1. HW 1
Kirk Scott

3. Remember, the ultimate authority for what this assignment consists of for any given semester is the Word document posted on the course Web site
In general the assignment covers:
toString(), equals(), clone()
Singleton
Prototype
Builder
Proxy

4. The contents of the Word document (at some point in time) are given on the following overheads
The is just for use as an in-class reference
It is representative of the assignment and illustrates in general the kind of requirements and check-offs there are for the homework

5. CSCE 302, HW 1
Explanation and Check-Off
Name: _________________________________

6. Preliminary explanation of the assignment:
The first three parts of this assignment allow a lot of latitude in how you do them.
The fourth and fifth parts are set up in a more structured way.
Whether for relatively structured or relatively unstructured parts, the general purpose of the assignment can be described in this way:

7. A. You need to sort through the material, the design patterns, until you’ve got a clear mental picture of what they are.
B. You need to make up your own examples or follow the specifications given and do the implementation.
C. When turning in your assignment you need to demonstrate your examples to me, explaining how they correctly reflect the pattern, characteristics, or specifications that they’re supposed to represent.

8. When you hand in your homework, it is reasonable to expect that you will show me code, run the code, show the results, and use both the source and the outcome to explain what you accomplished.
I will not collect anything from you.
Evaluation will be done on this check-off sheet in real time.

9. In other situations I am known to simply do black box testing.
But in this case, if it’s helpful to show code, then plan on showing it.
It’s your call on what you show and how you explain it.

10. In some courses you are expected to do a formal presentation or write a paper explaining some development work you’ve done.
In this course, in addition to writing the code itself, you’re expected to practice the skill of describing what you’ve done on a one-on-one, piece-by-piece basis, with someone who is knowledgeable about what the code was supposed to do.

11. In other words, the motivation behind the assignment is both to do some development work and also to get experience in expository presentation by talking to an individual rather than doing a PowerPoint presentation to a group.
The individual parts of the assignment are given below.

12. 1. ______ 10 pts. toString(), equals(), clone():
Write the code for two classes.
You may name these classes whatever you want to and you may include in them whatever you want to.
These two classes should be in a superclass-subclass relationship.
For each of the classes, implement toString(), equals(), and clone() methods.
Write a test program which will confirm that each of these three methods works for each of the two classes.

13. 2. ______ 10 pts. Singleton:
Use either of the two classes you made for part 1, copy it, and modify it so that it is a Singleton class.
Write a test program which demonstrates that you can construct one instance of the class.
The test program should also demonstrate that it’s not possible to successfully construct another instance of the class.

14. 3. ______ 10 pts. Prototype:
Once again, this is pretty free-form.
Choose one of the classes you made above.
Write a prototype(), or partialCopy() method for it.
It’s your choice which instance variable values are default and which are taken from the implicit parameter.
Write a test program that demonstrates the use and outcome of using the method.

15. 4. ______ 10 pts. Builder:
This part comes with detailed instructions.
It is too much of a mess to have you make up your own example.
The goal of this part of the assignment is to get rid of the distractions of parsing and everything else extraneous to the basic pattern.
By getting rid of everything extraneous, no actual reason remains which would cause you want or need to do building.

16. But the basics of the pattern will be illustrated.
Your goal is to follow the specifications to a T and include the testing elements so that it’s straightforward to show that the pattern was implemented.
You may refer to the UML diagrams on overheads number 70 and 71 to see an illustration of the very basic version of the pattern which the specifications ask for.

17. I. Let there be a base class named MyBaseClass
I. Let there be a base class named MyBaseClass. Let it be a normal, concrete class with these characteristics:
A. It has three integer instance variables simply named baseA, baseB, and baseC.
B. It has a constructor which takes input parameters for each of the instance variables.
C. It has get and set methods for each of the instance variables.
D. It has a toString() method.

18. II. Let there be a builder class named MyBuilderClass
II. Let there be a builder class named MyBuilderClass. Let it be a normal, concrete class with these characteristics:
A. Like MyBaseClass, it has three integer variables. For clarity’s sake, let them be named builderA, builderB, and builder.
B. It has a default constructor which initializes the three instance variables to zero.
C. It has set methods for the three instance variables. (Get methods are not necessary.)

