ArgoUML datatypes, classes and interfaces are effectively organized as a hierarchy beneath the overall model itself. They are grouped in four packages, lang, math, net and util, themselves subpackages of java, which is a subpackage of the model itself. Figure 24.1, “Hierarchy of datatypes, classes and interfaces within ArgoUML” shows this structure.

Figure 24.1. Hierarchy of datatypes, classes and interfaces within ArgoUML

You will not find build-in DataTypes, Classes, and Interfaces exposed within the model by default (i.e. they are not present in the explorer). However, once you select one of the built-in DataTypes, Classes, or Interfaces (in the "Type" combo-box on the property sheet of a parameter of an operation of a class), then it becomes visible: you will find that the DataType, Class, or Interface has appeared in the model, in its correct package stucture for the latter 2.