org.springframework.jdbc.datasource
Class DataSourceTransactionManager

java.lang.Object
  org.springframework.transaction.support.AbstractPlatformTransactionManager
      org.springframework.jdbc.datasource.DataSourceTransactionManager

All Implemented Interfaces:

Serializable, InitializingBean, PlatformTransactionManager

public class DataSourceTransactionManager
extends AbstractPlatformTransactionManager
implements InitializingBean

PlatformTransactionManager implementation for a single JDBC DataSource. This class is capable of working in any environment with any JDBC driver, as long as the setup uses a JDBC 2.0 Standard Extensions / JDBC 3.0 javax.sql.DataSource as its Connection factory mechanism. Binds a JDBC Connection from the specified DataSource to the current thread, potentially allowing for one thread-bound Connection per DataSource.

Application code is required to retrieve the JDBC Connection via DataSourceUtils.getConnection(DataSource) instead of the standard J2EE-style DataSource.getConnection(). Spring classes such as JdbcTemplate use this strategy implicitly. If not used in combination with this transaction manager, the DataSourceUtils lookup strategy behaves exactly like the native DataSource lookup; it can thus be used in a portable fashion.

Alternatively, you can also allow application code to work with the standard J2EE-style lookup pattern DataSource.getConnection(), for example for legacy code that is not aware of Spring at all. In that case, define a TransactionAwareDataSourceProxy for your target DataSource, and pass that proxy DataSource to your DAOs, which will automatically participate in Spring-managed transactions when accessing it. Note that the DataSourceTransactionManager instance still needs be configured with the specific DataSource that it is supposed to create transactions for.

Supports custom isolation levels, and timeouts which get applied as appropriate JDBC statement timeouts. To support the latter, application code must either use JdbcTemplate, call DataSourceUtils.applyTransactionTimeout(java.sql.Statement, javax.sql.DataSource) for each created JDBC Statement, or go through a TransactionAwareDataSourceProxy which will create timeout-aware JDBC Connections and Statements automatically.

Consider defining a LazyConnectionDataSourceProxy for your target DataSource, pointing both this transaction manager and your DAOs to it. This will lead to optimized handling of "empty" transactions, i.e. of transactions without any JDBC statements executed. A LazyConnectionDataSourceProxy will not fetch an actual JDBC Connection from the target DataSource until a Statement gets executed, lazily applying the specified transaction settings to the target Connection.

On JDBC 3.0, this transaction manager supports nested transactions via the JDBC 3.0 Savepoint mechanism. The "nestedTransactionAllowed" flag defaults to "true", since nested transactions will work without restrictions on JDBC drivers that support savepoints (such as the Oracle JDBC driver).

This transaction manager can be used as a replacement for the JtaTransactionManager in the single resource case, as it does not require a container that supports JTA, typically in combination with a locally defined JDBC DataSource (e.g. a Jakarta Commons DBCP connection pool). Switching between this local strategy and a JTA environment is just a matter of configuration!

Since:

02.05.2003

Author:

Juergen Hoeller

See Also:

AbstractPlatformTransactionManager.setNestedTransactionAllowed(boolean), Savepoint, DataSourceUtils.getConnection(javax.sql.DataSource), DataSourceUtils.applyTransactionTimeout(java.sql.Statement, javax.sql.DataSource), DataSourceUtils.releaseConnection(java.sql.Connection, javax.sql.DataSource), TransactionAwareDataSourceProxy, LazyConnectionDataSourceProxy, JdbcTemplate, org.springframework.jdbc.object, Serialized Form

Field Summary

Fields inherited from class org.springframework.transaction.support.AbstractPlatformTransactionManager

logger, SYNCHRONIZATION_ALWAYS, SYNCHRONIZATION_NEVER, SYNCHRONIZATION_ON_ACTUAL_TRANSACTION

Constructor Summary

DataSourceTransactionManager()
Create a new DataSourceTransactionManager instance.

DataSourceTransactionManager(DataSource dataSource)
Create a new DataSourceTransactionManager instance.

