Proxy for a target JDBC javax.sql.DataSource, adding awareness of Spring-managed transactions. Similar to a transactional JNDI DataSource as provided by a Jakarta EE server.

Data access code that should remain unaware of Spring's data access support can work with this proxy to seamlessly participate in Spring-managed transactions. Note that the transaction manager, for example DataSourceTransactionManager, still needs to work with the underlying DataSource, not with this proxy.

Make sure that TransactionAwareDataSourceProxy is the outermost DataSource of a chain of DataSource proxies/adapters. TransactionAwareDataSourceProxy can delegate either directly to the target connection pool or to some intermediary proxy/adapter like LazyConnectionDataSourceProxy or UserCredentialsDataSourceAdapter.

Delegates to DataSourceUtils for automatically participating in thread-bound transactions, for example managed by DataSourceTransactionManager. getConnection calls and close calls on returned Connections will behave properly within a transaction, i.e. always operate on the transactional Connection. If not within a transaction, normal DataSource behavior applies.

This proxy allows data access code to work with the plain JDBC API and still participate in Spring-managed transactions, similar to JDBC code in a Jakarta EE/JTA environment. However, if possible, use Spring's DataSourceUtils, JdbcTemplate or JDBC operation objects to get transaction participation even without a proxy for the target DataSource, avoiding the need to define such a proxy in the first place.

As a further effect, using a transaction-aware DataSource will apply remaining transaction timeouts to all created JDBC (Prepared/Callable)Statement. This means that all operations performed through standard JDBC will automatically participate in Spring-managed transaction timeouts.

Note

This DataSource proxy needs to return wrapped Connections (which implement the ConnectionProxy interface) in order to handle close calls properly. Use Connection#unwrap to retrieve the native JDBC Connection.

Nested and Inner Type Summary

Modifier and Type	Class and Description
private class	TransactionAwareDataSourceProxy.TransactionAwareInvocationHandler Invocation handler that delegates close calls on JDBC Connections to DataSourceUtils for being aware of thread-bound transactions.

Field Summary

Modifier and Type	Field and Description
private boolean	lazyTransactionalConnections
private boolean	reobtainTransactionalConnections

Access	Constructor and Description
public	TransactionAwareDataSourceProxy() Create a new TransactionAwareDataSourceProxy.
public	TransactionAwareDataSourceProxy(DataSource the target DataSource targetDataSource) Create a new TransactionAwareDataSourceProxy.

Method Summary

Modifier and Type	Method and Description
public Connection	Returns: a transactional Connection if any, a new one else getConnection() Overrides org.springframework.jdbc.datasource.DelegatingDataSource.getConnection. Implements javax.sql.DataSource.getConnection. Delegates to DataSourceUtils for automatically participating in Spring-managed transactions.
protected Connection	Returns: the wrapped Connection getTransactionAwareConnectionProxy(DataSource the DataSource that the Connection came from targetDataSource) Wraps the given Connection with a proxy that delegates every method call to it but delegates `close()` calls to DataSourceUtils.
public void	setLazyTransactionalConnections(boolean lazyTransactionalConnections) Specify whether to obtain the transactional target Connection lazily on actual data access.
public void	setReobtainTransactionalConnections(boolean reobtainTransactionalConnections) Specify whether to reobtain the target Connection for each operation performed within a transaction.
protected boolean	shouldObtainFixedConnection(DataSource the target DataSource targetDataSource) Determine whether to obtain a fixed target Connection for the proxy or to reobtain the target Connection for each operation.

Inherited from org.springframework.jdbc.datasource.DelegatingDataSource:: afterPropertiesSet createConnectionBuilder createShardingKeyBuilder getConnection getLoginTimeout getLogWriter getParentLogger getTargetDataSource isWrapperFor obtainTargetDataSource setLoginTimeout setLogWriter setTargetDataSource unwrap

Field Detail

lazyTransactionalConnections	back to summary
private boolean lazyTransactionalConnections

reobtainTransactionalConnections	back to summary
private boolean reobtainTransactionalConnections

TransactionAwareDataSourceProxy	back to summary
public TransactionAwareDataSourceProxy() Create a new TransactionAwareDataSourceProxy. See Also `setTargetDataSource`

