bcd session 02

8/10/2019 BCD Session 02

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Business Component Development Using EJB Technologies

In this session, you will learn to:

Describe the auction application use cases

Define the domain objects of the auction application

Describe the implementation model for the auction system

Objectives


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The auction application has the following users:

Seller

Bidder

Administrator

The following figure shows the actors and the use casesassociated with each actor.

Auction Application Use Cases


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The use cases implemented by auction application are:

Create-auction

Close-auction

Bid-on-auction

Auction Application Use Cases (Contd.)


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The Auction Domain Object

The Auction domain object represents a single online

auction within the auction application.

The following figure shows the Auction domain object.


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The Auction Domain Object (Contd.)

The Auction domain object contains the following attributes:

The auctionID

The startAmount

The increment

The statusThe openTime

The closeTime

Each Auction domain object contains the following

relationships with the other domain objects:

The item: Represents the item for sale in the auctionThe seller: Represents the AuctionUser object who is selling

the item

The bids: Represents the collection of bids placed on the

auction


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The AuctionUser Domain Object

The AuctionUser domain object represents either a seller or

a bidder within the auction application.

The following figure shows the AuctionUser domain object.




The AuctionUser Domain Object (Contd.)

The AuctionUser domain object contains the following

attributes:

The auctionUserID

The displayName

The emailEach AuctionUser domain object contains the following

relationships with the other domain objects:

The auctions: Represents the auctions that the auction user

has participated in as a seller

The bids: Represents the collection of bids placed by theauction user




The Bid Domain Object

The Bid domain object represents a purchase offer on an

auction sale item.

The following figure shows the Bid domain object.


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The Bid Domain Object (Contd.)

The Bid domain object contains the following attributes:

The bidID

The amount

The bidTime

The approvalEach Bid domain object contains the following relationships

with other domain objects:

The auction: Represents the auction associated with the bid

The bidder: Represents the auction user who placed the bid


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The Item Domain Object

The Item domain object represents the article offered for

sale in an auction.

The following figure shows the Item domain object.


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The Item Domain Object (Contd.)

The Item domain object contains the following attributes:

The itemID

The description

The image


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The BookItem Domain Object

The BookItem domain object:

Represents the book item.

Inherits from the Item domain object.

The following figure shows the BookItem domain object.


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The BookItem Domain Object (Contd.)

The BookItem domain object contains the following

attributes:

The title

The author


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Examining the Implementation Model

The Auction system is based on the Java EE technology

and the EJB technology architecture.

The following figure shows the preliminary design of the

auction system implementation.


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Examining the Implementation Model (Contd.)

The middle-tier consists of a:

Business Core

Persistence Service

The middle-tier subsystems consists of the:

AuctionManager session bean classHelper objects

Persistence entities


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The following figure shows the persistence entities used by

the auction application.


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The EJB container uses a persistence provider to manage

entity instances.

The persistence provider is responsible for synchronizing

the data held in entity instances it manages with data in the

EIS tier.


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In this session, you learned that:

The auction application has the following users:

Seller

Bidder

Administrator

The auction application implements the following use cases:

create-auction

close-auction

bid-on-auction

Summary


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The auction application is modeled using the following domain

objects:

The Auction domain object

The AuctionUser domain object

The Bid domain object

The Item domain objectThe BookItem object

The auction system is based on the Java EE technology and

the EJB technology architecture.

The middle tier consists of a business core and persistence

service.Each EJB container is associated with a persistence provider.

Summary (Contd.)

bcd session 02

Documents