Java Reference
In-Depth Information
This type of diagram has many limits (for example, it assumes that services are contained in a
hierarchical fashion, it is not always true, it is highly imprecise, and so on). It was designed
mainly to better introduce and discuss some common situations. Nevertheless, it can be
adapted to a great variety of real cases (modifying the values used on the axis) and purposes
(as we will see in some examples in the next section).
Another important aspect is the
cost
associated with the points (that are deployment circuits
instances) on the diagram. Cost is a generic term, used here to indicate various parameters
such as license fees (JNLP is free, but another third-party technology may not be), the com-
plexity posed to the end-user, or other parameters. It depends on the situation and the current
economic constraints. Costs are intuitively progressing from bottom-left (simpler means for
simpler deployment services, so cheaper) to top-right (more powerful circuits, so more expen-
sive).
In the following section, we will see some uses of the proposed diagram.
Sets of Deployment Circuits
We said that each point in a deployment design diagram represents a particular deployment cir-
cuit. Hence, sets of such points represent a collection of deployment circuits, such as area A in
Figure 4.2.
The area B indicates the set of all the possible deployment circuits that can be implemented
using the standard JNLP 1.0 technology; that is, customizing the technology without adding
further services by means of some proprietary code that takes advantage of some JNLP
features.
N
OTE
4
As we will see, it is a common practice to extend deployment means with specifically
developed code in order to implement more easily a given set of deployment services,
as discussed following.
We will examine plenty of such areas in the following section.
Showing the Limits of Each Deployment Technology
Figure 4.3 illustrates a possible use of the Deployment Design Box. A point on the diagram in
Figure 4.3 represents a deployment circuit described by the employed Java technologies (hori-
zontally) and the given deployment services provided (vertical axis). The dotted curve
describes the level of services available when employing a given Java technology (the “means”
horizontal axis).