Method Summary

void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected void	doBegin(Object transaction, TransactionDefinition definition) This implementation sets the isolation level but ignores the timeout.
protected void	doCleanupAfterCompletion(Object transaction) Cleanup resources after transaction completion.
protected void	doCommit(DefaultTransactionStatus status) Perform an actual commit of the given transaction.
protected Object	doGetTransaction() Return a transaction object for the current transaction state.
protected void	doResume(Object transaction, Object suspendedResources) Resume the resources of the current transaction.
protected void	doRollback(DefaultTransactionStatus status) Perform an actual rollback of the given transaction.
protected void	doSetRollbackOnly(DefaultTransactionStatus status) Set the given transaction rollback-only.
protected Object	doSuspend(Object transaction) Suspend the resources of the current transaction.
DataSource	getDataSource() Return the JDBC DataSource that this instance manages transactions for.
protected boolean	isExistingTransaction(Object transaction) Check if the given transaction object indicates an existing transaction (that is, a transaction which has already started).
void	setDataSource(DataSource dataSource) Set the JDBC DataSource that this instance should manage transactions for.

Methods inherited from class org.springframework.transaction.support.AbstractPlatformTransactionManager

commit, getTransaction, getTransactionSynchronization, invokeAfterCompletion, isGlobalRollbackOnParticipationFailure, isNestedTransactionAllowed, isRollbackOnCommitFailure, registerAfterCompletionWithExistingTransaction, rollback, setGlobalRollbackOnParticipationFailure, setNestedTransactionAllowed, setRollbackOnCommitFailure, setTransactionSynchronization, setTransactionSynchronizationName, shouldCommitOnGlobalRollbackOnly, useSavepointForNestedTransaction

Methods inherited from class java.lang.Object

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

Constructor Detail

DataSourceTransactionManager

public DataSourceTransactionManager()

Create a new DataSourceTransactionManager instance. A DataSource has to be set to be able to use it.

See Also:

setDataSource(javax.sql.DataSource)

DataSourceTransactionManager

public DataSourceTransactionManager(DataSource dataSource)

Create a new DataSourceTransactionManager instance.

Parameters:

dataSource - JDBC DataSource to manage transactions for

Method Detail

setDataSource

public void setDataSource(DataSource dataSource)

Set the JDBC DataSource that this instance should manage transactions for.

This will typically be a locally defined DataSource, for example a Jakarta Commons DBCP connection pool. Alternatively, you can also drive transactions for a non-XA J2EE DataSource fetched from JNDI. For an XA DataSource, use JtaTransactionManager.

The DataSource specified here should be the target DataSource to manage transactions for, not a TransactionAwareDataSourceProxy. Only data access code may work with TransactionAwareDataSourceProxy, while the transaction manager needs to work on the underlying target DataSource. If there's nevertheless a TransactionAwareDataSourceProxy passed in, it will be unwrapped to extract its target DataSource.

See Also:

TransactionAwareDataSourceProxy, JtaTransactionManager

getDataSource

public DataSource getDataSource()

Return the JDBC DataSource that this instance manages transactions for.

afterPropertiesSet

public void afterPropertiesSet()

Description copied from interface: InitializingBean

Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:

afterPropertiesSet in interface InitializingBean

doGetTransaction

protected Object doGetTransaction()

Description copied from class: AbstractPlatformTransactionManager

Return a transaction object for the current transaction state.

The returned object will usually be specific to the concrete transaction manager implementation, carrying corresponding transaction state in a modifiable fashion. This object will be passed into the other template methods (e.g. doBegin and doCommit), either directly or as part of a DefaultTransactionStatus instance.

The returned object should contain information about any existing transaction, that is, a transaction that has already started before the current getTransaction call on the transaction manager. Consequently, a doGetTransaction implementation will usually look for an existing transaction and store corresponding state in the returned transaction object.

Specified by:

doGetTransaction in class AbstractPlatformTransactionManager

Returns:

the current transaction object

See Also:

AbstractPlatformTransactionManager.doBegin(java.lang.Object, org.springframework.transaction.TransactionDefinition), AbstractPlatformTransactionManager.doCommit(org.springframework.transaction.support.DefaultTransactionStatus), AbstractPlatformTransactionManager.doRollback(org.springframework.transaction.support.DefaultTransactionStatus), DefaultTransactionStatus.getTransaction()

isExistingTransaction

protected boolean isExistingTransaction(Object transaction)

Description copied from class: AbstractPlatformTransactionManager

Check if the given transaction object indicates an existing transaction (that is, a transaction which has already started).