19. D. It has a build() method with these characteristics:
The method tests to see if these conditions are true:
builderA >= 1
builderB >= 10
builderC >= 100
If all these conditions hold true, the method calls the MyBaseClass constructor with the builder variables as construction parameters and returns the MyBaseClass object which is constructed.
If any of the conditions doesn’t hold true, the method constructs and throws an instance of the MyBuilderException class (see below).

20. III. Let there be a class named MyBuilderException with these characteristics:
A. It extends the system supplied Exception class.
B. It has a default constructor consistent with its superclass so that in your code it’s possible to construct an instance of it.

21. IV. Let there be a test program named MyBuilderTest with these characteristics:
A. It constructs a MyBuilderClass object.
B. It calls the set method for the variables on the builder, passing in values that would be valid for a MyBaseClass object.
C. In a try/catch block, it calls the build() method on the builder.
D. It prints out the result of calling the toString() method on the MyBaseClass object that’s returned.

22. E. It creates another MyBuilderClass object.
F. It calls the set methods on the builder object, passing in at least one parameter value which is out of range.
G. In a try/catch block, it calls the build() method on this builder object.
H. It should catch the exception and all that the catch block needs to contain is a line of code which causes a message to printed out announcing that building has failed.

23. 5. ______ 10 pts. Proxy: Like Builder, this part comes with detailed instructions.
It is also too much of a mess to have you make up your own example.
Because the book example is relatively complex by itself, and also because the example involves Threads and Swing, it is not easy to come up with logical specification which will allow you to design a homework solution without a lot of guidance.

24. You may certainly refer to the overheads that cover Threads and Swing, plus the overheads which cover the Proxy design pattern when trying to figure out how to do this part of the assignment.
In general though, whether the overall purpose is very clear, you should try to follow the specific instructions given below.
For better or worse, because of the nature of the problem, the approach is pretty much to lead you by the nose and hope that the end result is functional.

25. I. Let there be a base class named TestProxy
I. Let there be a base class named TestProxy. Let it be a normal, concrete class with a main() method. Inside the main() method, you should do the following:
A. Construct an instance of JFrame.
B. Construct an instance of MyEditorPaneProxy (see below) with two construction parameters, a String containing this URL, “ and a reference to the frame.

26. C. Add the pane proxy object to a JScrollPane object and add this to the frame.
D. Set the frame size to something suitable and set the frame to be visible.
E. For the purposes of effective testing, insert a Thread.sleep() call into your code.
F. Call the load() method (see below) on the pane proxy object.

27. II. Let there be a proxy class named MyEditorPaneProxy
II. Let there be a proxy class named MyEditorPaneProxy. Let it be a normal, concrete class with these characteristics:
A. It extends JEditorPane.
B. It implements Runnable.

28. C. It has two instance variables, String URLPath and JFrame myFrameReference.
It has a constructor with these characteristics:
It takes parameters for the two instance variables.
It sets the values of the parameters.
It then sets its page to “
It then repaints the frame.

29. D. The class has a load() method with these characteristics:
It sets the page to “
It then repaints the frame.
It includes a time delay.
It then creates a thread based on the pane and calls start() on it.

30. E. The class has a run() method with these characteristics:
It sets the page to the URLPath value that was passed in when the pane object was constructed.
It then repaints the frame.

31. Black box testing and observable results:
If you get the mess above to work, what will it do; what will you see?
First it should bring up the Yahoo Web page.
This is the equivalent of “Absent” in the book.
Next it should bring up the UAA Web page.
This is the equivalent of “Loading” in the book.
Finally, it should bring up the Payap University Web page.

32. Remember, the JEditorPane displays Web pages poorly, so the contents may not be recognizable.
But it should be recognizable that different things are being shown in sequence.
Also remember that you will probably need to put in calls to sleep() so that your life doesn’t flash before your eyes too quickly to see it.

33. A successful implementation will make it clear that you’re sequencing through three different Web pages, even if the display of the Web pages is so poor that you can’t tell exactly what they are.
If the delays are long enough, there might be time to use the scroll bars to look at some content and verify which page you’re looking at at any given time.

34. The End