org.springframework.transaction

Interface TransactionDefinition

All Known Subinterfaces:

TransactionAttribute

All Known Implementing Classes:

DefaultTransactionAttribute, DefaultTransactionDefinition, DelegatingTransactionAttribute, DelegatingTransactionDefinition, RuleBasedTransactionAttribute, TransactionTemplate

public interface TransactionDefinition

Interface that defines Spring-compliant transaction properties. Based on the propagation behavior definitions analogous to EJB CMT attributes.

Note that isolation level and timeout settings will not get applied unless an actual new transaction gets started. As only PROPAGATION_REQUIRED, PROPAGATION_REQUIRES_NEW and PROPAGATION_NESTED can cause that, it usually doesn't make sense to specify those settings in other cases. Furthermore, be aware that not all transaction managers will support those advanced features and thus might throw corresponding exceptions when given non-default values.

The read-only flag applies to any transaction context, whether backed by an actual resource transaction or operating non-transactionally at the resource level. In the latter case, the flag will only apply to managed resources within the application, such as a Hibernate Session.

Since:

08.05.2003

Author:

Juergen Hoeller

See Also:

PlatformTransactionManager.getTransaction(TransactionDefinition), DefaultTransactionDefinition, TransactionAttribute

Field Summary

Fields

Modifier and Type	Field and Description
static int	ISOLATION_DEFAULT Use the default isolation level of the underlying datastore.
static int	ISOLATION_READ_COMMITTED Indicates that dirty reads are prevented; non-repeatable reads and phantom reads can occur.
static int	ISOLATION_READ_UNCOMMITTED Indicates that dirty reads, non-repeatable reads and phantom reads can occur.
static int	ISOLATION_REPEATABLE_READ Indicates that dirty reads and non-repeatable reads are prevented; phantom reads can occur.
static int	ISOLATION_SERIALIZABLE Indicates that dirty reads, non-repeatable reads and phantom reads are prevented.
static int	PROPAGATION_MANDATORY Support a current transaction; throw an exception if no current transaction exists.
static int	PROPAGATION_NESTED Execute within a nested transaction if a current transaction exists, behave like PROPAGATION_REQUIRED else.
static int	PROPAGATION_NEVER Do not support a current transaction; throw an exception if a current transaction exists.
static int	PROPAGATION_NOT_SUPPORTED Do not support a current transaction; rather always execute non-transactionally.
static int	PROPAGATION_REQUIRED Support a current transaction; create a new one if none exists.
static int	PROPAGATION_REQUIRES_NEW Create a new transaction, suspending the current transaction if one exists.
static int	PROPAGATION_SUPPORTS Support a current transaction; execute non-transactionally if none exists.
static int	TIMEOUT_DEFAULT Use the default timeout of the underlying transaction system, or none if timeouts are not supported.

Method Summary

Modifier and Type	Method and Description
int	getIsolationLevel() Return the isolation level.
String	getName() Return the name of this transaction.
int	getPropagationBehavior() Return the propagation behavior.
int	getTimeout() Return the transaction timeout.
boolean	isReadOnly() Return whether to optimize as a read-only transaction.

Field Detail

PROPAGATION_REQUIRED

static final int PROPAGATION_REQUIRED

Support a current transaction; create a new one if none exists. Analogous to the EJB transaction attribute of the same name.

This is typically the default setting of a transaction definition, and typically defines a transaction synchronization scope.

See Also:

Constant Field Values

PROPAGATION_SUPPORTS

static final int PROPAGATION_SUPPORTS

Support a current transaction; execute non-transactionally if none exists. Analogous to the EJB transaction attribute of the same name.

NOTE: For transaction managers with transaction synchronization, PROPAGATION_SUPPORTS is slightly different from no transaction at all, as it defines a transaction scope that synchronization might apply to. As a consequence, the same resources (a JDBC Connection, a Hibernate Session, etc) will be shared for the entire specified scope. Note that the exact behavior depends on the actual synchronization configuration of the transaction manager!

