System Architecture

On the third level, there is the work station (Client), which relies on a Browser as the executive program environment. All standard, most popular browsers are supported. Acrobat Reader is used for reports presentations.

Windows-like GUI (Graphical User Interface) is implemented using HTML and JavaScript.

The second level is the applicative Web Server. The program uses the Tomcat Application Server, Apache Web Server, and Jasper Reports.

The first level is the DB Server. The main product that is being used is Oracle RDBMS.

The business logic is partly implemented with PL / SQL procedures, and mostly through mid-level (LEVEL II) Java classes. For the development of procedures, procedural language adequate to the database server is used (Oracle PL/SQL).

Products developed using three-tier architecture: asw:dominus, asw:credis, asw:temporis, asw:libris, asw:utilitas, asw:examinus.

Basic advantages of the three-tier architecture:

• Web access – allowing operation from distant locations
• Administration reduction on the works stations due to browser installation
• It is simple and efficiently maintained
• The system is scalable, so it’s quickly adapted to complex organizational and locational structures.
  

GUI is created by using Java Swing. JDBC driver is utilized to interact with the database. Java Web Start technology is used for code distribution. Program code is installed on the server and work station accepts the updated copy of code into its local cash when starting the application.

There is DB server, usually Oracle RDBMS and PostgreSQL

Business logic is implemented in PL/pgSQL or PL/SQL procedures, as well as in Java programming language..

Two-tier architecture is used in the creation of the following products:
ITCC, LPH, and asw:mercantis.

Main benefits of two-layer architecture:

• Simple and safe solution adjusted to various needs
• Scalability
• Support for special POS devices management (Java POS standards)