How simple can it be to specify a data maintenance application?
simpleApp.mdl Rational Rose file
simple.vsd Microsoft Visio file
simple.zip 100% generated.
See It Running
This is an entire 3-tier application, built from a very simple input. It consists of
one class which has a single attribute on it. The first thing to notice is that there
is no application definition or jar descriptions or anything else technical. There are
certainly no J2EE specific devices such as remote interfaces!
If a class is shown on the diagram, it is assumed to be a persistent aggregation of data,
which we refer to as an entity. That means the information will be available for different
users of the system, or at a later date, and typically this achieved by attaching to a
database. An entity will be turned into an entity-EJB in j2ee, and a whole lot more.
As well as the EJB and its interfaces; delegates, delegate-factories, data manipulation
constructs, session EJBs and maintenance pages will all be generated automatically.
But this is not a concern for the modeller. The modeller simply needs to specify the entity.
Notice that in this case the attribute has a name of "name", but no type and no classification.
By default, an attribute on an entity will be simple text, to appear on maintenance pages in
a simple textbox. Again, there are no get or set methods to worry about. This should be
thought of as a logical model.
Of course there are a host of flags and settings available to change the default
behaviour and these are exploited in later sample applications.