Information Technology Reference
In-Depth Information
• A Set class inherits from a BinaryTree class
• A Set class inherits from a Bag class
• A Player class inherits from a User class
• A Window class inherits from a Polygon class
4. Consider Polyline, Polygon, and Point classes Write the following constraints
in OCL:
• A polygon is composed of a sequence of at least three points
• A polygon is composed of a sequence of points starting and ending at the
same point
• The points returned by the getpoints (bbox) method of a polygon are within
the bbox rectangle
5. Why is maintaining consistency between the analysis model and the object
model difficult? Illustrate your point with a change to the object design model.
6. Group Diary
A group diary and time management system is intended to support the timet-
abling of meetings and appointments across a group of co-workers. When an
appointment is to be made that involves a number of people, the system finds a
common slot in each of their diaries and arranges the appointment for that time.
If no common slots are available, it interacts with the user to rearrange his or her
personal diary to make room for the appointment.
• For the bored: Announce successful meetings per email. Permit people to
block out personal time. Set up provisional meetings that must be con-
firmed by all participants before they are finalized.
• Identify possible objects in your system and develop an object-oriented
design for it. You may make any reasonable assumptions about the systems
when deriving the design.
• Draw a sequence diagram showing the interactions of objects in your
system.
• Draw a state chart showing the possible state changes in one or more of the
objects defined.
• Write a precise interface in Java of the objects you have defined.
7. Define: (a) precondition; (b) postcondition; (c) assertion; (d) invariance con-
dition; (e) Types; (f) signature
8. How do you decide whether something is to be modeled as an attribute or a
class?
9. Define the terms: pattern, design pattern, analysis pattern, and organizational
pattern architectural pattern. Give examples of each.
10. Produce a framework template for school timetable preparation: allocating
suitable classrooms, qualified teachers, ten subjects, and five one-hour time-
slots per weekday. Include all invariants; e.g. Chemistry needs a classroom
with sinks and there must be at least five hours of Math and English per week.