The result will be evaluated according to the specified propagation behavior for the new transaction. An existing transaction might get suspended (in case of PROPAGATION_REQUIRES_NEW), or the new transaction might participate in the existing one (in case of PROPAGATION_REQUIRED).

The default implementation returns false, assuming that participating in existing transactions is generally not supported. Subclasses are of course encouraged to provide such support.

Overrides:

isExistingTransaction in class AbstractPlatformTransactionManager

Parameters:

transaction - transaction object returned by doGetTransaction

Returns:

if there is an existing transaction

See Also:

AbstractPlatformTransactionManager.doGetTransaction()

doBegin

protected void doBegin(Object transaction,
                       TransactionDefinition definition)

This implementation sets the isolation level but ignores the timeout.

Specified by:

doBegin in class AbstractPlatformTransactionManager

Parameters:

transaction - transaction object returned by doGetTransaction

definition - TransactionDefinition instance, describing propagation behavior, isolation level, read-only flag, timeout, and transaction name

doSuspend

protected Object doSuspend(Object transaction)

Description copied from class: AbstractPlatformTransactionManager

Suspend the resources of the current transaction. Transaction synchronization will already have been suspended.

The default implementation throws a TransactionSuspensionNotSupportedException, assuming that transaction suspension is generally not supported.

Overrides:

doSuspend in class AbstractPlatformTransactionManager

Parameters:

transaction - transaction object returned by doGetTransaction

Returns:

an object that holds suspended resources (will be kept unexamined for passing it into doResume)

See Also:

AbstractPlatformTransactionManager.doResume(java.lang.Object, java.lang.Object)

doResume

protected void doResume(Object transaction,
                        Object suspendedResources)

Description copied from class: AbstractPlatformTransactionManager

Resume the resources of the current transaction. Transaction synchronization will be resumed afterwards.

The default implementation throws a TransactionSuspensionNotSupportedException, assuming that transaction suspension is generally not supported.

Overrides:

doResume in class AbstractPlatformTransactionManager

Parameters:

transaction - transaction object returned by doGetTransaction

suspendedResources - the object that holds suspended resources, as returned by doSuspend

See Also:

AbstractPlatformTransactionManager.doSuspend(java.lang.Object)

doCommit

protected void doCommit(DefaultTransactionStatus status)

Description copied from class: AbstractPlatformTransactionManager

Perform an actual commit of the given transaction.

An implementation does not need to check the "new transaction" flag or the rollback-only flag; this will already have been handled before. Usually, a straight commit will be performed on the transaction object contained in the passed-in status.

Specified by:

doCommit in class AbstractPlatformTransactionManager

Parameters:

status - the status representation of the transaction

See Also:

DefaultTransactionStatus.getTransaction()

doRollback

protected void doRollback(DefaultTransactionStatus status)

Description copied from class: AbstractPlatformTransactionManager

Perform an actual rollback of the given transaction.

An implementation does not need to check the "new transaction" flag; this will already have been handled before. Usually, a straight rollback will be performed on the transaction object contained in the passed-in status.

Specified by:

doRollback in class AbstractPlatformTransactionManager

Parameters:

status - the status representation of the transaction

See Also:

DefaultTransactionStatus.getTransaction()

doSetRollbackOnly

protected void doSetRollbackOnly(DefaultTransactionStatus status)

Description copied from class: AbstractPlatformTransactionManager

Set the given transaction rollback-only. Only called on rollback if the current transaction participates in an existing one.

The default implementation throws an IllegalTransactionStateException, assuming that participating in existing transactions is generally not supported. Subclasses are of course encouraged to provide such support.

Overrides:

doSetRollbackOnly in class AbstractPlatformTransactionManager

Parameters:

status - the status representation of the transaction

doCleanupAfterCompletion

protected void doCleanupAfterCompletion(Object transaction)

Description copied from class: AbstractPlatformTransactionManager

Cleanup resources after transaction completion.

Called after doCommit and doRollback execution, on any outcome. The default implementation does nothing.

Should not throw any exceptions but just issue warnings on errors.

Overrides:

doCleanupAfterCompletion in class AbstractPlatformTransactionManager

Parameters:

transaction - transaction object returned by doGetTransaction