Question

I have a suite of system tests that uses Spring’s JUnit runner, the database config looks like this:

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
    <property name="driverClassName" value="org.postgresql.Driver" />
    <property name="url" value="${clustercatalog.jdbc.url}" />
    <property name="username" value="${clustercatalog.jdbc.username}" />
    <property name="password" value="${clustercatalog.jdbc.password}" />
    <property name="initialSize" value="5" />
    <property name="maxActive" value="50" />
    <property name="poolPreparedStatements" value="true" />
    <property name="maxOpenPreparedStatements" value="100" />
</bean>

<bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    <property name="dataSource" ref="dataSource" />
    <property name="packagesToScan" value="com.xxx" />
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
            <prop key="hibernate.show_sql">${jdbc.show.sql}</prop>
            <prop key="hibernate.id.new_generator_mappings">true</prop>
        </props>
    </property>
    <property name="namingStrategy" ref="namingStrategy" />
</bean>

<bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
    <property name="sessionFactory" ref="sessionFactory" />
</bean>
<tx:annotation-driven />

The test case has a setup in which I run some bash scripts that run pg_restore on the underlying PostgreSQL database from a previously done backup. This is because I need the same state of the database to be the same before every test method. This restore is done in a method annontated with @BeforeTransaction.

The test class is annotated with

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration({ "/systemTests-applicationContext.xml", "/applicationContext.xml" })
@TransactionConfiguration(defaultRollback = false)
@Transactional()

In the test when I execute code that uses the current hibernate session, it doesn’t see the tables that were restored. When I restart the whole test then is sees them, but obviously this is what I want but it proves that the db is fine but Spring/Hibernate got lost when I did pg_restore. I get SQLGrammarException’s that the table does not exist.

I’m looking for a way to manually restart the connection to the DB. How can I achieve that? Should I do it somehow on the sessionFactory or some Spring components?

Answer 1

OK, I resolved the issue. It appears that both Spring and Hibernate are unaware of the changes happening down in the DB and if there are any connections in the DBCP pool they are reused and then the error occurs, because the schema has changed underneath the connection. So I figured that the place to poke during the test when I reset the DBs is the javax.sql.DataSource object provided to the Hibernate SessionFactory. The DBCP BasicDataSource does not have this capability, thus I:

1. created my own wrapper for the dataSource bean.
2. marked the bean as prototype scope so I will not have to construct it myself, every time I need a new one
3. added a refresh method to the wrapping class which calls the applicationContext (autowired to the wrapper class) for the new bean instance
4. injected the wrapper bean to Hibernate’s sessionFactory
5. autowire the wrapper to the test class and when I need in the test call the refresh method

code follows:

@Component
public class RefreshableDataSource implements DataSource {

  @Autowired
  DataSource dataSource;
  @Autowired
  ApplicationContext applicationContext;

  public void refresh() {
    dataSource = (DataSource) applicationContext.getBean("dataSource");
  }

  @Override
  public Connection getConnection() throws SQLException {
    return dataSource.getConnection();
  }

  ...other DataSource methods ...
}

applicationContext.xml:

<bean id="dataSource" scope="prototype" class="org.apache.commons.dbcp.BasicDataSource">
    <property name="driverClassName" value="org.postgresql.Driver" />
            ......
</bean>

<bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    <property name="dataSource" ref="refreshableDataSource" />
    <property name="packagesToScan" value="com.xxx" />
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</prop>
            <prop key="hibernate.show_sql">${jdbc.show.sql}</prop>
            <prop key="hibernate.id.new_generator_mappings">true</prop>
        </props>
    </property>
    <property name="namingStrategy" ref="namingStrategy" />
</bean>