Sunday, September 04, 2005

Commonly Asked Definitions

I would like to post here, some Commonly Asked Definitions. If you would like more definitions, please post your comments to this blog entry.

A. J2EE Patterns
(a) Software Design Pattern: It's a repeatable solution for a commonly-occuring software problem. Definition credit goes to the book Head First Servlets and JSP.

(b) DataAccessObject (DAO): The DAO implements the access mechanism required to work with the data source. The data source could be a persistent store like an RDBMS, an external service like a B2B exchange, a repository like an LDAP database, or a business service accessed via CORBA Internet Inter-ORB Protocol (IIOP) or low-level sockets. The business component that relies on the DAO uses the simpler interface exposed by the DAO for its clients. The DAO completely hides the data source implementation details from its clients. Because the interface exposed by the DAO to clients does not change when the underlying data source implementation changes, this pattern allows the DAO to adapt to different storage schemes without affecting its clients or business components. Essentially, the DAO acts as an adapter between the component and the data source.

(c) BusinessObject (BO): represents the data client. It is the object that requires access to the data source to obtain and store data. A BusinessObject may be implemented as a session bean, entity bean, or some other Java object, in addition to a servlet or helper bean that accesses the data source.

(d) DataSource: This represents a data source implementation. A data source could be a database such as an RDBMS, OODBMS, XML repository, flat file system, and so forth. A data source can also be another system (legacy/mainframe), service (B2B service or credit card bureau), or some kind of repository (LDAP).

(e) TransferObject: This represents a Transfer Object used as a data carrier. The DataAccessObject may use a Transfer Object to return data to the client. The DataAccessObject may also receive the data from the client in a Transfer Object to update the data in the data source. Definitions (b) to (e) credit, goes to Sun Developer Network.

For more information on Design Patterns, refer the site Data and Object Factory
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1 Comments:

Anonymous Tejaswini said...

How to use cactus's eclipse plugin to test struts application?

I want to unit test ActionForm,Action Class and other mappings thru' eclipse using cactus. If anyone knows it,please reply asap.
Thankx in advance
Regards,
Tejaswini

10:45 AM  

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