title: Griffon & JPA : environment configuration in persistence.xml
body: <p>Using Griffon 1.2 and JPA is there any way to configure the persistence.xml with environmental properties - so I can have a different jdbc.url for dev/test/prod ?</p>
  
  <p>i.e. conf/metainf/persistence.xml</p>
  
  <pre><code> &lt;property name="javax.persistence.jdbc.url"      value="${javax.persistence.jdbc.url}" /&gt;
  </code></pre>
  
  <p>I was hoping something like this would work in JpaConfig.groovy</p>
  
  <pre><code>environments {
      development {
          persistenceUnit {
              entityManager {
                  // EntityManager properties go here
                  javax.persistence.jdbc.url = 'jdbc:h2:mem:sample'
              }
          }
      }...
  </code></pre>
  
  <p>I could create multiple duplicate persistence xml files and I believe I can specify the active persistence unit in JpaConfig.groovy. Or is there some other way to parameterize the JPA configuration per environment?</p>
  
  <p>Thanks</p>