Question

I have a simple web app developed with Spring 3 and Hibernate 3 deployed on tomcat 7. My application works fine till the Database server is shutdown. After the database server is turned on again I expected the app to work but I needed to restart tomcat to make the appl work again. If not I get the following exception

org.springframework.web.util.NestedServletException: Request processing failed; nested >exception is org.springframework.jdbc.UncategorizedSQLException: Hibernate operation: could ?>not execute query; uncategorized SQLException for SQL

A snapshot of the database properties used is below

<bean id="OradataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-    method="close">
    <property name="driverClassName" value="oracle.jdbc.OracleDriver"/>
    <property name="url" value="xyz"/>
    <property name="username" value="xyz"/>
    <property name="password" value="xyz"/>       
</bean>
<bean id="OraDbHibernateProperties" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
    <property name="properties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.Oracle10gDialect</prop>
            <prop key="log4j.logger.net.sf.hibernate">trace</prop>
        </props>
    </property>
</bean>

Any help is appreciated. Thanks

Answer 1

You need to add 2 more properties.

<property name="validationQuery" value="SELECT 1" />
<property name="testOnBorrow" value="true" />

1. Validation query – to validate connections from the pool before returning them to the caller.
2. testOnBorrow – if set to true, connections will be validated before being borrowed from pool. If the connection is not valid, it will be removed from the pool and another connection will be borrowed.