Figure 2

DraGnET software architecture. The DraGnET web application uses Struts to implement the Model-View-Controller (MVC) architecture. The view represents the presentation of the application and is implemented through Java Server Pages (JSP). The Controller is responsible for intercepting and translating user input into actions to be performed by the Model. The Controller receives the request from the browser, invokes a business operation and coordinates the view to be returned to the browser. The Struts Action servlet populates information from the JSP to the appropriate Struts Action Form then throws control to the Struts Action. The Struts Action gets data from the appropriate Struts Action Form and sends the information to the Model where certain actions like retrievals and updates will be performed. The Model is where communication with the database takes place through Hibernate. Hibernate is used to map Model Classes (Java objects) to tables in the database. Model Classes are also used to execute BLAST functionalities provided through the application's web interface. The Model represents enterprise data and the business rules that govern access to and updates of this data.