title: How to get DataSource or Connection from JPA2 EntityManager in Java EE 6
body: <p>I have a working application where I use Java EE 6 with EclipseLink for persistence and a PostgreSQL database.</p>
  
  <p>For the User-Registration I want to set the password in PostgreSQL to:</p>
  
  <pre><code>... password = crypt('inputPassword',gen_salt('bf')) ...
  </code></pre>
  
  <p>As I cant use DigestUtils for this, I have to insert the user manually into the DB.
  To keep my application configurable I do not want to query the DataSource with an
  <code>InitialContextInstance.lookup(dataSource)</code> but to extract it (or the Connection) somehow from the EntityManager
  like:</p>
  
  <pre><code>DataSource ds = entityManagerInstance.someFunctionThatReturnsADataSourceOrConnection();
  </code></pre>
  
  <p>Or would it be possible to use createNativeQuery or something similar in conjuntion
  with a prepared statement to protect against injections?</p>