Dev Thoughts

I have pretty strong opinions about java annotations usages. Like many others, I feel that this feature is being overly misused for all sort of purposes, without putting too much thought whether it is the right thing to do or not. It sort of reminds me of how XML was 4-5 years ago… soon someone will come up with a scripting language for annotations and we’ll all be very happy…

I decided to do a small experiment. I thought to myself… let’s have a POJO - a simple POJO. I want to persist it, index it, and not to forget, to de/serialize it from/to xml. Then I thought, why not use EJB3/hibernate annotations for persisting and indexing and that other lib I heard of… what’s the name… ah yes… X2J… to do the xml stuff…

So I started of with this:

public class User {

    private Long id;
    private String firstName;
    private String lastName;
    private Address address;

    // constructors...

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public Address getAddress() {
        return address;
    }

    public void setAddress(Address address) {
        this.address = address;
    }
}

And ended up with:

@Entity
@Table(name = "account")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(
    name = "account_type",
    discriminatorType = DiscriminatorType.STRING
)
@Indexed(index="indexes/users")
@Element
public class User {

    private Long id;
    private String firstName;
    private String lastName;
    private Address address;

    // constructors...

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "account_id_seq")
    @Keyword(id=true)
    @Attribute
    @PrimaryKey
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    @Basic
    @Column(name = "first_name", nullable = false, length = 50)
    @Text(name="firstName")
    @Attribute
    public String getFirstName() {
        return firstName;
    }

    @NotNull
    @Length(min = 1, max = 50)
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    @Basic
    @Column(name = "last_name", nullable = false, length = 50)
    @Text(name="lastName")
    @Attribute
    public String getLastName() {
        return lastName;
    }

    @NotNull
    @Length(min = 1, max = 255)
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    @Embedded
    @InnerElement
    @ArrayElement(label=false)
    public Address getAddress() {
        return address;
    }

    @NotNull
    @Valid
    public void setAddress(Address address) {
        this.address = address;
    }
}

Holycrap! Dude… where’s my class?!?!?!

This entry was posted on Thursday, February 16th, 2006 at 2:13 am and is filed under Java. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.