TransactionAwareDataSourceProxy	back to summary
public TransactionAwareDataSourceProxy(DataSource targetDataSource) Create a new TransactionAwareDataSourceProxy. Parameters targetDataSource:DataSource the target DataSource

Method Detail

getConnection back to summary

getConnection	back to summary
public Connection getConnection() throws SQLException Overrides org.springframework.jdbc.datasource.DelegatingDataSource.getConnection. Implements javax.sql.DataSource.getConnection. Delegates to DataSourceUtils for automatically participating in Spring-managed transactions. Throws the original SQLException, if any. The returned Connection handle implements the ConnectionProxy interface, allowing to retrieve the underlying target Connection. Returns:Connection a transactional Connection if any, a new one else Annotations @Override Exceptions SQLException: Doc from javax.sql.DataSource.getConnection. if a database access error occurs See Also `DataSourceUtils#doGetConnection`, `ConnectionProxy#getTargetConnection`

public Connection getConnection() throws SQLException

Overrides org.springframework.jdbc.datasource.DelegatingDataSource.getConnection.

Implements javax.sql.DataSource.getConnection.

Delegates to DataSourceUtils for automatically participating in Spring-managed transactions. Throws the original SQLException, if any.

The returned Connection handle implements the ConnectionProxy interface, allowing to retrieve the underlying target Connection.

Returns:Connection

a transactional Connection if any, a new one else

Annotations

@Override

Exceptions

SQLException:

Doc from javax.sql.DataSource.getConnection.

if a database access error occurs

getTransactionAwareConnectionProxy back to summary

getTransactionAwareConnectionProxy	back to summary
protected Connection getTransactionAwareConnectionProxy(DataSource targetDataSource) Wraps the given Connection with a proxy that delegates every method call to it but delegates `close()` calls to DataSourceUtils. Parameters targetDataSource:DataSource the DataSource that the Connection came from Returns:Connection the wrapped Connection See Also `java.sql.Connection#close()`, `DataSourceUtils#doReleaseConnection`

protected Connection getTransactionAwareConnectionProxy(DataSource targetDataSource)

Wraps the given Connection with a proxy that delegates every method call to it but delegates close() calls to DataSourceUtils.

Parameters

targetDataSource:DataSource: the DataSource that the Connection came from

Returns:Connection

the wrapped Connection

setLazyTransactionalConnections	back to summary
public void setLazyTransactionalConnections(boolean lazyTransactionalConnections) Specify whether to obtain the transactional target Connection lazily on actual data access. The default is "true". Specify "false" to immediately obtain a target Connection when a transaction-aware Connection handle is retrieved. Since 6.1.2

setLazyTransactionalConnections

back to summary

public void setLazyTransactionalConnections(boolean lazyTransactionalConnections)

Specify whether to obtain the transactional target Connection lazily on actual data access.

The default is "true". Specify "false" to immediately obtain a target Connection when a transaction-aware Connection handle is retrieved.

Since: 6.1.2

setReobtainTransactionalConnections	back to summary
public void setReobtainTransactionalConnections(boolean reobtainTransactionalConnections) Specify whether to reobtain the target Connection for each operation performed within a transaction. The default is "false". Specify "true" to reobtain transactional Connections for every call on the Connection proxy; this is advisable on JBoss if you hold on to a Connection handle across transaction boundaries. The effect of this setting is similar to the "hibernate.connection.release_mode" value "after_statement".

setReobtainTransactionalConnections

back to summary

public void setReobtainTransactionalConnections(boolean reobtainTransactionalConnections)

Specify whether to reobtain the target Connection for each operation performed within a transaction.

The default is "false". Specify "true" to reobtain transactional Connections for every call on the Connection proxy; this is advisable on JBoss if you hold on to a Connection handle across transaction boundaries.

The effect of this setting is similar to the "hibernate.connection.release_mode" value "after_statement".

shouldObtainFixedConnection back to summary

shouldObtainFixedConnection	back to summary
protected boolean shouldObtainFixedConnection(DataSource targetDataSource) Determine whether to obtain a fixed target Connection for the proxy or to reobtain the target Connection for each operation. The default implementation returns `true` for all standard cases. This can be overridden through the `"reobtainTransactionalConnections"` flag, which enforces a non-fixed target Connection within an active transaction. Note that non-transactional access will always use a fixed Connection. Parameters targetDataSource:DataSource the target DataSource

protected boolean shouldObtainFixedConnection(DataSource targetDataSource)

Determine whether to obtain a fixed target Connection for the proxy or to reobtain the target Connection for each operation.