In general, use PROPAGATION_SUPPORTS with care! In particular, do not rely on PROPAGATION_REQUIRED or PROPAGATION_REQUIRES_NEW within a PROPAGATION_SUPPORTS scope (which may lead to synchronization conflicts at runtime). If such nesting is unavoidable, make sure to configure your transaction manager appropriately (typically switching to "synchronization on actual transaction").

See Also:

AbstractPlatformTransactionManager.setTransactionSynchronization(int), AbstractPlatformTransactionManager.SYNCHRONIZATION_ON_ACTUAL_TRANSACTION, Constant Field Values

PROPAGATION_MANDATORY

static final int PROPAGATION_MANDATORY

Support a current transaction; throw an exception if no current transaction exists. Analogous to the EJB transaction attribute of the same name.

Note that transaction synchronization within a PROPAGATION_MANDATORY scope will always be driven by the surrounding transaction.

See Also:

Constant Field Values

PROPAGATION_REQUIRES_NEW

static final int PROPAGATION_REQUIRES_NEW

Create a new transaction, suspending the current transaction if one exists. Analogous to the EJB transaction attribute of the same name.

NOTE: Actual transaction suspension will not work out-of-the-box on all transaction managers. This in particular applies to JtaTransactionManager, which requires the javax.transaction.TransactionManager to be made available it to it (which is server-specific in standard J2EE).

A PROPAGATION_REQUIRES_NEW scope always defines its own transaction synchronizations. Existing synchronizations will be suspended and resumed appropriately.

See Also:

JtaTransactionManager.setTransactionManager(javax.transaction.TransactionManager), Constant Field Values

PROPAGATION_NOT_SUPPORTED

static final int PROPAGATION_NOT_SUPPORTED

Do not support a current transaction; rather always execute non-transactionally. Analogous to the EJB transaction attribute of the same name.

NOTE: Actual transaction suspension will not work out-of-the-box on all transaction managers. This in particular applies to JtaTransactionManager, which requires the javax.transaction.TransactionManager to be made available it to it (which is server-specific in standard J2EE).

Note that transaction synchronization is not available within a PROPAGATION_NOT_SUPPORTED scope. Existing synchronizations will be suspended and resumed appropriately.

See Also:

JtaTransactionManager.setTransactionManager(javax.transaction.TransactionManager), Constant Field Values

PROPAGATION_NEVER

static final int PROPAGATION_NEVER

Do not support a current transaction; throw an exception if a current transaction exists. Analogous to the EJB transaction attribute of the same name.

Note that transaction synchronization is not available within a PROPAGATION_NEVER scope.

See Also:

Constant Field Values

PROPAGATION_NESTED

static final int PROPAGATION_NESTED

Execute within a nested transaction if a current transaction exists, behave like PROPAGATION_REQUIRED else. There is no analogous feature in EJB.

NOTE: Actual creation of a nested transaction will only work on specific transaction managers. Out of the box, this only applies to the JDBC org.springframework.jdbc.datasource.DataSourceTransactionManager when working on a JDBC 3.0 driver. Some JTA providers might support nested transactions as well.

See Also:

org.springframework.jdbc.datasource.DataSourceTransactionManager, Constant Field Values

ISOLATION_DEFAULT

static final int ISOLATION_DEFAULT

Use the default isolation level of the underlying datastore. All other levels correspond to the JDBC isolation levels.

See Also:

Connection, Constant Field Values

ISOLATION_READ_UNCOMMITTED

static final int ISOLATION_READ_UNCOMMITTED

Indicates that dirty reads, non-repeatable reads and phantom reads can occur.

This level allows a row changed by one transaction to be read by another transaction before any changes in that row have been committed (a "dirty read"). If any of the changes are rolled back, the second transaction will have retrieved an invalid row.

