What to put into jta-data-source of persistence.xml?

Question

What value should I place into <jta-data-source> of my persistence.xml?

In glassfish admin panel I created a datasource name "abcDS". In my jndi.properties (inside src/test/resources) I defined it like this:

[...]
abcDS=new://Resource?type=DataSource
abcDS.JdbcDriver=org.hsqldb.jdbcDriver
abcDS.JdbcUrl=jdbc:hsqldb:mem:testdb
abcDS.JtaManaged=true
[...]

What shall I place into persistence.xml? I've found a lot of variants in the Net, like: "jdbc/abcDS", "java:/abcDS", "abcDS". Which one is right? And is there some rule for this? I understand that it's related to JNDI, but...

I'm trying to create EMF in my unit test:

EntityManagerFactory emf = Persistence.createEntityManagerFactory("abc");

This is what I'm getting in log:

[...]
SEVERE: Could not find datasource: abcDS javax.naming.NameNotFoundException: 
    Name "abcDS" not found.
at org.apache.openejb.core.ivm.naming.IvmContext.federate(IvmContext.java:193)
at org.apache.openejb.core.ivm.naming.IvmContext.lookup(IvmContext.java:150)
at org.apache.openejb.core.ivm.naming.ContextWrapper.lookup(ContextWrapper.java:115)
at javax.naming.InitialContext.lookup(InitialContext.java:392)
[...]

Answer 1

The problem is that Persistence.createEntityManagerFactory("abc") is the "do it yourself" API and doesn't take advantage of the Embedded EJB Container. You can get a container managed EntityManager in your test case very easily.

Just as with the related jndi/datasource question I recommend you check out the examples in the examples.zip. They're all designed to take the struggle out of getting started.

Here's a snippet from the testcase-injection example which shows how you can get an EntityManager and other things from the container for use in a test.

First, add an empty ejb-jar.xml or application-client.xml to your test to turn on scanning for your test code:

• src/test/resources/META-INF/application-client.xml

Then, annotate your test case with @org.apache.openejb.api.LocalClient and use the standard JavaEE annotations for the actual injection.

@LocalClient
public class MoviesTest extends TestCase {

    @EJB
    private Movies movies;

    @Resource
    private UserTransaction userTransaction;

    @PersistenceContext
    private EntityManager entityManager;

    public void setUp() throws Exception {
        Properties p = new Properties();
        p.put(Context.INITIAL_CONTEXT_FACTORY, "org.apache.openejb.client.LocalInitialContextFactory");
        p.put("movieDatabase", "new://Resource?type=DataSource");
        p.put("movieDatabase.JdbcDriver", "org.hsqldb.jdbcDriver");
        p.put("movieDatabase.JdbcUrl", "jdbc:hsqldb:mem:moviedb");

        InitialContext initialContext = new InitialContext(p);

        // Here's the fun part
        initialContext.bind("inject", this);
    }

As movieDatabase is the only DataSource that we've setup, OpenEJB will automatically assign that DataSource to your persistence unit without the need to modify your persistence.xml. You can even leave the <jta-data-source> or <non-jta-data-source> empty and OpenEJB will still know what to do.

But for the sake of completeness, here's how this particular application has defined the persistence.xml

<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="1.0">

  <persistence-unit name="movie-unit">
    <jta-data-source>movieDatabase</jta-data-source>
    <non-jta-data-source>movieDatabaseUnmanaged</non-jta-data-source>
    <class>org.superbiz.testinjection.Movie</class>

    <properties>
      <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)"/>
    </properties>
  </persistence-unit>
</persistence>

Then the fun part, using it all together in tests

public void test() throws Exception {

    userTransaction.begin();

    try {
        entityManager.persist(new Movie("Quentin Tarantino", "Reservoir Dogs", 1992));
        entityManager.persist(new Movie("Joel Coen", "Fargo", 1996));
        entityManager.persist(new Movie("Joel Coen", "The Big Lebowski", 1998));

        List<Movie> list = movies.getMovies();
        assertEquals("List.size()", 3, list.size());

        for (Movie movie : list) {
            movies.deleteMovie(movie);
        }

        assertEquals("Movies.getMovies()", 0, movies.getMovies().size());

    } finally {
        userTransaction.commit();
    }
}