Mobinor itself is focusing on robust, modular technologies. Whatever size of the application, technological choises are important. There is no right tecnologies, but there is a difference between good and bad technologies. Mobinor has selected a layered approach, with the following technologies:

DATA LAYER

At the data layer, Mobinor is using different storage and directory technologies:

• SQL databases
• LDAP catalog server
• Files

Mobinor is mainly using the MySQL database server. MySQL is popular, open source, relational database, which supports most common sql features. Sql is the dominating standard for databases, and with well written java applications, the choice of database does not matter much. With container based J2EE entity beans, you rarely program any code directly towards the database.

For storage of catalog data, Mobinor uses OpenLDAP, an open source directory server for Unix based operational systems. OpenLDAP follows the LDAP standard, and can communicate with clients implementing the LDAP standard. LDAP is the leading standard for LDAP directories. Netscape has been one of the leading organizations developing LDAP solutions, and LDAP has broad support from the internet world, and is also widely in use for intranet use. LDAP is very well suited for information regarding organisations, peple, network equipment and other information well suited for directories. One of the key benefits of LDAP is fast lookup, much faster than for sql databases. But nothing is for free, and this is also the case for LDAP servers. The cost of getting fast lookup, is slow update. Thus LDAP is well suited for data that is use often, but rearly updated. Authentication is one example of such a service, well suited for LDAP. 

For some cases information is stored in files. Some examples of this can be configurationfiles for some programs, documents etc. And of cours web pages, if they are not stored in a database based publishing system.

BUSINESS LOGIC

Many developers do not split business and presentation logic. This is often the case for some web driven services, where html for presentation and scripting business logic is combined in web pages. Mobinor use ejb application servers, and most business logic is run on these servers. EJB has the following main components:

• Entity beans
• Session beans
• Message beans

Entity beans are dataobjects, mapping data stored in databases. Bu using container managed entity beans, there is almost no need to write sql code to access data in the database. This is hanlded by the application serer and the database. But if you wish to have tighter control of database communcation, you can write sql commans, either complete by writing bean managed entity beans, or to improve some queries.

Session contain business logic. By implementing the business logic on an application server, the presentation level can be kept completely clean of business logic. This way more than one client can connect to the business logic. 

The last type is message beans. This is quite new i ejb. By introducing message beans, the application server can handle queues. If there is a need to send messages between asynchronous systems, message beans will be a good mechanism. Clients can then put messages in the queue for a message been, and then continue doing something else, while the message bean will process all the messages. Message beans can also handle situations where communcation with other asynchronous systems are not available.

Mobinor uses JBoss, and open source application server, as its application server.

PRESENTATION LAYER

At the presentation layer, Mobinor uses java servlets and java server pages for web sites. Mobinor uses Apache web server for static files, and Tomcat for java server pages and java servlets.

With these technologies, there can be dynamic intefaces. But there are still some issues to be resolved. By usint scripting directly, the code might be hard to maintain. To be able to create clean frontend code, Mobinor has selected Struts. Struts is a MVC framework (Model View Controller). Struts makes it possible to have full control, even for large systems.

For wireless user interfaces, J2ME is the natural choice.

OPERATING SYSTEMS

All technologies above are based on open standards, and run on most plattforms. Mobinor has selected Linux as a plattform for it's own services. But because all applications are based on open standards, it is easy to move to other platforms. The reason for using Linux, is the good price/performance ratio.

MODELLING

To keep control of each system from its early age until it's funeral, Mobinor is using Unified Modelling Language (UML). UML is a good modelling concept giving a practical tool for modelling. Mobinor is using Enterprise Architect from Sparx system, this tool gives good value for money.