类 TransactionSynchronizationManager
- java.lang.Object
- org.springframework.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()
andclearSynchronization()
. This is automatically supported byAbstractPlatformTransactionManager
, and thus by all standard Spring transaction managers, such asJtaTransactionManager
andDataSourceTransactionManager
.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.
- 从以下版本开始:
- 02.06.2003
- 作者:
- Juergen Hoeller
- 另请参阅:
isSynchronizationActive()
,registerSynchronization(org.springframework.transaction.support.TransactionSynchronization)
,TransactionSynchronization
,AbstractPlatformTransactionManager.setTransactionSynchronization(int)
,JtaTransactionManager
,DataSourceTransactionManager
,DataSourceUtils.getConnection(javax.sql.DataSource)
构造器概要
构造器 构造器 说明 TransactionSynchronizationManager()
方法概要
所有方法 静态方法 具体方法 修饰符和类型 方法 说明 static void
bindResource(Object key, Object value)
Bind the given resource for the given key to the current thread.static void
clear()
Clear the entire transaction synchronization state for the current thread: registered synchronizations as well as the various transaction characteristics.static void
clearSynchronization()
Deactivate transaction synchronization for the current thread.static Integer
getCurrentTransactionIsolationLevel()
Return the isolation level for the current transaction, if any.static String
getCurrentTransactionName()
Return the name of the current transaction, ornull
if none set.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 List<TransactionSynchronization>
getSynchronizations()
Return an unmodifiable snapshot list of all registered synchronizations for the current thread.static boolean
hasResource(Object key)
Check if there is a resource for the given key bound to the current thread.static void
initSynchronization()
Activate transaction synchronization for the current thread.static boolean
isActualTransactionActive()
Return whether there currently is an actual transaction active.static boolean
isCurrentTransactionReadOnly()
Return whether the current transaction is marked as read-only.static boolean
isSynchronizationActive()
Return if transaction synchronization is active for the current thread.static void
registerSynchronization(TransactionSynchronization synchronization)
Register a new transaction synchronization for the current thread.static void
setActualTransactionActive(boolean active)
Expose whether there currently is an actual transaction active.static void
setCurrentTransactionIsolationLevel(Integer isolationLevel)
Expose an isolation level for the current transaction.static void
setCurrentTransactionName(String name)
Expose the name of the current transaction, if any.static void
setCurrentTransactionReadOnly(boolean readOnly)
Expose a read-only flag for the current transaction.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.
构造器详细资料
TransactionSynchronizationManager
public TransactionSynchronizationManager()
方法详细资料
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.- 返回:
- 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
- 另请参阅:
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.- 参数:
key
- the key to check (usually the resource factory)- 返回:
- if there is a value bound to the current thread
- 另请参阅:
ResourceTransactionManager.getResourceFactory()
getResource
@Nullable public static Object getResource(Object key)
Retrieve a resource for the given key that is bound to the current thread.- 参数:
key
- the key to check (usually the resource factory)- 返回:
- a value bound to the current thread (usually the active resource object), or
null
if none - 另请参阅:
ResourceTransactionManager.getResourceFactory()
bindResource
public static void bindResource(Object key, Object value) throws IllegalStateException
Bind the given resource for the given key to the current thread.- 参数:
key
- the key to bind the value to (usually the resource factory)value
- the value to bind (usually the active resource object)- 抛出:
IllegalStateException
- if there is already a value bound to the thread- 另请参阅:
ResourceTransactionManager.getResourceFactory()
unbindResource
public static Object unbindResource(Object key) throws IllegalStateException
Unbind a resource for the given key from the current thread.- 参数:
key
- the key to unbind (usually the resource factory)- 返回:
- the previously bound value (usually the active resource object)
- 抛出:
IllegalStateException
- if there is no value bound to the thread- 另请参阅:
ResourceTransactionManager.getResourceFactory()
unbindResourceIfPossible
@Nullable public static Object unbindResourceIfPossible(Object key)
Unbind a resource for the given key from the current thread.- 参数:
key
- the key to unbind (usually the resource factory)- 返回:
- the previously bound value, or
null
if none bound
isSynchronizationActive
public static boolean isSynchronizationActive()
Return if transaction synchronization is active for the current thread. Can be called before register to avoid unnecessary instance creation.
