Using JPA in WebSphere to select all rows from the database

I try to implement a web service that uses open JPA to access the data layer I use WebSphere v7.0 0 and JPA 2.0 This service will enable all rows from a small database (about 6 rows, which will not expand much in the future) I try to get all the rows and return them through the user I am now creating a session bean that will retrieve data

I have several JPA objects, one of which (a row representing all the data I want to return) looks like

@Entity
@NamedQueries({
@NamedQuery(name="EmailDomainTrust.getEmailDomains",query="SELECT DOMAIN_NAME,"+ 
        "DESCRIPTION,CONFIRMED_BY,CONFIRMED_DATE" + 
        "FROM EMAIL_DOMAIN_TRUST")          
})
@Table(name="EMAIL_DOMAIN_TRUST")
public class EmailDomainTrust implements Serializable {
    @Id
    @Column(name="EMAIL_DOMAIN_TRUST_ID")
    private long emailDomainTrustId;

    @Column(name="DOMAIN_NAME")
    private String domainName;
}

There's more there, but I don't want it to last long I just thought I'd show some useful variables, maybe some get sets In my session bean, I try to get all the rows

public List<EmailDomainTrust> GetEmailDomains(){
    EntityManagerFactory emf = Persistence.createEntityManagerFactory("");
    EntityManager em = emf.createEntityManager();
    //EntityTransaction userTransaction = em.getTransaction();
    System.out.println("Testing 1..2...3...!");
    List<EmailDomainTrust> ListOfEmailDomains = em.find(EmailDomainTrust.class,arg1)

    try
    {
    }
    catch(Exception e)
    {
    }
    return null;    
}

So far, I have absolutely no snuff However, the online tutorial never describes getting all rows from a table I won't have any parameters for this method, so I won't be able to select by ID or any similar Any suggestion would be good

Solution

You can use namedquery

@NamedQueries({
@NamedQuery(name="EmailDomainTrust.getEmailDomains",query="SELECT e FROM EmailDomainTrust e")          
})

In the session bean:

return em.createNamedQuery("EmailDomainTrust.getEmailDomains",EmailDomainTrust.class).getResultList();