HibernateJpaDialect (Spring Framework 3.2.1.RELEASE API)
Date: 2013-01-24

org.springframework.orm.jpa.vendor

## Class HibernateJpaDialect

- java.lang.Object
- - org.springframework.orm.jpa.DefaultJpaDialect
  - - org.springframework.orm.jpa.vendor.HibernateJpaDialect

- All Implemented Interfaces:
    Serializable, PersistenceExceptionTranslator, JpaDialect

      public class HibernateJpaDialect
      extends DefaultJpaDialect

  `JpaDialect` implementation for Hibernate EntityManager. Developed against Hibernate 3.3; tested against 3.3, 3.5, 3.6 and 4.0 (with the latter including Hibernate EntityManager in the Hibernate core distribution).
  Since:
    2.0
  Author:
    Costin Leau, Juergen Hoeller
  See Also:
    Serialized Form

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `HibernateJpaDialect()`

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `Object` | `beginTransaction(EntityManager entityManager, TransactionDefinition definition)` This implementation invokes the standard JPA `Transaction.begin` method.
    `void` | `cleanupTransaction(Object transactionData)` This implementation does nothing, since the default `beginTransaction` implementation does not require any cleanup.
    `ConnectionHandle` | `getJdbcConnection(EntityManager entityManager, boolean readOnly)` This implementation always returns `null`, indicating that no JDBC Connection can be provided.
    `protected Session` | `getSession(EntityManager em)`
    `Object` | `prepareTransaction(EntityManager entityManager, boolean readOnly, String name)` Prepare a JPA transaction, applying the specified semantics.
    `DataAccessException` | `translateExceptionIfPossible(RuntimeException ex)` This implementation delegates to EntityManagerFactoryUtils.

    - ### Methods inherited from class org.springframework.orm.jpa.DefaultJpaDialect

      `getEntityManagerFactoryPlusOperations, getEntityManagerPlusOperations, releaseJdbcConnection, supportsEntityManagerFactoryPlusOperations, supportsEntityManagerPlusOperations`

    - ### Methods inherited from class java.lang.Object

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

- - ### Constructor Detail

    - #### HibernateJpaDialect

          public HibernateJpaDialect()

  - ### Method Detail

    - #### beginTransaction

          public Object beginTransaction(EntityManager entityManager,
                                TransactionDefinition definition)
                                  throws PersistenceException,
                                         SQLException,
                                         TransactionException

      Description copied from class: `DefaultJpaDialect`
      This implementation invokes the standard JPA `Transaction.begin` method. Throws an InvalidIsolationLevelException if a non-default isolation level is set.

      This implementation does not return any transaction data Object, since there is no state to be kept for a standard JPA transaction. Hence, subclasses do not have to care about the return value (`null`) of this implementation and are free to return their own transaction data Object.

      Specified by:
        `beginTransaction` in interface `JpaDialect`
      Overrides:
        `beginTransaction` in class `DefaultJpaDialect`
      Parameters:
        `entityManager` - the EntityManager to begin a JPA transaction on
        `definition` - the Spring transaction definition that defines semantics
      Returns:
        an arbitrary object that holds transaction data, if any (to be passed into `JpaDialect.cleanupTransaction(java.lang.Object)`). May implement the `SavepointManager` interface.
      Throws:
        `PersistenceException` - if thrown by JPA methods
        `SQLException` - if thrown by JDBC methods
        `TransactionException` - in case of invalid arguments
      See Also:
        `EntityTransaction.begin()`, `InvalidIsolationLevelException`, `DefaultJpaDialect.cleanupTransaction(java.lang.Object)`

    - #### prepareTransaction

          public Object prepareTransaction(EntityManager entityManager,
                                  boolean readOnly,
                                  String name)
                                    throws PersistenceException

      Description copied from interface: `JpaDialect`
      Prepare a JPA transaction, applying the specified semantics. Called by EntityManagerFactoryUtils when enlisting an EntityManager in a JTA transaction.

      An implementation can apply the read-only flag as flush mode. In that case, a transaction data object can be returned that holds the previous flush mode (and possibly other data), to be reset in `cleanupTransaction`.

      Implementations can also use the Spring transaction name, as exposed by the passed-in TransactionDefinition, to optimize for specific data access use cases (effectively using the current transaction name as use case identifier).

      Specified by:
        `prepareTransaction` in interface `JpaDialect`
      Overrides:
        `prepareTransaction` in class `DefaultJpaDialect`
      Parameters:
        `entityManager` - the EntityManager to begin a JPA transaction on
        `readOnly` - whether the transaction is supposed to be read-only
        `name` - the name of the transaction (if any)
      Returns:
        an arbitrary object that holds transaction data, if any (to be passed into cleanupTransaction)
      Throws:
        `PersistenceException` - if thrown by JPA methods
      See Also:
        `JpaDialect.cleanupTransaction(java.lang.Object)`

    - #### cleanupTransaction

          public void cleanupTransaction(Object transactionData)

      Description copied from class: `DefaultJpaDialect`
      This implementation does nothing, since the default `beginTransaction` implementation does not require any cleanup.
      Specified by:
        `cleanupTransaction` in interface `JpaDialect`
      Overrides:
        `cleanupTransaction` in class `DefaultJpaDialect`
      Parameters:
        `transactionData` - arbitrary object that holds transaction data, if any (as returned by beginTransaction or prepareTransaction)
      See Also:
        `DefaultJpaDialect.beginTransaction(javax.persistence.EntityManager, org.springframework.transaction.TransactionDefinition)`

    - #### getJdbcConnection

          public ConnectionHandle getJdbcConnection(EntityManager entityManager,
                                           boolean readOnly)
                                             throws PersistenceException,
                                                    SQLException

      Description copied from class: `DefaultJpaDialect`
      This implementation always returns `null`, indicating that no JDBC Connection can be provided.
      Specified by:
        `getJdbcConnection` in interface `JpaDialect`
      Overrides:
        `getJdbcConnection` in class `DefaultJpaDialect`
      Parameters:
        `entityManager` - the current JPA EntityManager
        `readOnly` - whether the Connection is only needed for read-only purposes
      Returns:
        a handle for the JDBC Connection, to be passed into `releaseJdbcConnection`, or `null` if no JDBC Connection can be retrieved
      Throws:
        `PersistenceException` - if thrown by JPA methods
        `SQLException` - if thrown by JDBC methods
      See Also:
        `JpaDialect.releaseJdbcConnection(org.springframework.jdbc.datasource.ConnectionHandle, javax.persistence.EntityManager)`, `ConnectionHandle.getConnection()`, `SimpleConnectionHandle`, `JpaTransactionManager.setDataSource(javax.sql.DataSource)`, `NativeJdbcExtractor`

    - #### translateExceptionIfPossible

          public DataAccessException translateExceptionIfPossible(RuntimeException ex)

      Description copied from class: `DefaultJpaDialect`
      This implementation delegates to EntityManagerFactoryUtils.
      Specified by:
        `translateExceptionIfPossible` in interface `PersistenceExceptionTranslator`
      Overrides:
        `translateExceptionIfPossible` in class `DefaultJpaDialect`
      Parameters:
        `ex` - a RuntimeException thrown
      Returns:
        the corresponding DataAccessException (or `null` if the exception could not be translated, as in this case it may result from user code rather than an actual persistence problem)
      See Also:
        `EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(java.lang.RuntimeException)`

    - #### getSession

          protected Session getSession(EntityManager em)