Spring Transaction

Topics

● Transaction types
● Isolation levels
● Propagation
● Transaction support in Spring
● Declarative transaction


Transaction Types

● Local transaction
      – Specific to a single transactional resource (example: JDBC)
● Global transaction
      – Managed by container

      – Can span multiple transactional resources

Transaction Isolation Levels

● You can specify per method

Transaction Isolation Levels

● ISOLATION_DEFAULT
● ISOLATION_READ_UNCOMMITTED
         – Dirty reads, non-repeatable reads and phantom reads can occur.
● ISOLATION_READ_COMMITTED
        – Dirty reads are prevented; non-repeatable reads and phantom reads can occur.
● ISOLATION_REPEATABLE_READ
        – Dirty reads and non-repeatable reads are prevented; phantom reads can occur.
● ISOLATION_SERIALIZABLE
        – Dirty reads, non-repeatable reads and phantom reads are prevented

Transaction Propagation


● PROPAGATION_REQUIRED
       – Support a current transaction, create a new one if none exists.
● PROPAGATION_SUPPORTS
       – Support a current transaction, execute non-transactionally if none exists.
● PROPAGATION_MANDATORY
       – Support a current transaction, throw an exception if none exists.
● PROPAGATION_REQUIRES_NEW
       – Create a new transaction, suspend the current transaction if one
exists.
● PROPAGATION_NOT_SUPPORTED
● PROPAGATION_NEVER
● PROPAGATION_NESTED


Transaction Support in Spring

● Declarative transaction
● Programmatic transaction

Declarative Transaction

● You can declaratively specify that a method on a bean has transactional properties
         – Spring handles the transactional behavior
● Built upon AOP
         – For intercepting calls to methods for performing transaction
● No need to modify the code
        – The code does not contain any transaction management code
        – Changing transactional properties is just changing the configuration file
● A group of methods can be specified with a same transactional properties
        – wildcard

● Additional interceptors can be plugged in

Configuration of Declarative Transaction

<bean id="clinicTarget" class="org.springframework.samples.petclinic.hibernate.HibernateClinic">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
<bean id="clinic"
class="org.springframework.transaction.interceptor.TransactionProxyFact
oryBean">
<property name="transactionManager" ref="transactionManager"/>
<property name="target" ref="clinicTarget"/>
<property name="transactionAttributes">
<props>
<prop key="get*">PROPAGATION_REQUIRED,readOnly</prop>
<prop key="find*">PROPAGATION_REQUIRED,readOnly</prop>
<prop key="load*">PROPAGATION_REQUIRED,readOnly</prop>
<prop key="store*">PROPAGATION_REQUIRED</prop>
</props>
</property>

</bean>
<!-- Transaction manager for a single Hibernate SessionFactory
(alternative to JTA) -->
<bean id="transactionManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory"/>
</bean>
<!-- Transaction manager that delegates to JTA (for a transactional JNDI
DataSource) -->
<!--
<bean id="transactionManager"
class="org.springframework.transaction.jta.JtaTransactionManager"/>

-->

Business Logic Class

public class HibernateClinic extends HibernateDaoSupport implements Clinic {

public Collection getVets() throws DataAccessException {
return getHibernateTemplate().find("from Vet vet order by vet.lastName,
vet.firstName");
}
public Collection getPetTypes() throws DataAccessException {
return getHibernateTemplate().find("from PetType type order by type.name");
}
public Collection findOwners(String lastName) throws DataAccessException {
return getHibernateTemplate().find("from Owner owner where owner.lastName
like ?", lastName + "%");

}



Thank You!