Rockhopper Blog

I’ve been taking a legacy codebase, putting testing in place and refactoring. For DB access I retrofitted the persistence classes to be injected via Spring with a DataSource instead of looking them up via JNDI. IN my Spring context I defined a PlatformTransactionManager.

<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource"
scope="singleton" p:driverClassName="${jdbc.driverClassName}"
p:url="${jdbc.url}" p:username="${jdbc.username}"
p:password="${jdbc.password}" />

<!-- has a property named dataSource which we autowire -->
<bean id="transactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
autowire="byName" />

Then I refer to it in the the test case class.

@TransactionConfiguration(transactionManager = "transactionManager", defaultRollback = true)
public class MyTestCases extends
   AbstractTransactionalJUnit4SpringContextTests {

etc.

Sure enough the console blathered on about starting and rolling back the transaction. The problem is, it wasn’t. It was just saying it did.

How do I know? I checked.

int nrowsInMyTable;

@BeforeTransaction
public void onSetUpInTransaction() throws Exception   {
   nrowsInMyTable = countRowsInTable("SomeTable");
}

@AfterTransaction
public void verifyFinalDatabaseState()   {
   int rows = countRowsInTable("SomeTable");
   assertEquals(nrowsInMyTable, rows);
}

So what was the problem?

I was doing this like every other J(2)EE programmer.

connection = this.dataSource.getConnection();

But with Spring you need to do this instead to associate the transaction thread with the datasource.

connection = DataSourceUtils.getConnection(this.dataSource);

and

DataSourceUtils.releaseConnection(conn, this.dataSource);

Then it worked.

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