UML习题解答完整.pdfVIP

UML图习题解答 类图和对象图 1. On a single diagram, illustrate the following using the UML notation for objects, links and messages. a) An object of class Window, with no attributes shown. (b) An object of class Rectangle with attributes length and width. Assume that the rectangle class supports an operation to return the area of a rectangle object. (c) A link between the window and rectangle objects, modeling the fact that the rectangle defines the screen coordinates of the window. (d) The window object sending a message to the rectangle asking for its area. Draw a class diagram showing Window and Rectangle classes with the properties mentioned in this question. 龚晓庆 2 The objects, links and messages required are shown in the diagram below. The Window and Rectangle classes are documented in the following class diagram. 龚晓庆 3 2. Suppose that an environmental monitoring station contains three sensors, namely a thermometer, a rain gauge and a humidity reader. In addition, there is an output device, known as a printer, on which the readings from these three sensors are shown. Readings are taken and transcribed onto the printer every five minutes. This process is known as ‘taking a checkpoint’. (a) Draw an object diagram showing a plausible configuration for these objects, and include on the diagram the messages that might be generated in the system every time a checkpoint is taken. Assume that a checkpoint is initiated by a message sent from a timer object to the monitoring station. (b) Does your diagram clearly show the order in which messages are sent? If not, how might this be shown? (c) Draw a class diagram summarizing the structure of the monitoring station. 龚晓庆 4 A possible object diagram is shown below. The three sensors are shown as belonging to different cla