Evolutionary Dawn

March 21, 2008

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@Entity
public class Customer implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
        private Long id;
    @Column(name="c_name")
    private String name;
    @Embedded
    private Address address;
    //Magical get/set methods here
}

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@Embeddable
public class Address implements Serializable {
    private String streetLineOne;
    private String streetLineTwo;
    private String city;
    private String state;
    private String postalCode;
    private String country;
    //Magical get/set methods here
}

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@Entity
@Table(name="belt_order_header")
public class OrderHeader implements Serializable {
 
    public enum OrderStatus { BID, ORDER, INVOICE, HOLD, CONSIGNMENT }
 
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE)
    private Long id;
    private OrderStatus status;
    private String poNumber;
    private String internalNotes;
    private ShipVia shipVia;
    @Embedded
    @AttributeOverrides( {
        //Magical Overrides
    } )
    private Address billTo;
    @Embedded
    @AttributeOverrides( {
        //Magical Overrides
    } )
    private Address shipTo;
 
    @ManyToOne private Customer customer;
    @ManyToOne private Branch billingBranch;
    @ManyToOne private Branch fabricationBranch;
     //Magical get/set methods here
}

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public OrderHeader createOrderHeader(Customer customer) {
    OrderHeader oh = new OrderHeader();
    oh.setBillTo(customer.getAddress());
    oh.setShipTo(customer.getAddress());
    em.persist(oh);
    return oh;
}

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public static Address copy(final Address address) {
    Address copy = new Address();
    copy.setStreetLineOne(address.getStreetLineOne());
    copy.setStreetLineTwo(address.getStreetLineTwo());
    copy.setCity(address.getCity());
    copy.setState(address.getState());
    copy.setCountry(address.getCountry());
    copy.setPostalCode(address.getPostalCode());
    return copy;
}

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public OrderHeader createOrderHeader(Customer customer) {
    OrderHeader oh = new OrderHeader();
    oh.setBillTo(Address.copy(customer.getAddress()));
    oh.setShipTo(Address.copy(customer.getAddress()));
    em.persist(oh);
    return oh;
}

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public BeltType find(Object pk) {
    BeltType beltType = (BeltType) em.find(BeltType.class, pk);
    try {
        em.refresh(beltType);
    }
    catch(EntityNotFoundException ex) {
        return null;
    }
    if(beltType == null)
        return null;
    loadLazyInitializations(beltType);
    return beltType;
}

7 Comments »

1. I’ve done a spotlight on your entry at TheAquarium. Posted for this evening. I’ll also tell Sekhar to send you an email so you can help other peole migrating. - eduard/o

   Comment by Eduardo Pelegri-Llopart — March 23, 2008 @ 11:59 am

2. Your code is unreadable (because unindented).

   S.

   Comment by Stefane Fermigier — March 24, 2008 @ 1:49 am

3. Sorry for the issue. I believe my last few edits should resolve your code readability issue.

   Comment by admin — March 24, 2008 @ 8:51 am

4. David, thanks for sharing your migration experience. These would be great additions to the GlassFish migration guide http://wiki.glassfish.java.net/Wiki.jsp?page=M2GMigrationGuide . The guide is intended to help people with migrating to GlassFish ( see announcement http://forums.java.net/jive/thread.jspa?messageID=261465 ). So,I created links to the three issues in this blog from the migration guide. It would be very helpful if you could contribute your code example/text inline in the migration guide. It is in community based wiki format. So you can edit yourself. If you have any questions, please email at sekhar@dev.java.net. Thanks !

   Also, on issue 3, what is being done differently on JBoss ?

   Comment by Sekhar Vajjhala — March 24, 2008 @ 10:04 am

5. Sekhar,
   Thank you for your post. If I have time I will contribute it to the Wiki but it might be a month or 2 since I am up againest a deadline.

   On Issue #3
   In JBoss you would not have to em.refresh(object). It appears that there is no caching used on JBoss by default. On em.find(class,object) would actually pull the data from the DB.

   Comment by admin — March 24, 2008 @ 10:18 am

6. Hi David,

   Thanks for this great overview.

   Using NetBeans to develop JEE applications, Entities are generated by default with the equals method overridden. This is of little use when migrating an existing project from JBoss to GlassFish, but for new projects that are developed for GlassFish this might be a solution.

   Greets, Wouter

   Comment by Wouter van Reeven — March 25, 2008 @ 6:25 am

7. Thanks Wouter for the post,
   The comment I made about override must be taken in context of it being un-tested.
   Meaning that I am blaming my issue on not having equals(Object) @Override but have
   not verified that it is actually causing my issue. What I do know, is that I have a work around.

   But now that you have me on my “Soap Box”.

   Generally overriding equals(Object) and hashcode() methods are my biggest annoyance
   with J2EE spec. Not all “Entities” can have business keys that make them equal because
   certain business rules prevent it even if all the data attributes are equal. Since I am a
   bit of a neanderthal this whole idea of overriding those methods has never made sense.
   Please some write me a comment on how to do this properly so I myself can move on
   from the stone age.

   Comment by admin — March 25, 2008 @ 6:41 am

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