Question

I’m drawing a UML Sequence Diagram for a writeToFile() method. In the method, the following calls are made:

• System.out.println()
• System.err.println()
• System.exit();

I’m confused about how to represent this in the diagram. Do I draw three seperate rectangles: System.out, System.err and System respectively?

Thanks for your help.

Answer 1

You might want to use three lifelines:

1. System.out
2. System.err
3. System

And then show the three calls

1. println (message to System.out instance)
2. println (message to System.err instance)
3. exit (message to System instance)