Top Description Fields Constructors Methods
org.springframework.transaction.support

public abstract Class TransactionSynchronizationManager

extends Object
Class Inheritance
Imports
java.util.ArrayList, .Collections, .HashMap, .LinkedHashSet, .List, .Map, .Set, org.springframework.core.NamedThreadLocal, .OrderComparator, org.springframework.lang.Nullable, org.springframework.util.Assert
Central delegate that manages resources and transaction synchronizations per thread. To be used by resource management code but not by typical application code.

Supports one resource per key without overwriting, that is, a resource needs to be removed before a new one can be set for the same key. Supports a list of transaction synchronizations if synchronization is active.

Resource management code should check for thread-bound resources, e.g. JDBC Connections or Hibernate Sessions, via getResource. Such code is normally not supposed to bind resources to threads, as this is the responsibility of transaction managers. A further option is to lazily bind on first use if transaction synchronization is active, for performing transactions that span an arbitrary number of resources.

Transaction synchronization must be activated and deactivated by a transaction manager via initSynchronization() and clearSynchronization(). This is automatically supported by AbstractPlatformTransactionManager, and thus by all standard Spring transaction managers, such as org.springframework.transaction.jta.JtaTransactionManager and org.springframework.jdbc.datasource.DataSourceTransactionManager.

Resource management code should only register synchronizations when this manager is active, which can be checked via isSynchronizationActive; it should perform immediate resource cleanup else. If transaction synchronization isn't active, there is either no current transaction, or the transaction manager doesn't support transaction synchronization.

Synchronization is for example used to always return the same resources within a JTA transaction, e.g. a JDBC Connection or a Hibernate Session for any given DataSource or SessionFactory, respectively.

Author
Juergen Hoeller
Since
02.06.2003
See Also
isSynchronizationActive, registerSynchronization, TransactionSynchronization, AbstractPlatformTransactionManager#setTransactionSynchronization, org.springframework.transaction.jta.JtaTransactionManager, org.springframework.jdbc.datasource.DataSourceTransactionManager, org.springframework.jdbc.datasource.DataSourceUtils#getConnection

Field Summary

Modifier and TypeField and Description
private static final ThreadLocal<Boolean>
actualTransactionActive

private static final ThreadLocal<Integer>
currentTransactionIsolationLevel

private static final ThreadLocal<String>
currentTransactionName

private static final ThreadLocal<Boolean>
currentTransactionReadOnly

private static final ThreadLocal<Map<Object, Object>>
resources

private static final ThreadLocal<Set<TransactionSynchronization>>
synchronizations

Constructor Summary

AccessConstructor and Description
public
TransactionSynchronizationManager()

Method Summary

Modifier and TypeMethod and Description
public static void
bindResource(Object
the key to bind the value to (usually the resource factory)
key, Object
the value to bind (usually the active resource object)
value)

Bind the given resource for the given key to the current thread.

public static void
clear()

Clear the entire transaction synchronization state for the current thread: registered synchronizations as well as the various transaction characteristics.

public static void
clearSynchronization()

Deactivate transaction synchronization for the current thread.

private static Object
doGetResource(Object actualKey)

Actually check the value of the resource that is bound for the given key.

private static Object
doUnbindResource(Object actualKey)

Actually remove the value of the resource that is bound for the given key.

public static Integer

Returns:

the currently exposed isolation level, according to the JDBC Connection constants (equivalent to the corresponding Spring TransactionDefinition constants), or null if none
getCurrentTransactionIsolationLevel()

Return the isolation level for the current transaction, if any.

public static String
getCurrentTransactionName()

Return the name of the current transaction, or null if none set.

public static Object

Returns:

a value bound to the current thread (usually the active resource object), or null if none
getResource(Object
the key to check (usually the resource factory)
key)

Retrieve a resource for the given key that is bound to the current thread.

public static Map<Object, Object>

Returns:

a Map with resource keys (usually the resource factory) and resource values (usually the active resource object), or an empty Map if there are currently no resources bound
getResourceMap()