The default implementation returns true for all standard cases. This can be overridden through the "reobtainTransactionalConnections" flag, which enforces a non-fixed target Connection within an active transaction. Note that non-transactional access will always use a fixed Connection.

Parameters

targetDataSource:DataSource: the target DataSource

org.springframework.jdbc.datasource back to summary

private Class TransactionAwareDataSourceProxy.TransactionAwareInvocationHandler

Class Inheritance

extends Object
implements InvocationHandler

java.lang.Object
org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy.TransactionAwareInvocationHandler

All Implemented Interfaces

java.lang.reflect.InvocationHandler

Invocation handler that delegates close calls on JDBC Connections to DataSourceUtils for being aware of thread-bound transactions.

Field Summary

Modifier and Type	Field and Description
private boolean	closed
private Connection	target
private final DataSource	targetDataSource

Constructor Summary

Access	Constructor and Description
public	TransactionAwareInvocationHandler(DataSource targetDataSource)

Method Summary

Modifier and Type Method and Description

Modifier and Type	Method and Description
public Object	invoke(Object the proxy instance that the method was invoked on proxy, Method the `Method` instance corresponding to the interface method invoked on the proxy instance. The declaring class of the `Method` object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through. method, Object[] an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or `null` if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as `java.lang.Integer` or `java.lang.Boolean`. args) Implements java.lang.reflect.InvocationHandler.invoke. Processes a method invocation on a proxy instance and returns the result.

public Object

invoke(Object

the proxy instance that the method was invoked on

proxy, Method

the Method instance corresponding to the interface method invoked on the proxy instance. The declaring class of the Method object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through.

method, Object[]

an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as java.lang.Integer or java.lang.Boolean.

args)

Implements java.lang.reflect.InvocationHandler.invoke.

Processes a method invocation on a proxy instance and returns the result.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

closed	back to summary
private boolean closed

target	back to summary
private Connection target Annotations @Nullable

targetDataSource	back to summary
private final DataSource targetDataSource

Constructor Detail

TransactionAwareInvocationHandler	back to summary
public TransactionAwareInvocationHandler(DataSource targetDataSource)

Method Detail

invoke back to summary

invoke	back to summary
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable Implements java.lang.reflect.InvocationHandler.invoke. Doc from java.lang.reflect.InvocationHandler.invoke. Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with. Parameters proxy:Object the proxy instance that the method was invoked on method:Method the `Method` instance corresponding to the interface method invoked on the proxy instance. The declaring class of the `Method` object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through. args:Object[] an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or `null` if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as `java.lang.Integer` or `java.lang.Boolean`. Returns:Object the value to return from the method invocation on the proxy instance. If the declared return type of the interface method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is `null` and the interface method's return type is primitive, then a `NullPointerException` will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, a `ClassCastException` will be thrown by the method invocation on the proxy instance. Annotations @Override @Nullable Exceptions Throwable: the exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the `throws` clause of the interface method or to the unchecked exception types `java.lang.RuntimeException` or `java.lang.Error`. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the `throws` clause of the interface method, then an `UndeclaredThrowableException` containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.

public Object invoke(Object proxy, Method method, Object[] args) throws Throwable

Implements java.lang.reflect.InvocationHandler.invoke.

Doc from java.lang.reflect.InvocationHandler.invoke.

Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with.

Parameters

proxy:Object: the proxy instance that the method was invoked on
method:Method: the Method instance corresponding to the interface method invoked on the proxy instance. The declaring class of the Method object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through.
args:Object[]: an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as java.lang.Integer or java.lang.Boolean.

Returns:Object

the value to return from the method invocation on the proxy instance. If the declared return type of the interface method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is null and the interface method's return type is primitive, then a NullPointerException will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, a ClassCastException will be thrown by the method invocation on the proxy instance.

Annotations

@Override
@Nullable

Exceptions

Throwable:: the exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the throws clause of the interface method or to the unchecked exception types java.lang.RuntimeException or java.lang.Error. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the throws clause of the interface method, then an UndeclaredThrowableException containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.

public Class TransactionAwareDataSourceProxy

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private Class TransactionAwareDataSourceProxy.TransactionAwareInvocationHandler

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail