org.springframework.jdbc.datasource

Class DataSourceTransactionManager

  • All Implemented Interfaces:
    java.io.Serializable, InitializingBean, PlatformTransactionManager, ResourceTransactionManager


    public class DataSourceTransactionManager
    extends AbstractPlatformTransactionManager
    implements ResourceTransactionManager, InitializingBean
    PlatformTransactionManager implementation for a single JDBC DataSource. This class is capable of working in any environment with any JDBC driver, as long as the setup uses a javax.sql.DataSource as its Connection factory mechanism. Binds a JDBC Connection from the specified DataSource to the current thread, potentially allowing for one thread-bound Connection per DataSource.

    Note: The DataSource that this transaction manager operates on needs to return independent Connections. The Connections may come from a pool (the typical case), but the DataSource must not return thread-scoped / request-scoped Connections or the like. This transaction manager will associate Connections with thread-bound transactions itself, according to the specified propagation behavior. It assumes that a separate, independent Connection can be obtained even during an ongoing transaction.

    Application code is required to retrieve the JDBC Connection via DataSourceUtils.getConnection(DataSource) instead of a standard Java EE-style DataSource.getConnection() call. Spring classes such as JdbcTemplate use this strategy implicitly. If not used in combination with this transaction manager, the DataSourceUtils lookup strategy behaves exactly like the native DataSource lookup; it can thus be used in a portable fashion.

    Alternatively, you can allow application code to work with the standard Java EE-style lookup pattern DataSource.getConnection(), for example for legacy code that is not aware of Spring at all. In that case, define a TransactionAwareDataSourceProxy for your target DataSource, and pass that proxy DataSource to your DAOs, which will automatically participate in Spring-managed transactions when accessing it.

    Supports custom isolation levels, and timeouts which get applied as appropriate JDBC statement timeouts. To support the latter, application code must either use JdbcTemplate, call DataSourceUtils.applyTransactionTimeout(java.sql.Statement, javax.sql.DataSource) for each created JDBC Statement, or go through a TransactionAwareDataSourceProxy which will create timeout-aware JDBC Connections and Statements automatically.

    Consider defining a LazyConnectionDataSourceProxy for your target DataSource, pointing both this transaction manager and your DAOs to it. This will lead to optimized handling of "empty" transactions, i.e. of transactions without any JDBC statements executed. A LazyConnectionDataSourceProxy will not fetch an actual JDBC Connection from the target DataSource until a Statement gets executed, lazily applying the specified transaction settings to the target Connection.

    This transaction manager supports nested transactions via the JDBC 3.0 Savepoint mechanism. The "nestedTransactionAllowed" flag defaults to "true", since nested transactions will work without restrictions on JDBC drivers that support savepoints (such as the Oracle JDBC driver).

    This transaction manager can be used as a replacement for the JtaTransactionManager in the single resource case, as it does not require a container that supports JTA, typically in combination with a locally defined JDBC DataSource (e.g. an Apache Commons DBCP connection pool). Switching between this local strategy and a JTA environment is just a matter of configuration!

    As of 4.3.4, this transaction manager triggers flush callbacks on registered transaction synchronizations (if synchronization is generally active), assuming resources operating on the underlying JDBC Connection. This allows for setup analogous to JtaTransactionManager, in particular with respect to lazily registered ORM resources (e.g. a Hibernate Session).

    Since:
    02.05.2003
    Author:
    Juergen Hoeller
    See Also:
    AbstractPlatformTransactionManager.setNestedTransactionAllowed(boolean), Savepoint, DataSourceUtils.getConnection(javax.sql.DataSource), DataSourceUtils.applyTransactionTimeout(java.sql.Statement, javax.sql.DataSource), DataSourceUtils.releaseConnection(java.sql.Connection, javax.sql.DataSource), TransactionAwareDataSourceProxy, LazyConnectionDataSourceProxy, JdbcTemplate, Serialized Form
    • Constructor Detail

      • DataSourceTransactionManager

        public DataSourceTransactionManager()
        Create a new DataSourceTransactionManager instance. A DataSource has to be set to be able to use it.
        See Also:
        setDataSource(javax.sql.DataSource)
      • DataSourceTransactionManager

        public DataSourceTransactionManager(javax.sql.DataSource dataSource)
        Create a new DataSourceTransactionManager instance.
        Parameters:
        dataSource - the JDBC DataSource to manage transactions for
    • Method Detail

      • setDataSource

        public void setDataSource(@Nullable
                                  javax.sql.DataSource dataSource)
        Set the JDBC DataSource that this instance should manage transactions for.

        This will typically be a locally defined DataSource, for example an Apache Commons DBCP connection pool. Alternatively, you can also drive transactions for a non-XA J2EE DataSource fetched from JNDI. For an XA DataSource, use JtaTransactionManager.

        The DataSource specified here should be the target DataSource to manage transactions for, not a TransactionAwareDataSourceProxy. Only data access code may work with TransactionAwareDataSourceProxy, while the transaction manager needs to work on the underlying target DataSource. If there's nevertheless a TransactionAwareDataSourceProxy passed in, it will be unwrapped to extract its target DataSource.

        The DataSource passed in here needs to return independent Connections. The Connections may come from a pool (the typical case), but the DataSource must not return thread-scoped / request-scoped Connections or the like.

