title: Mocking dataSource during Unit Testing
body: <p>I would like to unit test my DB independent web layer controllers even if the database is down.</p>
  
  <p>But the <code>transactionManager</code> bean instantiation fails because the connection cannot be achieved by the bean <code>dataSource</code> with the given DB credentials.</p>
  
  <p>Also, I have used <code>@Transactional</code>, <code>@AfterTransaction</code> and <code>@BeforeTransaction</code> annotations which I do not want to remove.</p>
  
  <p>Is there a way to define a dummy (or mock) <code>dataSource</code> where I need not provide any database credentials but still get my <code>transactionManager</code> bean to be instantiated?</p>