See Also:

Connection.TRANSACTION_READ_UNCOMMITTED, Constant Field Values

ISOLATION_READ_COMMITTED

static final int ISOLATION_READ_COMMITTED

Indicates that dirty reads are prevented; non-repeatable reads and phantom reads can occur.

This level only prohibits a transaction from reading a row with uncommitted changes in it.

See Also:

Connection.TRANSACTION_READ_COMMITTED, Constant Field Values

ISOLATION_REPEATABLE_READ

static final int ISOLATION_REPEATABLE_READ

Indicates that dirty reads and non-repeatable reads are prevented; phantom reads can occur.

This level prohibits a transaction from reading a row with uncommitted changes in it, and it also prohibits the situation where one transaction reads a row, a second transaction alters the row, and the first transaction re-reads the row, getting different values the second time (a "non-repeatable read").

See Also:

Connection.TRANSACTION_REPEATABLE_READ, Constant Field Values

ISOLATION_SERIALIZABLE

static final int ISOLATION_SERIALIZABLE

Indicates that dirty reads, non-repeatable reads and phantom reads are prevented.

This level includes the prohibitions in ISOLATION_REPEATABLE_READ and further prohibits the situation where one transaction reads all rows that satisfy a WHERE condition, a second transaction inserts a row that satisfies that WHERE condition, and the first transaction re-reads for the same condition, retrieving the additional "phantom" row in the second read.

See Also:

Connection.TRANSACTION_SERIALIZABLE, Constant Field Values

TIMEOUT_DEFAULT

static final int TIMEOUT_DEFAULT

Use the default timeout of the underlying transaction system, or none if timeouts are not supported.

See Also:

Constant Field Values

Method Detail

getPropagationBehavior

int getPropagationBehavior()

Return the propagation behavior.

Must return one of the PROPAGATION_XXX constants defined on this interface.

Returns:

the propagation behavior

See Also:

PROPAGATION_REQUIRED, TransactionSynchronizationManager.isActualTransactionActive()

getIsolationLevel

int getIsolationLevel()

Return the isolation level.

Must return one of the ISOLATION_XXX constants defined on this interface.

Only makes sense in combination with PROPAGATION_REQUIRED or PROPAGATION_REQUIRES_NEW.

Note that a transaction manager that does not support custom isolation levels will throw an exception when given any other level than ISOLATION_DEFAULT.

Returns:

the isolation level

getTimeout

int getTimeout()

Return the transaction timeout.

Must return a number of seconds, or TIMEOUT_DEFAULT.

Only makes sense in combination with PROPAGATION_REQUIRED or PROPAGATION_REQUIRES_NEW.

Note that a transaction manager that does not support timeouts will throw an exception when given any other timeout than TIMEOUT_DEFAULT.

Returns:

the transaction timeout

isReadOnly

boolean isReadOnly()

Return whether to optimize as a read-only transaction.

The read-only flag applies to any transaction context, whether backed by an actual resource transaction (PROPAGATION_REQUIRED/PROPAGATION_REQUIRES_NEW) or operating non-transactionally at the resource level (PROPAGATION_SUPPORTS). In the latter case, the flag will only apply to managed resources within the application, such as a Hibernate Session. << *

This just serves as a hint for the actual transaction subsystem; it will not necessarily cause failure of write access attempts. A transaction manager which cannot interpret the read-only hint will not throw an exception when asked for a read-only transaction.

Returns:

true if the transaction is to be optimized as read-only

See Also:

TransactionSynchronization.beforeCommit(boolean), TransactionSynchronizationManager.isCurrentTransactionReadOnly()

getName

String getName()

Return the name of this transaction. Can be null.

This will be used as the transaction name to be shown in a transaction monitor, if applicable (for example, WebLogic's).

In case of Spring's declarative transactions, the exposed name will be the fully-qualified class name + "." + method name (by default).

Returns:

the name of this transaction

See Also:

TransactionAspectSupport, TransactionSynchronizationManager.getCurrentTransactionName()