c3p0_spring_config.xml

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
	<!-- access -->
	<property name="driverClass" value="${db.driverclass}" />
	<property name="jdbcUrl" value="${db.url}" />
	<property name="user" value="${db.user}" />
	<property name="password" value="${db.password}" />
	<!-- pool sizing -->
	<property name="initialPoolSize" value="3" />
	<property name="minPoolSize" value="6" />
	<property name="maxPoolSize" value="25" />
	<property name="acquireIncrement" value="3" />
	<property name="maxStatements" value="0" />
	<!-- retries -->
	<property name="acquireRetryAttempts" value="30" />
	<property name="acquireRetryDelay" value="1000" /> <!-- 1s -->
	<property name="breakAfterAcquireFailure" value="false" />
	<!-- refreshing connections -->
	<property name="maxIdleTime" value="180" /> <!-- 3min -->
	<property name="maxConnectionAge" value="10" /> <!-- 1h -->
	<!-- timeouts and testing -->
	<property name="checkoutTimeout" value="5000" /> <!-- 5s -->
	<property name="idleConnectionTestPeriod" value="60" /> <!-- 60 -->
	<property name="testConnectionOnCheckout" value="true" />
	<property name="preferredTestQuery" value="SELECT 1" />
        <property name="testConnectionOnCheckin" value="true" />
</bean>

database.properties

# DB settings
# ~~~~~~~~~~~~
# H2
db.driver = org.h2.Driver
db.url = jdbc:h2:mem:myDBname
db.user = sa
db.password = 

# MySQL
#db.driver = com.mysql.jdbc.Driver
#db.url = jdbc:mysql://localhost:3306/myDBname
#db.user = mysql
#db.password = mysql

# PostegrSQL
#db.driver = org.postgresql.Driver
#db.url = jdbc:postgresql://localhost:5432/myDBname?searchpath=public
#db.user = postgresql
#db.password = postgresql