Java Reference
In-Depth Information
Listing 3.8
The
DesperateCheeseOffer
class
public class DesperateCheeseOffer implements SpecialOffer {
private Inventory inventory;
Inventory gets
injected
public void setInventory(Inventory inventory) {
this.inventory = inventory;
}
@Override
public String getDescription() {
return "A wonderful surprise for someone cheesy.";
}
@Override
public Food getOfferFood() {
List<Food> cheeses =
inventory.getFoodsWhoseNameContains("cheese", 1);
Food leastPopularCheese = cheeses.get(0);
return leastPopularCheese;
Food list already
sorted, so you can
take first food
}
}
Build a bundle containing the blueprint.xml and the
DesperateCheeseOffer
class (and
a manifest). When you drop this bundle into the load directory, you should find that the
front page of the Fancy Foods shop has gotten a lot more exciting (figure 3.10).
If you get the persistence wrong, you'll find that the cheese offer isn't listed. If the
dependencies of the
DesperateCheeseOffer
aren't available, Blueprint won't instanti-
ate the cheese offer and it won't publish a
SpecialOffer
service. Using the
OSG
i con-
sole's
ss
and
bundle
commands can usually help track down the weak link in the
dependency chain.
After you've fixed and rebuilt the misconfigured bundle, you'll find that things
kick into life without any restarts or manual interventions on your part. All that's
required is a refresh of the web page for the cheese offer to appear. (And if you stop
Figure 3.10
After the addition of the cheese department, datasource, and persistence bundles, the
Fancy Foods shop has a new special offer, driven from the cheese stock levels in the database.
