Hi Benjamin,

If you access OpenJPA from your servlet directly, then you use the EntityTransaction to begin and commit transactions. But if you delegate to a SessionBean, the bean's transaction properties begin and commit transactions without your writing any code.

With regard to the schema mismatch, without seeing the orm metadata and the table definition it's hard to figure out where the problem is. The apache servers remove attachments from emails. Can you try pasting the text of the orm definition and the class definition for the Promotion class into the message?

Regards,

Craig

On Jun 11, 2009, at 3:06 PM, Benjamin S Vera-Tudela wrote:

I am new to JPA and am having a problem with WAS CE 2.1.1.2 (based on Geronimo) and after two days of researching, I am unable to identify the issue. Perhaps someone may know what the problem is by the info provided below. I have included my persistence.xml and deployment plan files in case someone wants to take a peek at these.

For background, my app is a simple J2EE app with accounts, products, and promotions among other related objects. After successful deployment on WAS CE 2.1.1.2, I can access the main JSPs and servlet, but upon posting data that is used to update the JPA entities via a Stateless Session Bean (SSB) invoked from the servlet, I get the several instances of the following message for various entity fields:

672 MyDataAppJPA WARN [http-0.0.0.0-8080-1] openjpa.jdbc.Schema - Existing column "CODE" on table "APP.PROMOTION" is incompatible with the same column in the given schema definition. Existing column:
Full Name: PROMOTION.CODE
Type: char
Size: 8
Default: null
Not Null: false
Given column:
Full Name: Promotion.code
Type: varchar
Size: 255
Default: null
Not Null: false

These are followed by the exception:

<openjpa-1.2.1-r2180:4612 nonfatal user error> org.apache.openjpa.persistence.InvalidStateException: You cannot access the EntityTransaction when using managed transactions.

Any idea what may be causing these errors? Any hints are appreciated.

========================================================================================================================================

For some further background on the app and how the pieces interact, the app contains:

1) A Web component with a Servlet and JSPs acting as the web front that interface with the end user
2) An EJB component with a Stateless Session Bean (SSB) used to handle the transaction boundaries for "complex" business logic using the JPA entitites
3) A JPA component containing all the Entity Beans for my application and "Entity Managers" generated with RAD (see below for an example)

My servlet instantiates the SSB and Entity Manager as follows:

<graycol.gif>Servlet Code:
public class MyDataAppServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

@EJB
private MyDataAppBeanLocal bean; // Stateless Session Bean reference
private AccountManager accountMgr = new AccountManager(); // Entity Manager for the Account JPA entity

...
}


A piece of my SSB code follows:

<graycol.gif>SSB Code:
@Stateless
public class MyDataAppBeanImpl implements MyDataAppBeanLocal {
static java.util.Random rnd = new java.util.Random(System.currentTimeMillis());

@PersistenceContext(unitName="MyDataAppJPA")
protected EntityManager em;

@Resource SessionContext ctx;

public void createAccount(String id, String password, String name, String type String address1, String address2, String city, String state, String zipCode)
throws Exception {
System.out.println(">>>> Creating account transaction");
Account account = new Account();
account.setLoginId(id);
account.setPassword(password);
account.setName(name);
account.setType(type);

Address address = new Address();
address.setAddress1(address1);
address.setAddress2(address2);
address.setCity(city);
address.setState(state);
address.setZipCode(zipCode);

account.setAddress(address);

em.persist(address);
em.persist(account);
}

My servlet may also perform simple updates on JPA entity fields using the object's "entity manager" (which I actually created using RAD tooling as I was learning JPA). For instance, from the sample servlet code above, the accountMgr can be used on an Account JPA entity to persist a simple field update such as the account's last login timestamp:

<graycol.gif>Updating JPA with Entity Manager:
try {
account.setLastLogin(new Timestamp(System.currentTimeMillis()));
accountMgr.updateAccount(account);
} ....


The AccountManager looks like this (I have commented out annotations generated from RAD that are tied to WAS and not available in WAS CE such as @JPAManager and @Action):

<graycol.gif>Account Manager created with RAD:
//XXX:@JPAManager(targetEntity=com.data.jpa.Account.class)
@SuppressWarnings("unchecked")
public class AccountManager {

private EntityManager getEntityManager() {
EntityManagerFactory emf = Persistence
.createEntityManagerFactory("MyDataAppJPA");
return emf.createEntityManager();
}

//XXX:@Action(Action.ACTION_TYPE.UPDATE)
public String updateAccount(Account account) throws Exception {
EntityManager em = getEntityManager();
try {
em.getTransaction().begin();
account = em.merge(account);
em.getTransaction().commit();
} catch (Exception ex) {
try {
if (em.getTransaction().isActive()) {
em.getTransaction().rollback();
}
} catch (Exception e) {
ex.printStackTrace();
throw e;
}
throw ex;
} finally {
em.close();
}
return "";
}
}

And finally here is persistence.xml and deployment plan for my JPA and app.

(See attached file: persistence.xml)(See attached file: MyDataApp.xml)



Benjamin S. Vera-Tudela
SWG Middleware Strategy
Ph: (512)-286-9073 T/L 363-9073
E-Mail: bveratudela@us.ibm.com


Craig L Russell

Architect, Sun Java Enterprise System http://db.apache.org/jdo

408 276-5638 mailto:Craig.Russell@sun.com

P.S. A good JDO? O, Gasp!