Product Version: NetBeans IDE Dev (Build 201102240001)
Java: 1.6.0_22; Java HotSpot(TM) 64-Bit Server VM 17.1-b03-307
System: Mac OS X version 10.5.8 running on x86_64; MacRoman; en_US (nb)
Userdir: /Applications/NetBeans/userdirs/7.0-20110222

The code generated by Use Entity Manager in a session bean is inconsistent between Ant and Maven projects. For more details, see issue 185682.

When you use the Use Entity Manager to generate code in an Ant project, the IDE generates the following:

@PersistenceContext(unitName = "WebAppJUnitPU")
private EntityManager em;

public void persist(Object object) {
    em.persist(object);
}

When you use the same wizard in a Maven project, the code generated by the IDE is different:

@PersistenceContext(name = "persistence/LogicalName", unitName = "com.mycompany_mavenwebapp2_war_1.0-SNAPSHOTPU")
public class NewSessionBean {
    @Resource
    private javax.transaction.UserTransaction utx;

    protected void persist(Object object) {
        try {
            Context ctx = (Context) new InitialContext().lookup("java:comp/env");
            utx.begin();
            EntityManager em = (EntityManager) ctx.lookup("persistence/LogicalName");
            em.persist(object);
            utx.commit();
        } catch (Exception e) {
            Logger.getLogger(getClass().getName()).log(Level.SEVERE, "exception caught", e);
            throw new RuntimeException(e);
        }
    }