Java Doc for JpaTransactionManager.java in  » J2EE » spring-framework-2.0.6 » org » springframework » orm » jpa » Java Source Code / Java DocumentationJava Source Code and Java Documentation

This transaction manager is appropriate for applications that use a single JPA EntityManagerFactory for transactional data access. JTA (usually through org.springframework.transaction.jta.JtaTransactionManager ) is necessary for accessing multiple transactional resources within the same transaction. Note that you need to configure your JPA provider accordingly in order to make it participate in JTA transactions.

This transaction manager also supports direct DataSource access within a transaction (i.e. plain JDBC code working with the same DataSource). This allows for mixing services which access JPA and services which use plain JDBC (without being aware of JPA)! Application code needs to stick to the same simple Connection lookup pattern as with org.springframework.jdbc.datasource.DataSourceTransactionManager (i.e. org.springframework.jdbc.datasource.DataSourceUtils.getConnection or going through a org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy ). Note that this requires a vendor-specific JpaDialect to be configured.

Note: To be able to register a DataSource's Connection for plain JDBC code, this instance needs to be aware of the DataSource ( JpaTransactionManager.setDataSource ). The given DataSource should obviously match the one used by the given EntityManagerFactory. This transaction manager will autodetect the DataSource used as known connection factory of the EntityManagerFactory, so you usually don't need to explicitly specify the "dataSource" property.

On JDBC 3.0, this transaction manager supports nested transactions via JDBC 3.0 Savepoints. The JpaTransactionManager.setNestedTransactionAllowed "nestedTransactionAllowed"} flag defaults to "false", though, as nested transactions will just apply to the JDBC Connection, not to the JPA EntityManager and its cached objects. You can manually set the flag to "true" if you want to use nested transactions for JDBC access code which participates in JPA transactions (provided that your JDBC driver supports Savepoints). Note that JPA itself does not support nested transactions! Hence, do not expect JPA access code to semantically participate in a nested transaction.
author:
   Juergen Hoeller
since:
   2.0
See Also:   JpaTransactionManager.setEntityManagerFactory
See Also:   JpaTransactionManager.setDataSource
See Also:   LocalEntityManagerFactoryBean
See Also:   JpaTemplate.execute
See Also:   org.springframework.orm.jpa.support.SharedEntityManagerBean
See Also:   org.springframework.jdbc.datasource.DataSourceUtils.getConnection
See Also:   org.springframework.jdbc.datasource.DataSourceUtils.releaseConnection
See Also:   org.springframework.jdbc.core.JdbcTemplate
See Also:   org.springframework.jdbc.datasource.DataSourceTransactionManager
See Also:   org.springframework.transaction.jta.JtaTransactionManager

If the EntityManagerFactory uses a known DataSource as connection factory, the DataSource will be autodetected: You can still explictly specify the DataSource, but you don't need to in this case.

A transactional JDBC Connection for this DataSource will be provided to application code accessing this DataSource directly via DataSourceUtils or JdbcTemplate.

The default implementation checks whether the EntityManagerFactory is a Spring proxy and unwraps it first.
See Also:   javax.persistence.EntityManagerFactory.createEntityManager
See Also:   EntityManagerFactoryInfo.getNativeEntityManagerFactory

Useful for specifying entries directly, for example via "jpaPropertyMap[myKey]".

If the EntityManagerFactory uses a known DataSource as connection factory, the DataSource will be autodetected: You can still explictly specify the DataSource, but you don't need to in this case.

A transactional JDBC Connection for this DataSource will be provided to application code accessing this DataSource directly via DataSourceUtils or JdbcTemplate. The Connection will be taken from the JPA EntityManager.

Note that you need to use a JPA dialect for a specific JPA implementation to allow for exposing JPA transactions as JDBC transactions.

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.
See Also:   EntityManagerFactoryInfo.getDataSource
See Also:   JpaTransactionManager.setJpaDialect
See Also:   org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy
See Also:   org.springframework.jdbc.datasource.DataSourceUtils
See Also:   org.springframework.jdbc.core.JdbcTemplate

If the EntityManagerFactory uses a known JpaDialect, it will be autodetected: You can still explictly specify the DataSource, but you don't need to in this case.

The dialect object can be used to retrieve the underlying JDBC connection and thus allows for exposing JPA transactions as JDBC transactions.
See Also:   EntityManagerFactoryInfo.getJpaDialect
See Also:   JpaDialect.beginTransaction
See Also:   JpaDialect.getJdbcConnection

Can be populated with a String "value" (parsed via PropertiesEditor) or a "props" element in XML bean definitions.
See Also:   javax.persistence.EntityManagerFactory.createEntityManager(java.util.Map)

Can be populated with a "map" or "props" element in XML bean definitions.
See Also:   javax.persistence.EntityManagerFactory.createEntityManager(java.util.Map)