Return all resources that are bound to the current thread.

public static List<TransactionSynchronization>

Returns:

unmodifiable List of TransactionSynchronization instances
getSynchronizations()

Return an unmodifiable snapshot list of all registered synchronizations for the current thread.

public static boolean

Returns:

if there is a value bound to the current thread
hasResource(Object
the key to check (usually the resource factory)
key)

Check if there is a resource for the given key bound to the current thread.

public static void
initSynchronization()

Activate transaction synchronization for the current thread.

public static boolean
isActualTransactionActive()

Return whether there currently is an actual transaction active.

public static boolean
isCurrentTransactionReadOnly()

Return whether the current transaction is marked as read-only.

public static boolean
isSynchronizationActive()

Return if transaction synchronization is active for the current thread.

public static void
registerSynchronization(TransactionSynchronization
the synchronization object to register
synchronization)

Register a new transaction synchronization for the current thread.

public static void
setActualTransactionActive(boolean
true to mark the current thread as being associated with an actual transaction; false to reset that marker
active)

Expose whether there currently is an actual transaction active.

public static void
setCurrentTransactionIsolationLevel(Integer
the isolation level to expose, according to the JDBC Connection constants (equivalent to the corresponding Spring TransactionDefinition constants), or null to reset it
isolationLevel)

Expose an isolation level for the current transaction.

public static void
setCurrentTransactionName(String
the name of the transaction, or null to reset it
name)

Expose the name of the current transaction, if any.

public static void
setCurrentTransactionReadOnly(boolean
true to mark the current transaction as read-only; false to reset such a read-only marker
readOnly)

Expose a read-only flag for the current transaction.

public static Object

Returns:

the previously bound value (usually the active resource object)
unbindResource(Object
the key to unbind (usually the resource factory)
key)

Unbind a resource for the given key from the current thread.

public static Object

Returns:

the previously bound value, or null if none bound
unbindResourceIfPossible(Object
the key to unbind (usually the resource factory)
key)

Unbind a resource for the given key from the current thread.

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

actualTransactionActiveback to summary
private static final ThreadLocal<Boolean> actualTransactionActive
currentTransactionIsolationLevelback to summary
private static final ThreadLocal<Integer> currentTransactionIsolationLevel
currentTransactionNameback to summary
private static final ThreadLocal<String> currentTransactionName
currentTransactionReadOnlyback to summary
private static final ThreadLocal<Boolean> currentTransactionReadOnly
resourcesback to summary
private static final ThreadLocal<Map<Object, Object>> resources
synchronizationsback to summary
private static final ThreadLocal<Set<TransactionSynchronization>> synchronizations

Constructor Detail

TransactionSynchronizationManagerback to summary
public TransactionSynchronizationManager()

Method Detail

bindResourceback to summary
public static void bindResource(Object key, Object value) throws IllegalStateException

Bind the given resource for the given key to the current thread.

Parameters
key:Object

the key to bind the value to (usually the resource factory)

value:Object

the value to bind (usually the active resource object)

Exceptions
IllegalStateException:
if there is already a value bound to the thread
See Also
ResourceTransactionManager#getResourceFactory()
clearback to summary
public static void clear()

Clear the entire transaction synchronization state for the current thread: registered synchronizations as well as the various transaction characteristics.

See Also
clearSynchronization(), setCurrentTransactionName, setCurrentTransactionReadOnly, setCurrentTransactionIsolationLevel, setActualTransactionActive
clearSynchronizationback to summary
public static void clearSynchronization() throws IllegalStateException

Deactivate transaction synchronization for the current thread. Called by the transaction manager on transaction cleanup.

Exceptions
IllegalStateException:
if synchronization is not active
doGetResourceback to summary
private static Object doGetResource(Object actualKey)

Actually check the value of the resource that is bound for the given key.

