Question

Still no luck with C3P0 pooling in Hibernate using Spring WebFlow if I use the following database.xml file and run my project I check the database and I only see two connects to it but I have it set to ten.

database.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"

    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                            http://www.springframework.org/schema/beans/spring-beans.xsd
                            http://www.springframework.org/schema/context 
                            http://www.springframework.org/schema/context/spring-context-3.0.xsd
                            http://www.springframework.org/schema/tx
                            http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
                            http://www.springframework.org/schema/jdbc
                            http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd">

    <context:property-placeholder location="classpath:jdbc.properties" />
    <context:component-scan base-package="org.uftwf" />
    <tx:annotation-driven transaction-manager="hibernateTransactionManager" />

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
        destroy-method="close">
        <property name="driverClass" value="${database.driver}" />
        <property name="jdbcUrl" value="${database.url}" />
        <property name="user" value="${database.user}" />
        <property name="password" value="${database.password}" />
    </bean>

    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="annotatedClasses">
            <list>
                <value>org.uftwf.schoolvisit.model.VisitModel</value>
                <value>org.uftwf.schoolvisit.model.NameID_lookupModel</value>
                <value>org.uftwf.schoolvisit.model.School_lookupModel</value>
            </list>
        </property>

        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${hibernate.dialect}</prop>
                <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
                <prop key="hibernate.use_sql_comments">${hibernate.use_sql_comments}</prop>
                <prop key="format_sql">${format_sql}</prop>
                <prop key="hibernate.c3p0.min_size">10</prop>
                <prop key="hibernate.c3p0.max_size">25</prop>
                <prop key="hibernate.c3p0.timeout">600</prop>
                <prop key="hibernate.c3p0.max_statements">0</prop>
                <prop key="hibernate.c3p0.idle_test_period">300</prop>
                <prop key="hibernate.c3p0.acquire_increment">5</prop>
            </props>
        </property>
    </bean>

    <bean id="hibernateTransactionManager"
        class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>
</beans>

But if I use this database.xml file I will see ten connects to the database but I want hibernate to manager the pool so can someone please tell me why the above database.xml does not work but the one below does?

database.xml:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"

    xsi:schemaLocation="http://www.springframework.org/schema/beans 
                            http://www.springframework.org/schema/beans/spring-beans.xsd
                            http://www.springframework.org/schema/context 
                            http://www.springframework.org/schema/context/spring-context-3.0.xsd
                            http://www.springframework.org/schema/tx
                            http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
                            http://www.springframework.org/schema/jdbc
                            http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd">

    <context:property-placeholder location="classpath:jdbc.properties" />
    <context:component-scan base-package="org.uftwf" />
    <tx:annotation-driven transaction-manager="hibernateTransactionManager" />

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
        destroy-method="close">

        <!-- these are C3P0 properties --> 
        <property name="acquireIncrement" value="${database.acquireIncrement}" />
        <property name="minPoolSize" value="${database.minPoolSize}" />
        <property name="maxPoolSize" value="${database.maxPoolSize}" />
        <property name="maxIdleTime" value="${database.maxIdleTime}" />
        <property name="idleConnectionTestPeriod" value="300" />

        <property name="driverClass" value="${database.driver}" />
        <property name="jdbcUrl" value="${database.url}" />
        <property name="user" value="${database.user}" />
        <property name="password" value="${database.password}" />
    </bean>

    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="annotatedClasses">
            <list>
                <value>org.uftwf.schoolvisit.model.VisitModel</value>
                <value>org.uftwf.schoolvisit.model.NameID_lookupModel</value>
                <value>org.uftwf.schoolvisit.model.School_lookupModel</value>
            </list>
        </property>

        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${hibernate.dialect}</prop>
                <prop key="hibernate.show_sql">${hibernate.show_sql}</prop>
                <prop key="hibernate.use_sql_comments">${hibernate.use_sql_comments}</prop>
                <prop key="format_sql">${format_sql}</prop>
                <prop key="hibernate.c3p0.min_size">10</prop>
                <prop key="hibernate.c3p0.max_size">25</prop>
                <prop key="hibernate.c3p0.timeout">600</prop>
                <prop key="hibernate.c3p0.max_statements">0</prop>
                <prop key="hibernate.c3p0.idle_test_period">300</prop>
                <prop key="hibernate.c3p0.acquire_increment">5</prop>
            </props>
        </property>
    </bean>

    <bean id="hibernateTransactionManager"
        class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>
</beans>

Answer 1

Why do you want hibernate to manage the pool? The way it is setup in the second case is the correct way to configure dataSource & hibernate session factory with spring. This will work correctly with spring transaction management.

When you pass the dataSource as a parameter to the sessionFactoryBean the hibernate properties related to the dataSource configuration will be ignored. If you insist upon hibernate managing the pool you can try by removing the dataSource property injection in the AnnotationSessionFactoryBean. The driverClass, jdbcURL etc needs to now be specified as a part of hibernate properties.

From the spring javadoc.

Set the DataSource to be used by the SessionFactory. If set, this will
override corresponding settings in Hibernate properties. If this is
set, the Hibernate settings should not define a connection provider to
avoid meaningless double configuration.

http://static.springsource.org/spring/docs/2.5.x/api/org/springframework/orm/hibernate3/AbstractSessionFactoryBean.html#setDataSource(javax.sql.DataSource)

You can either let spring manage the connection pool (by way of configuring the datasource bean and passing it to sessionFactory) or let hibernate manage it completely. Half & half will not work.