initSynchronization
public static void initSynchronization() throws IllegalStateException
Activate transaction synchronization for the current thread. Called by a transaction manager on transaction begin.- 抛出:
IllegalStateException
- if synchronization is already active
registerSynchronization
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
Ordered
interface. They will be executed in an order according to their order value (if any).- 参数:
synchronization
- the synchronization object to register- 抛出:
IllegalStateException
- if transaction synchronization is not active- 另请参阅:
Ordered
getSynchronizations
public static List<TransactionSynchronization> getSynchronizations() throws IllegalStateException
Return an unmodifiable snapshot list of all registered synchronizations for the current thread.- 返回:
- unmodifiable List of TransactionSynchronization instances
- 抛出:
IllegalStateException
- if synchronization is not active- 另请参阅:
TransactionSynchronization
clearSynchronization
public static void clearSynchronization() throws IllegalStateException
Deactivate transaction synchronization for the current thread. Called by the transaction manager on transaction cleanup.- 抛出:
IllegalStateException
- if synchronization is not active
setCurrentTransactionName
public static void setCurrentTransactionName(@Nullable String name)
Expose the name of the current transaction, if any. Called by the transaction manager on transaction begin and on cleanup.- 参数:
name
- the name of the transaction, ornull
to reset it- 另请参阅:
TransactionDefinition.getName()
getCurrentTransactionName
@Nullable public static String getCurrentTransactionName()
Return the name of the current transaction, ornull
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.
setCurrentTransactionReadOnly
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.- 参数:
readOnly
-true
to mark the current transaction as read-only;false
to reset such a read-only marker- 另请参阅:
TransactionDefinition.isReadOnly()
isCurrentTransactionReadOnly
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.
setCurrentTransactionIsolationLevel
public static void setCurrentTransactionIsolationLevel(@Nullable Integer isolationLevel)
Expose an isolation level for the current transaction. Called by the transaction manager on transaction begin and on cleanup.- 参数:
isolationLevel
- the isolation level to expose, according to the JDBC Connection constants (equivalent to the corresponding Spring TransactionDefinition constants), ornull
to reset it- 另请参阅:
Connection.TRANSACTION_READ_UNCOMMITTED
,Connection.TRANSACTION_READ_COMMITTED
,Connection.TRANSACTION_REPEATABLE_READ
,Connection.TRANSACTION_SERIALIZABLE
,TransactionDefinition.ISOLATION_READ_UNCOMMITTED
,TransactionDefinition.ISOLATION_READ_COMMITTED
,TransactionDefinition.ISOLATION_REPEATABLE_READ
,TransactionDefinition.ISOLATION_SERIALIZABLE
,TransactionDefinition.getIsolationLevel()
getCurrentTransactionIsolationLevel
@Nullable 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).- 返回:
- the currently exposed isolation level, according to the JDBC Connection constants (equivalent to the corresponding Spring TransactionDefinition constants), or
null
if none - 另请参阅:
Connection.TRANSACTION_READ_UNCOMMITTED
,Connection.TRANSACTION_READ_COMMITTED
,Connection.TRANSACTION_REPEATABLE_READ
,Connection.TRANSACTION_SERIALIZABLE
,TransactionDefinition.ISOLATION_READ_UNCOMMITTED
,TransactionDefinition.ISOLATION_READ_COMMITTED
,TransactionDefinition.ISOLATION_REPEATABLE_READ
,TransactionDefinition.ISOLATION_SERIALIZABLE
,TransactionDefinition.getIsolationLevel()
setActualTransactionActive
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.- 参数:
active
-true
to mark the current thread as being associated with an actual transaction;false
to reset that marker
isActualTransactionActive
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 discriminate between active transaction synchronization (with or without backing resource transaction; also on PROPAGATION_SUPPORTS) and an actual transaction being active (with backing resource transaction; on PROPAGATION_REQUIRED, PROPAGATION_REQUIRES_NEW, etc).
clear
public static void clear()
Clear the entire transaction synchronization state for the current thread: registered synchronizations as well as the various transaction characteristics.