create pdf from images java

create pdf from images java

create pdf from images java

method uses the JPA EntityManager to save the Bid object. But first let s take a quick look at the fourth and final kind of EJB the JPA entity. Listing 2.7 shows how the Bid entity looks.

2. In the Trigger bucket change the EventName dropdown to Loaded, as I do in Figure 7-4.

package ejb3inaction.example.persistence; import import import import import import import import java.io.Serializable; java.sql.Date; javax.persistence.Column; javax.persistence.Entity; javax.persistence.Id; javax.persistence.Table; javax.persistence.GenerationType; javax.persistence.GeneratedValue;

My development servers have 768MB of RAM, and I definitely notice a slowdown in site responsiveness when two or more developers are working on the same server On the other hand, I hardly notice any slowdown when my.

@Entity Marks POJO as entity @Table(name="BIDS") Specifies table mapping public class Bid implements Serializable { private Long bidID; private Long itemID; private Long bidderID; private Double bidAmount; private Date bidDate;

Figure 7-5.

@Id @GeneratedValue(strategy=GenerationType.AUTO) @Column(name="BID_ID") public Long getBidID() { return bidID; } public void setBidID(Long bidID) { this.bidID = bidID; } @Column(name="ITEM_ID") public Long getItemID() { return itemID; } public void setItemID(Long itemID) { this.itemID = itemID; } @Column(name="BIDDER_ID") public Long getBidderID() { return bidderID; }

public void setBidderID(Long bidderID) { this.bidderID = bidderID; } @Column(name="BID_AMOUNT") public Double getBidAmount() { return bidAmount; } public void setBidAmount(Double bidAmount) { this.bidAmount = bidAmount; } @Column(name="BID_DATE") public Date getBidDate() { return bidDate; } public void setBidDate(Date bidDate) { this.bidDate = bidDate; } }

production servers receive significant traffic, which have 8GB RAM and host 20+ sites apiece. Although a number of factors contribute to server speed, increasing the amount of RAM in your host will significantly improve site performance.

4. Still in the Common Properties bucket, click Solid color brush, as I do in Figure 7-6.

You probably have a good idea of exactly how object-relational mapping in JPA works just by glancing at listing 2.7, even if you have no familiarity with ORM tools such as Hibernate. Think about the annotations that mirror relational concepts such as tables, columns, and primary keys. The @Entity annotation signifies the fact that the Bid class is a JPA entity b. Note that Bid is a POJO that does not require a business interface, unlike session and message-driven beans. The @Table annotation tells JPA that the Bid entity is mapped to the BIDS table C. Similarly, the @Column annotations F indicate which Bid properties map to which BIDS table fields. Note that entities need not use getter- and setter-based properties. Instead, the field mappings could have been placed directly onto member variables exposed through nonprivate access modifiers. (You ll learn more about access via entity properties and fields in chapter 7.) The @Id annotation is somewhat special. It marks the bidID property as the primary key for the Bid entity D. Just like a database record, a primary key uniquely identifies an entity instance. We have used the @GeneratedValue annotation with strategy set to GenerationType.AUTO E to indicate that the persistence provider should automatically generate the primary key when the entity is saved into the database.

If you have used EJB 2 you may remember that it was almost rocket science to generate primary key values with container-managed persistence (CMP) entity beans. With EJB 3 JPA, the generation of primary keys is a snap; you have several options, such as table, sequence, identity key, and so on. We ll discuss primary-key generation in chapter 8.

is the color that the LayoutRoot Background will change to when this Behavior fires (see Figure 7-7).

The Bid entity could have been related to a number of other JPA entities by holding direct object references (such the Bidder and Item entities). EJB 3 JPA allows such object reference based implicit relationships to be elegantly mapped to the database. We ve decided to keep things simple for now and not dive into this topic quite so early; we ll discuss entity relationship mapping in chapter 8. Having looked at the Bid entity, let s now turn our attention to how the entity winds up in the database through the PlaceBid bean.