Integrate EJBs with Web Module Model Objects

The InventoryModel uses the StoreItem class to represent inventory items, so that it does not expose the Inventory EJB interface. That means will need additional helper classes to convert an Inventory collection to StoreItem s:

private StoreItem InventoryToStoreItem(Inventory inv) {




return new StoreItem(inv);




}




private Collection InventoryToStoreItems(Collection c) {




Vector v = new Vector();




try {




Iterator i = c.iterator();




while ( i.hasNext() ) {




Inventory inv = (Inventory) i.

next

();




v.add(InventoryToStoreItem(inv));




}




return v;




} catch (Exception e) {




throw new EJBException(e);




}




}

The InventoryModel offers two finder methods, which do nothing more than delegate to InventoryHome finders , then convert the resulting Inventory objects to StoreItem objects:

public Collection findByCategory(String category) {




try {




int icategory = getCategoryKeyFromString(category);




Collection c = getInventoryHome().findByCategory(icategory);




return InventoryToStoreItems(c);




} catch (Exception e) {




throw new EJBException(e);




}




}




public StoreItem findById(String id) {




try {




InventoryKey key = new InventoryKey(id);




Inventory inv = (Inventory) getInventoryHome().findByPrimaryKey(key);




return InventoryToStoreItem(inv);




} catch (Exception e) {




throw new EJBException(e);




}




}

and of course here's the EJB lookup:

private final static String INVENTORY_HOME_NAME=




"java:comp/env/ejb/plantsby/InventoryHome";




private static InventoryHome inventoryHome;




private InventoryHome getInventoryHome() {




if ( inventoryHome == null ) {




try {




InitialContext ctx = new InitialContext();




inventoryHome = (InventoryHome) ctx.lookup(INVENTORY_HOME_NAME);




} catch (Exception e) {




e.printStackTrace();




throw new EJBException(e);




}




return inventoryHome;




} else {




return inventoryHome;




}




}

OrderModel

The OrderModel object has only a single business method, addOrder() , which is a simple delegation to the Order EJB. Note we have not implement supported for credit cards. We'll just fake it for now. Adding credit-card support is beyond what we'll cover in this chapter:

public String addOrder(CustomerInfo c, Vector orderItems) {




try {




Order o = getOrderHome().create(c.getEmail(), c.getName(), c.getAddr1(),




c.getAddr2(), c.getCity(), c.getState(),




c.getZipcode(), c.getPhone(), c.getName(),




c.getAddr1(), c.getAddr2(), c.getCity(),




c.getState(), c.getZipcode(), c.getPhone(),




"NO CREDIT CARD", "NO CC NUMBER",




"NO CC MONTH", "NO CC YEAR",




"NO CARD HOLDER", 1, // shipping method




orderItems);




return o.getID();




} catch (Exception e) {




throw new EJBException(e);




}




}

and the getOrderHome() method and support:

private final static String ORDER_HOME_NAME =




"java:comp/env/ejb/plantsby/OrderHome";




private static OrderHome inventoryHome;








private OrderHome getOrderHome() {




if ( inventoryHome == null ) {




try {




InitialContext ctx= new InitialContext();




inventoryHome= (OrderHome) ctx.lookup(ORDER_HOME_NAME);




} catch (Exception e) {




e.printStackTrace();




throw new EJBException(e);




}




return inventoryHome;




} else {




return inventoryHome;




}




}

CustomerModel

The customer model has two methods to implement: one to add a customer; one to find one. These methods will primarily use the Customer EJB's finder methods. The addCustomer() method is the exception: it uses the Customer method update() to update an existing Customer to account for changes the user may have made to their name , address, etc:

public void addCustomer(CustomerInfo i) {




CustomerKey key = new CustomerKey(i.getEmail());




try {




Customer c = getCustomerHome().findByPrimaryKey(key);




c.update( i.getFirstName(), i.getLastName(),i.getAddr1(), i.getAddr2(),




i.getCity(), i.getState(), i.getZipcode(), i.getPhone() );




} catch ( FinderException e ) {




try {




Customer c = getCustomerHome().create(key, "PASSWORD", i.getFirstName(),




i.getLastName(), i.getAddr1(),




i.getAddr2(), i.getCity(),




i.getState(),i.getZipcode(),




i.getPhone());




} catch ( CreateException ex) {




throw new EJBException("Could not create new customer");




}




}




}




public CustomerInfo getCustomer(String emailKey) {




CustomerKey key = new CustomerKey(emailKey);




try {




Customer c= getCustomerHome().findByPrimaryKey(key);




CustomerInfo ci= new CustomerInfo();




ci.setEmail(c.getCustomerId());




ci.setFirstName(c.getFirstName());




ci.setLastName(c.getLastName());




ci.setAddr1(c.getAddr1());




ci.setAddr2(c.getAddr2());




ci.setCity(c.getCity());




ci.setState(c.getState());




ci.setZipcode(c.getZip());




ci.setPhone(c.getPhone());




return ci;




} catch ( FinderException e ) {




throw new EJBException("Could not find customer with key " + emailKey);




}




}

Finally, the EJB lookup:

private final static String Customer_HOME_NAME =




"java:comp/env/ejb/plantsby/CustomerHome";




private static CustomerHome CustomerHome;








private CustomerHome getCustomerHome() {




if ( CustomerHome == null ) {




try {




InitialContext ctx = new InitialContext();




CustomerHome= (CustomerHome) ctx.lookup(Customer_HOME_NAME);




} catch (Exception e) {




e.printStackTrace();




throw new EJBException(e);




}




return CustomerHome;




} else {




return CustomerHome;




}




}

Declare EJB References

Finally, and as the last step in connecting our EJBs to the model beans in our web module, let's declare the EJB references we require in PlantsByWebSphereWAR . Do this by opening the Deployment Descriptor editor for the PlantsByWebSphereWAR . Select the Resources tab in the editor.

The screen layout is slightly different because it's a web module, but otherwise it's same idea as when we linked up the EJB references for the EJB module: