An Active Class indicates that, when instantiated, the Class controls its own execution. Rather than being invoked or activated by other objects, it can operate standalone and define its own thread of behavior.
To define an Active Class in Enterprise Architect, follow the steps below:
- Highlight a Class, and display its Properties dialog.
- Click on the Advanced button.
- Select the Is Active checkbox.
- Click on the OK button to save the details.
OMG UML Specification
The OMG UML specification (UML Superstructure Specification, v2.1.1, p. 438) states:
An active object is an object that, as a direct consequence of its creation, commences to execute its classifier behavior, and does not cease until either the complete behavior is executed or the object is terminated by some external object. (This is sometimes referred to as "the object having its own thread of control.") The points at which an active object responds to communications from other objects is determined solely by the behavior of the active object and not by the invoking object. If the classifier behavior of an active object completes, the object is terminated.