        See Also:
        TransactionAwareDataSourceProxy, JtaTransactionManager
      • getDataSource

        @Nullable
        public javax.sql.DataSource getDataSource()
        Return the JDBC DataSource that this instance manages transactions for.
      • obtainDataSource

        protected javax.sql.DataSource obtainDataSource()
        Obtain the DataSource for actual use.
        Returns:
        the DataSource (never null)
        Throws:
        java.lang.IllegalStateException - in case of no DataSource set
        Since:
        5.0
      • setEnforceReadOnly

        public void setEnforceReadOnly(boolean enforceReadOnly)
        Specify whether to enforce the read-only nature of a transaction (as indicated by TransactionDefinition.isReadOnly() through an explicit statement on the transactional connection: "SET TRANSACTION READ ONLY" as understood by Oracle, MySQL and Postgres.

        The exact treatment, including any SQL statement executed on the connection, can be customized through through prepareTransactionalConnection(java.sql.Connection, org.springframework.transaction.TransactionDefinition).

        This mode of read-only handling goes beyond the Connection.setReadOnly(boolean) hint that Spring applies by default. In contrast to that standard JDBC hint, "SET TRANSACTION READ ONLY" enforces an isolation-level-like connection mode where data manipulation statements are strictly disallowed. Also, on Oracle, this read-only mode provides read consistency for the entire transaction.

        Note that older Oracle JDBC drivers (9i, 10g) used to enforce this read-only mode even for Connection.setReadOnly(true. However, with recent drivers, this strong enforcement needs to be applied explicitly, e.g. through this flag.

        Since:
        4.3.7
        See Also:
        prepareTransactionalConnection(java.sql.Connection, org.springframework.transaction.TransactionDefinition)
      • isEnforceReadOnly

        public boolean isEnforceReadOnly()
        Return whether to enforce the read-only nature of a transaction through an explicit statement on the transactional connection.
        Since:
        4.3.7
        See Also:
        setEnforceReadOnly(boolean)
      • afterPropertiesSet

        public void afterPropertiesSet()
        Description copied from interface: InitializingBean
        Invoked by the containing BeanFactory after it has set all bean properties and satisfied BeanFactoryAware, ApplicationContextAware etc.

        This method allows the bean instance to perform validation of its overall configuration and final initialization when all bean properties have been set.

        Specified by:
        afterPropertiesSet in interface InitializingBean
      • isExistingTransaction

        protected boolean isExistingTransaction(java.lang.Object transaction)
        Description copied from class: AbstractPlatformTransactionManager
        Check if the given transaction object indicates an existing transaction (that is, a transaction which has already started).

        The result will be evaluated according to the specified propagation behavior for the new transaction. An existing transaction might get suspended (in case of PROPAGATION_REQUIRES_NEW), or the new transaction might participate in the existing one (in case of PROPAGATION_REQUIRED).

        The default implementation returns false, assuming that participating in existing transactions is generally not supported. Subclasses are of course encouraged to provide such support.

        Overrides:
        isExistingTransaction in class AbstractPlatformTransactionManager
        Parameters:
        transaction - transaction object returned by doGetTransaction
        Returns:
        if there is an existing transaction
        See Also:
        AbstractPlatformTransactionManager.doGetTransaction()
      • doBegin

        protected void doBegin(java.lang.Object transaction,
                               TransactionDefinition definition)
        This implementation sets the isolation level but ignores the timeout.
        Specified by:
        doBegin in class AbstractPlatformTransactionManager
        Parameters:
        transaction - transaction object returned by doGetTransaction
        definition - a TransactionDefinition instance, describing propagation behavior, isolation level, read-only flag, timeout, and transaction name
      • doSetRollbackOnly

        protected void doSetRollbackOnly(DefaultTransactionStatus status)
        Description copied from class: AbstractPlatformTransactionManager
        Set the given transaction rollback-only. Only called on rollback if the current transaction participates in an existing one.

        The default implementation throws an IllegalTransactionStateException, assuming that participating in existing transactions is generally not supported. Subclasses are of course encouraged to provide such support.

        Overrides:
        doSetRollbackOnly in class AbstractPlatformTransactionManager
        Parameters:
        status - the status representation of the transaction
      • doCleanupAfterCompletion

        protected void doCleanupAfterCompletion(java.lang.Object transaction)
        Description copied from class: AbstractPlatformTransactionManager
        Cleanup resources after transaction completion.

        Called after doCommit and doRollback execution, on any outcome. The default implementation does nothing.

        Should not throw any exceptions but just issue warnings on errors.

        Overrides:
        doCleanupAfterCompletion in class AbstractPlatformTransactionManager
        Parameters:
        transaction - transaction object returned by doGetTransaction
      • prepareTransactionalConnection

        protected void prepareTransactionalConnection(java.sql.Connection con,
                                                      TransactionDefinition definition)
                                               throws java.sql.SQLException
        Prepare the transactional Connection right after transaction begin.

        The default implementation executes a "SET TRANSACTION READ ONLY" statement if the "enforceReadOnly" flag is set to true and the transaction definition indicates a read-only transaction.

        The "SET TRANSACTION READ ONLY" is understood by Oracle, MySQL and Postgres and may work with other databases as well. If you'd like to adapt this treatment, override this method accordingly.

        Parameters:
        con - the transactional JDBC Connection
        definition - the current transaction definition
        Throws:
        java.sql.SQLException - if thrown by JDBC API
        Since:
        4.3.7
        See Also:
        setEnforceReadOnly(boolean)