for the given DataSource. Same as getConnection(javax.sql.DataSource), but throwing the original SQLException.

Is aware of a corresponding Connection bound to the current thread, for example when using DataSourceTransactionManager. Will bind a Connection to the thread if transaction synchronization is active (e.g. if in a JTA transaction).

Directly accessed by TransactionAwareDataSourceProxy.

Parameters:

dataSource - DataSource to get Connection from

Returns:

a JDBC Connection from the given DataSource

Throws:

SQLException - if thrown by JDBC methods

See Also:

doReleaseConnection(java.sql.Connection, javax.sql.DataSource)

prepareConnectionForTransaction

public static Integer prepareConnectionForTransaction(Connection con,
                                                      TransactionDefinition definition)
                                               throws SQLException

Prepare the given Connection with the given transaction semantics.

Parameters:

con - the Connection to prepare

definition - the transaction definition to apply

Returns:

the previous isolation level, if any

Throws:

SQLException - if thrown by JDBC methods

See Also:

resetConnectionAfterTransaction(java.sql.Connection, java.lang.Integer)

resetConnectionAfterTransaction

public static void resetConnectionAfterTransaction(Connection con,
                                                   Integer previousIsolationLevel)

Reset the given Connection after a transaction, regarding read-only flag and isolation level.

Parameters:

con - the Connection to reset

previousIsolationLevel - the isolation level to restore, if any

See Also:

prepareConnectionForTransaction(java.sql.Connection, org.springframework.transaction.TransactionDefinition)

applyTransactionTimeout

public static void applyTransactionTimeout(Statement stmt,
                                           DataSource dataSource)
                                    throws SQLException

Apply the current transaction timeout, if any, to the given JDBC Statement object.

Parameters:

stmt - the JDBC Statement object

dataSource - DataSource that the Connection came from

Throws:

SQLException - if thrown by JDBC methods

See Also:

Statement.setQueryTimeout(int)

closeConnectionIfNecessary

public static void closeConnectionIfNecessary(Connection con,
                                              DataSource dataSource)

Deprecated. in favor of releaseConnection

Close the given Connection if necessary, i.e. if it is not bound to the thread and it is not created by a SmartDataSource returning shouldClose=false.

See Also:

releaseConnection(java.sql.Connection, javax.sql.DataSource)

releaseConnection

public static void releaseConnection(Connection con,
                                     DataSource dataSource)

Close the given Connection, created via the given DataSource, if it is not managed externally (that is, not bound to the thread).

Parameters:

con - the Connection to close if necessary (if this is null, the call will be ignored)

dataSource - the DataSource that the Connection was obtained from (may be null)

See Also:

getConnection(javax.sql.DataSource), SmartDataSource.shouldClose(java.sql.Connection)

doReleaseConnection

public static void doReleaseConnection(Connection con,
                                       DataSource dataSource)
                                throws SQLException

Actually release a JDBC Connection for the given DataSource. Same as releaseConnection(java.sql.Connection, javax.sql.DataSource), but throwing the original SQLException.

Directly accessed by TransactionAwareDataSourceProxy.

Parameters:

con - the Connection to close if necessary (if this is null, the call will be ignored)

dataSource - the DataSource that the Connection was obtained from (may be null)

Throws:

SQLException - if thrown by JDBC methods

See Also:

doGetConnection(javax.sql.DataSource), TransactionAwareDataSourceProxy

getTargetConnection

public static Connection getTargetConnection(Connection con)

Return the innermost target Connection of the given Connection. If the given Connection is a proxy, it will be unwrapped until a non-proxy Connection is found. Else, the passed-in Connection will be returned as-is.

Parameters:

con - the Connection proxy to unwrap

Returns:

the innermost target Connection, or the passed-in one if no proxy

See Also:

ConnectionProxy.getTargetConnection()