Hibernate transaction and 'for update' - mysql

Question

I'm trying to obtain the lock on some rows on my mysql database using the "for update" statement. To do that I create a Criteria in the middle of an Hibernate Transaction and set a lock on it.
crit = session.createCriteria(AppIosVersion.class)
.add(Restrictions.eq("version", version))
.setLockMode(LockMode.PESSIMISTIC_WRITE);
Using setLockMode the query is correctly sent to the database, this is what I see in mysql.log:
133 Query SET autocommit=0
133 Query SET autocommit=1
133 Query SET autocommit=0
133 Query select this_.Version as Version1_5_0_, this_.EditTimeStamp as EditTime2_5_0_, this_.IsActive as IsActive3_5_0_ from AppAndroidVersion this_ where this_.Version='0.2' for update
130703 16:46:03 133 Query rollback
133 Query SET autocommit=1
The problem is that the for update statement doesn't allow to acquire the lock because hibernate beginTransaction() doesn't become START TRANSACTION in mysql.
My hibernate configuration is the following (i'm not using Spring).
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/Versions?autoReconnect=true</property>
<property name="connection.username">name</property>
<property name="connection.password">password</property>
<!-- Session properties -->
<!-- <property name="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property> -->
<property name="hibernate.current_session_context_class">org.hibernate.context.internal.ThreadLocalSessionContext</property>
<property name="hibernate.connection.autocommit">false</property>
<!-- configuration pool via c3p0-->
<property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
<property name="hibernate.c3p0.max_size">100</property>
<property name="hibernate.c3p0.min_size">10</property>
<property name="hibernate.c3p0.acquire_increment">2</property>
<property name="hibernate.c3p0.idle_test_period">180</property>
<property name="hibernate.c3p0.max_statements">0</property>
<property name="hibernate.c3p0.timeout">600</property>
<property name="hibernate.c3p0.debugUnreturnedConnectionStackTraces">true</property>
<property name="hibernate.c3p0.unreturnedConnectionTimeout">180</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>

Answer 1

If you don't use declarative transaction management provided by container like Spring, you have to explicitly deal with the transaction.
One simple way is to implement a TransactionTemplate like Spring does.
BTW, be careful to use statement like 'select xxx for update', make sure you release the lock properly and no other transaction will touch the locked rows.