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java.lang.Objectorg.springframework.jdbc.datasource.DelegatingDataSource
org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy
public class TransactionAwareDataSourceProxy
Proxy for a target JDBC DataSource, adding awareness of
 Spring-managed transactions. Similar to a transactional JNDI DataSource
 as provided by a J2EE 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 J2EE/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. Therefore, the returned Connections cannot be cast
 to a native JDBC Connection type like OracleConnection or to a connection
 pool implementation type. Use a corresponding
 NativeJdbcExtractor
 to retrieve the native JDBC Connection.
DataSource.getConnection(), 
Connection.close(), 
DataSourceUtils.doGetConnection(javax.sql.DataSource), 
DataSourceUtils.applyTransactionTimeout(java.sql.Statement, javax.sql.DataSource), 
DataSourceUtils.doReleaseConnection(java.sql.Connection, javax.sql.DataSource)| Constructor Summary | |
|---|---|
| TransactionAwareDataSourceProxy()Create a new TransactionAwareDataSourceProxy. | |
| TransactionAwareDataSourceProxy(DataSource targetDataSource)Create a new TransactionAwareDataSourceProxy. | |
| Method Summary | |
|---|---|
|  Connection | getConnection()Delegates to DataSourceUtils for automatically participating in Spring-managed transactions. | 
| 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. | 
|  void | setReobtainTransactionalConnections(boolean reobtainTransactionalConnections)Specify whether to reobtain the target Connection for each operation performed within a transaction. | 
| 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. | 
| Methods inherited from class org.springframework.jdbc.datasource.DelegatingDataSource | 
|---|
| afterPropertiesSet, getConnection, getLoginTimeout, getLogWriter, getTargetDataSource, isWrapperFor, setLoginTimeout, setLogWriter, setTargetDataSource, unwrap | 
| Methods inherited from class java.lang.Object | 
|---|
| clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait | 
| Constructor Detail | 
|---|
public TransactionAwareDataSourceProxy()
DelegatingDataSource.setTargetDataSource(javax.sql.DataSource)public TransactionAwareDataSourceProxy(DataSource targetDataSource)
targetDataSource - the target DataSource| Method Detail | 
|---|
public void setReobtainTransactionalConnections(boolean reobtainTransactionalConnections)
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".
public Connection getConnection()
                         throws SQLException
The returned Connection handle implements the ConnectionProxy interface, allowing to retrieve the underlying target Connection.
getConnection in interface DataSourcegetConnection in class DelegatingDataSourceSQLExceptionDataSourceUtils.doGetConnection(javax.sql.DataSource), 
ConnectionProxy.getTargetConnection()protected Connection getTransactionAwareConnectionProxy(DataSource targetDataSource)
close() calls to DataSourceUtils.
targetDataSource - DataSource that the Connection came from
Connection.close(), 
DataSourceUtils.doReleaseConnection(java.sql.Connection, javax.sql.DataSource)protected boolean shouldObtainFixedConnection(DataSource targetDataSource)
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.
targetDataSource - the target DataSource| 
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