Package io.micronaut.transaction.support

Class TransactionSynchronizationManager

java.lang.Object

io.micronaut.transaction.support.TransactionSynchronizationManager

public abstract class TransactionSynchronizationManager
extends Object

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 AbstractSynchronousTransactionManager, and thus by all standard transaction managers.

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.

Since:

02.06.2003

Author:

Juergen Hoeller

See Also:

• isSynchronizationActive()
• registerSynchronization(io.micronaut.transaction.support.TransactionSynchronization)
• TransactionSynchronization
• AbstractSynchronousStateTransactionManager.setTransactionSynchronization(io.micronaut.transaction.support.AbstractSynchronousStateTransactionManager.Synchronization)

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	TransactionSynchronizationManager.TransactionSynchronizationState	The synchronization state.
static interface	TransactionSynchronizationManager.TransactionSynchronizationStateOp	The transaction synchronization state autocloseable operation.

Field Summary

Fields

Modifier and Type	Field	Description
static final Object	DEFAULT_STATE_KEY

Constructor Summary

Constructors

Constructor	Description
TransactionSynchronizationManager()

Method Summary

Modifier and Type	Method	Description
static void	bindResource(Object key, Object value)	Bind the given resource for the given key to the current thread.
static void	bindSynchronousTransactionState(Object key, SynchronousTransactionState state)
static <T> CompletionStage<T>	decorateCompletionStage(TransactionSynchronizationManager.TransactionSynchronizationState state, Supplier<CompletionStage<T>> supplier)	Decorate completion stage supplier with the transaction state.
static <T> Supplier<T>	decorateToPropagateState(Supplier<T> supplier)	Decorate the supplier with possible propagated state in thread-local.
static TransactionSynchronizationManager.TransactionSynchronizationState	getOrCreateState()	Get existing or create new associated state.
static SynchronousTransactionState	getRequiredSynchronousTransactionState(Object key)
static Object	getResource(Object key)	Retrieve a resource for the given key that is bound to the current thread.
static Map<Object,Object>	getResourceMap()	Return all resources that are bound to the current thread.
static <T> T	getResourceOrDefault(Object key, T defaultValue)
static TransactionSynchronizationManager.TransactionSynchronizationState	getState()	Get the existing state.
static SynchronousTransactionState	getSynchronousTransactionState(Object key)
static SynchronousTransactionState	getSynchronousTransactionStateOrCreate(Object key, Supplier<SynchronousTransactionState> creator)
static boolean	hasResource(Object key)	Check if there is a resource for the given key bound to the current thread.
static boolean	isSynchronizationActive()	Deprecated. use getSynchronousTransactionState(Object)
static void	rebindResource(Object key, Object value)
static void	registerSynchronization(TransactionSynchronization synchronization)	Deprecated. use getSynchronousTransactionState(Object)
static void	setState(TransactionSynchronizationManager.TransactionSynchronizationState state)	Restore the state from the thread local.
static Object	unbindResource(Object key)	Unbind a resource for the given key from the current thread.
static Object	unbindResourceIfPossible(Object key)	Unbind a resource for the given key from the current thread.
static SynchronousTransactionState	unbindSynchronousTransactionState(Object key)
static TransactionSynchronizationManager.TransactionSynchronizationStateOp	withGuardedState()	Execute provided supplier with setup state in the thread-local.
static TransactionSynchronizationManager.TransactionSynchronizationStateOp	withState(TransactionSynchronizationManager.TransactionSynchronizationState state)	Execute provided supplier with setup state in the thread-local.
static <T> T	withState(TransactionSynchronizationManager.TransactionSynchronizationState state, Supplier<T> supplier)	Execute provided supplier with setup state in the thread-local.

Methods inherited from class java.lang.Object

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

Field Details

DEFAULT_STATE_KEY

public static final Object DEFAULT_STATE_KEY

Constructor Details

TransactionSynchronizationManager

public TransactionSynchronizationManager()

Method Details

getResourceMap

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:

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(java.lang.Object)

hasResource

public static boolean hasResource(Object key)

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

Parameters:

key - the key to check (usually the resource factory)

Returns:

if there is a value bound to the current thread

See Also:

• ResourceTransactionManager.getResourceFactory()

getResource

@Nullable
public static Object getResource(Object key)

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

Parameters:

key - the key to check (usually the resource factory)

Returns:

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

See Also:

• ResourceTransactionManager.getResourceFactory()

getResourceOrDefault

@NonNull
public static <T> T getResourceOrDefault(Object key,
 @NonNull
 T defaultValue)

bindResource

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

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

Parameters:

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

value - the value to bind (usually the active resource object)

Throws:

IllegalStateException - if there is already a value bound to the thread

See Also:

• ResourceTransactionManager.getResourceFactory()

rebindResource

public static void rebindResource(Object key,
 Object value)
                           throws IllegalStateException

Throws:

IllegalStateException

unbindResource

public static Object unbindResource(Object key)
                             throws IllegalStateException

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

Parameters:

key - the key to unbind (usually the resource factory)

Returns:

the previously bound value (usually the active resource object)

Throws:

IllegalStateException - if there is no value bound to the thread

See Also:

• ResourceTransactionManager.getResourceFactory()

unbindResourceIfPossible

@Nullable
public static Object unbindResourceIfPossible(Object key)

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

Parameters:

key - the key to unbind (usually the resource factory)

Returns:

the previously bound value, or null if none bound

bindSynchronousTransactionState

public static void bindSynchronousTransactionState(@NonNull
 Object key,
 @NonNull
 SynchronousTransactionState state)

unbindSynchronousTransactionState

public static SynchronousTransactionState unbindSynchronousTransactionState(Object key)
                                                                     throws IllegalStateException

Throws:

IllegalStateException

getSynchronousTransactionState

@Nullable
public static SynchronousTransactionState getSynchronousTransactionState(@NonNull
 Object key)

getRequiredSynchronousTransactionState

@NonNull
public static SynchronousTransactionState getRequiredSynchronousTransactionState(@NonNull
 Object key)

getSynchronousTransactionStateOrCreate

@NonNull
public static SynchronousTransactionState getSynchronousTransactionStateOrCreate(@NonNull
 Object key,
 Supplier<SynchronousTransactionState> creator)

isSynchronizationActive

@Deprecated
public static boolean isSynchronizationActive()

Deprecated.

use getSynchronousTransactionState(Object)

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

Returns:

True if a synchronization is active

See Also:

• registerSynchronization(io.micronaut.transaction.support.TransactionSynchronization)

registerSynchronization

@Deprecated
public static void registerSynchronization(TransactionSynchronization synchronization)
                                    throws IllegalStateException

Deprecated.

use getSynchronousTransactionState(Object)

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

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

Parameters:

synchronization - the synchronization object to register

Throws:

IllegalStateException - if transaction synchronization is not active

See Also:

• Ordered

getState

@Internal
@Nullable
public static TransactionSynchronizationManager.TransactionSynchronizationState getState()

Get the existing state.

Returns:

The state

Since:

3.3

getOrCreateState

@Internal
@NonNull
public static TransactionSynchronizationManager.TransactionSynchronizationState getOrCreateState()

Get existing or create new associated state.

Returns:

The state

Since:

3.3

setState

@Internal
public static void setState(@Nullable
 TransactionSynchronizationManager.TransactionSynchronizationState state)

Restore the state from the thread local.

Parameters:

state - The state

Since:

3.3

withState

@Internal
public static <T> T withState(@Nullable
 TransactionSynchronizationManager.TransactionSynchronizationState state,
 Supplier<T> supplier)

Execute provided supplier with setup state in the thread-local. Afterwards update the state with the modifications done to it.

Type Parameters:

T - The supplied type

Parameters:

state - The state

supplier - The supplier to be executed

Returns:

The suppler return value

Since:

3.4.0

decorateCompletionStage

@Internal
public static <T> CompletionStage<T> decorateCompletionStage(@Nullable
 TransactionSynchronizationManager.TransactionSynchronizationState state,
 Supplier<CompletionStage<T>> supplier)

Decorate completion stage supplier with the transaction state.

Type Parameters:

T - The supplied type

Parameters:

state - The state

supplier - The supplier to be executed

Returns:

The suppler return value

Since:

3.5.0

withState

@Internal
public static TransactionSynchronizationManager.TransactionSynchronizationStateOp withState(@Nullable
 TransactionSynchronizationManager.TransactionSynchronizationState state)

Execute provided supplier with setup state in the thread-local. Afterwards update the state with the modifications done to it.

Parameters:

state - The state

Returns:

The suppler return value

Since:

3.5.0

withGuardedState

@Internal
public static TransactionSynchronizationManager.TransactionSynchronizationStateOp withGuardedState()

Execute provided supplier with setup state in the thread-local. Make sure the thread-local state is cleanup afterwards.

Returns:

3.5.0

decorateToPropagateState

@Internal
public static <T> Supplier<T> decorateToPropagateState(Supplier<T> supplier)

Decorate the supplier with possible propagated state in thread-local.

It's used to propagated TX state down to the async functions.

Type Parameters:

T - The supplied type

Parameters:

supplier - The supplier to be decorated

Returns:

The decorated supplier

Since:

3.4.0