Annotations
@Nullable
doUnbindResourceback to summary
private static Object doUnbindResource(Object actualKey)

Actually remove the value of the resource that is bound for the given key.

Annotations
@Nullable
getCurrentTransactionIsolationLevelback to summary
public static Integer getCurrentTransactionIsolationLevel()

Return the isolation level for the current transaction, if any. To be called by resource management code when preparing a newly created resource (for example, a JDBC Connection).

Returns:Integer

the currently exposed isolation level, according to the JDBC Connection constants (equivalent to the corresponding Spring TransactionDefinition constants), or null if none

Annotations
@Nullable
See Also
java.sql.Connection#TRANSACTION_READ_UNCOMMITTED, java.sql.Connection#TRANSACTION_READ_COMMITTED, java.sql.Connection#TRANSACTION_REPEATABLE_READ, java.sql.Connection#TRANSACTION_SERIALIZABLE, org.springframework.transaction.TransactionDefinition#ISOLATION_READ_UNCOMMITTED, org.springframework.transaction.TransactionDefinition#ISOLATION_READ_COMMITTED, org.springframework.transaction.TransactionDefinition#ISOLATION_REPEATABLE_READ, org.springframework.transaction.TransactionDefinition#ISOLATION_SERIALIZABLE, org.springframework.transaction.TransactionDefinition#getIsolationLevel()
getCurrentTransactionNameback to summary
public static String getCurrentTransactionName()

Return the name of the current transaction, or null if none set. To be called by resource management code for optimizations per use case, for example to optimize fetch strategies for specific named transactions.

Annotations
@Nullable
See Also
org.springframework.transaction.TransactionDefinition#getName()
getResourceback to summary
public static Object getResource(Object key)

Retrieve a resource for the given key that is bound to the current thread.

Parameters
key:Object

the key to check (usually the resource factory)

Returns:Object

a value bound to the current thread (usually the active resource object), or null if none

Annotations
@Nullable
See Also
ResourceTransactionManager#getResourceFactory()
getResourceMapback to summary
public static Map<Object, Object> getResourceMap()

Return all resources that are bound to the current thread.

Mainly for debugging purposes. Resource managers should always invoke hasResource for a specific resource key that they are interested in.

Returns:Map<Object, Object>

a Map with resource keys (usually the resource factory) and resource values (usually the active resource object), or an empty Map if there are currently no resources bound

See Also
hasResource
getSynchronizationsback to summary
public static List<TransactionSynchronization> getSynchronizations() throws IllegalStateException

Return an unmodifiable snapshot list of all registered synchronizations for the current thread.

Returns:List<TransactionSynchronization>

unmodifiable List of TransactionSynchronization instances

Exceptions
IllegalStateException:
if synchronization is not active
See Also
TransactionSynchronization
hasResourceback to summary
public static boolean hasResource(Object key)

Check if there is a resource for the given key bound to the current thread.

Parameters
key:Object

the key to check (usually the resource factory)

Returns:boolean

if there is a value bound to the current thread

See Also
ResourceTransactionManager#getResourceFactory()
initSynchronizationback to summary
public static void initSynchronization() throws IllegalStateException

Activate transaction synchronization for the current thread. Called by a transaction manager on transaction begin.

Exceptions
IllegalStateException:
if synchronization is already active
isActualTransactionActiveback to summary
public static boolean isActualTransactionActive()

Return whether there currently is an actual transaction active. This indicates whether the current thread is associated with an actual transaction rather than just with active transaction synchronization.

To be called by resource management code that wants to differentiate between active transaction synchronization (with or without a backing resource transaction; also on PROPAGATION_SUPPORTS) and an actual transaction being active (with a backing resource transaction; on PROPAGATION_REQUIRED, PROPAGATION_REQUIRES_NEW, etc).

See Also
isSynchronizationActive()
isCurrentTransactionReadOnlyback to summary
public static boolean isCurrentTransactionReadOnly()

Return whether the current transaction is marked as read-only. To be called by resource management code when preparing a newly created resource (for example, a Hibernate Session).

