UPLOADING APPOINTMENTS AND CONTACTS DETAILED DESIGN” The case study architectural team has now completed the architecture for querying appointments and contacts. They now consider the architecture needed to allow the customers to upload their appointments and contacts from the existing Visual Basic application to the database on the server.
Having the existing Visual Basic application communicate directly to the database could decrease the security of the system. It could also decrease adaptability because changing the database logic would then require distributing a new version of the client application to the users. Instead, the project designers decide to have the Visual Basic application trigger a Java servlet that will insert the data in the database.
MICROSOFT VISUAL BASIC:-
You may wonder how Microsoft Visual Basic can talk to a Java servlet. This is actually no problem; any kind of system that can generate an HTTP request can talk to a servlet. Visual Basic, like most programming environments, is perfectly capable of generating an HTTP request to communicate to a Java servlet.
The designers could have the Visual Basic application communicate with one of the controller servlets in the current architecture, but they decide it would be more cohesive to create a new servlet for this purpose.
This servlet will not use any JSP pages because it will not be returning any HTML or other Web content to the Visual Basic client.
THE VISUAL BASIC CLIENT SENDS:-
The Visual Basic client sends all the appointment and contact data to the Java servlet, the servlet saves the data to the database, and it returns back to the Visual Basic application the number of records saved. This is shown in the UML Deployment diagram in Figure 29-4.
The design team then considers what format to send the data in. They want a clear, verifiable, adaptable format. Because XML meets all these requirements and is an excellent way to send data between systems, they decide to send the appointment and contact data in an XML format.
The design team has now completed the high-level architectural design of the system. They have chosen the technologies that they will be using and the organization of those technologies required to solve the business problem.
In the detailed design, they will specify how each individual part of the system will be implemented. The Component and Deployment diagrams illustrate how different Web technologies will be organized.
In the detailed design, the component and deployment diagrams will be used less and the Class, Object, Sequence, and Collaboration diagrams will tend to be used more.
QUERYING APPOINTMENTS AND CONTACTS:-
In the detailed design phase, the designers want to create a roadmap for the programmers, specifying how the browsers, servlets, JSP pages, JavaBeans, and databases will work together to allow customers to query for appointments and contacts.
Because there isn’t space or time to explore the entire detailed design, we will focus on the design of appointment querying by customers using traditional wired Web clients.