N-tier architecture applications


In the past, two-tier applications commonly known as client/server applications were very common. In a two-tier application the client side logic is responsible for everything from presentation, business logic to database access. The client/server applications are not scalable, are difficult to maintain and enhance due to tight coupling between the presentation layer, business logic and the database access. Overall the two tier applications are not scalable and are not suitable for internet based applications. With the growing popularity of J2EE framework, the development of an n-tier application became easier and all the negatives of a client/server application development were well taken care. A J2EE framework provides standardized modular components and a complete set of services to those components. More-over application behavior such as security and multithreading are handled automatically. Using J2EE to develop n-tier applications involves breaking the two-tier architecture into multiple tiers. An n-tier application can provide separate layers for each of the following services - Presentation Layer, Dynamic Presentation, Business logic, and Data base access. A browser takes care of the presentation layer, and JSP / Servlet / XML / SOAP and XSL take care of the dynamic presentation, Session EJB takes care of the business logic and Entity beans take care of the data access using JDBC. The layered approach allows each layer to focus on a specific role -- for example, allowing a Web server to serve Web-pages, an application server to serve applications, and a database server to serve databases. With the benefit of an n-tier architecture and ASI’s strong expertise on the J2EE framework the team at ASI can deliver unprecedented levels of value to customers. Contact ASI to learn how ASI can help your businesses to do better.