Note that transaction synchronizations receive the read-only flag as argument for the beforeCommit callback, to be able to suppress change detection on commit. The present method is meant to be used for earlier read-only checks, for example to set the flush mode of a Hibernate Session to "FlushMode.MANUAL" upfront.

See Also
org.springframework.transaction.TransactionDefinition#isReadOnly(), TransactionSynchronization#beforeCommit(boolean)
isSynchronizationActiveback to summary
public static boolean isSynchronizationActive()

Return if transaction synchronization is active for the current thread. Can be called before register to avoid unnecessary instance creation.

See Also
registerSynchronization
registerSynchronizationback to summary
public static void registerSynchronization(TransactionSynchronization synchronization) throws IllegalStateException

Register a new transaction synchronization for the current thread. Typically called by resource management code.

Note that synchronizations can implement the org.springframework.core.Ordered interface. They will be executed in an order according to their order value (if any).

Parameters
synchronization:TransactionSynchronization

the synchronization object to register

Exceptions
IllegalStateException:
if transaction synchronization is not active
See Also
org.springframework.core.Ordered
setActualTransactionActiveback to summary
public static void setActualTransactionActive(boolean active)

Expose whether there currently is an actual transaction active. Called by the transaction manager on transaction begin and on cleanup.

Parameters
active:boolean

true to mark the current thread as being associated with an actual transaction; false to reset that marker

setCurrentTransactionIsolationLevelback to summary
public static void setCurrentTransactionIsolationLevel(Integer isolationLevel)

Expose an isolation level for the current transaction. Called by the transaction manager on transaction begin and on cleanup.

Parameters
isolationLevel:Integer

the isolation level to expose, according to the JDBC Connection constants (equivalent to the corresponding Spring TransactionDefinition constants), or null to reset it

See Also
java.sql.Connection#TRANSACTION_READ_UNCOMMITTED, java.sql.Connection#TRANSACTION_READ_COMMITTED, java.sql.Connection#TRANSACTION_REPEATABLE_READ, java.sql.Connection#TRANSACTION_SERIALIZABLE, org.springframework.transaction.TransactionDefinition#ISOLATION_READ_UNCOMMITTED, org.springframework.transaction.TransactionDefinition#ISOLATION_READ_COMMITTED, org.springframework.transaction.TransactionDefinition#ISOLATION_REPEATABLE_READ, org.springframework.transaction.TransactionDefinition#ISOLATION_SERIALIZABLE, org.springframework.transaction.TransactionDefinition#getIsolationLevel()
setCurrentTransactionNameback to summary
public static void setCurrentTransactionName(String name)

Expose the name of the current transaction, if any. Called by the transaction manager on transaction begin and on cleanup.

Parameters
name:String

the name of the transaction, or null to reset it

See Also
org.springframework.transaction.TransactionDefinition#getName()
setCurrentTransactionReadOnlyback to summary
public static void setCurrentTransactionReadOnly(boolean readOnly)

Expose a read-only flag for the current transaction. Called by the transaction manager on transaction begin and on cleanup.

Parameters
readOnly:boolean

true to mark the current transaction as read-only; false to reset such a read-only marker

See Also
org.springframework.transaction.TransactionDefinition#isReadOnly()
unbindResourceback to summary
public static Object unbindResource(Object key) throws IllegalStateException

Unbind a resource for the given key from the current thread.

Parameters
key:Object

the key to unbind (usually the resource factory)

Returns:Object

the previously bound value (usually the active resource object)

Exceptions
IllegalStateException:
if there is no value bound to the thread
See Also
ResourceTransactionManager#getResourceFactory()
unbindResourceIfPossibleback to summary
public static Object unbindResourceIfPossible(Object key)

Unbind a resource for the given key from the current thread.

Parameters
key:Object

the key to unbind (usually the resource factory)

Returns:Object

the previously bound value, or null if none bound

Annotations
@Nullable