Programming Assignment 1 Solution

If you want to do all your lab work on your own PC or Mac, download
Box Sync and Eclipse (steps 12 and 14) before lab on Wednesday so we
don't overload the WiFi.  You will do steps 13 and 15 during lab.

If you want to use the lab computer for this lab, please pay attention
to the instructions given for steps 13 and 15 so you will know how to
do them at home later.

PAY ATTENTION to steps 6-9.  Read the notes "Object Oriented Programming"
on the CSC220 Lecture Discussion Forum this evening.  There will be
questions about it on the quiz Thursday.

1. Accounts
    log in
        change password:
               Applications->System Tools->Terminal
           yppasswd
        log out and log in again

   If you are working on your PC or MAC
    log out
    start your favorite browser on your PC or MAC

   If you are working on the lab computer
        start Firefox (Applications->Internet->Firefox)

   go into Blackboard for the lecture (miami.edu/blackboard)
   discussion board (on the left)
   CSC220 Lecture Discussion Board
   SUBSCRIBE
   go to the lab posting
   go to source directory

2. Create a new Java project
    start eclipse

        right-click on background to start terminal
                type eclipse and hit return
                OR
                Start Eclipse on your PC or Mac.

    accept default location for workspace
        select workbench (if it gives you a choice)
        Create a new Java Project named csc220

        Click the little downarrow next to the tiny + on the
        upper left
                OR
        File->New Project->Java->Java Project

        Next
        project name: csc220
        Finish
                Don't Create module-info.java (if it asks)
        Yes to Java Perspective (if it asks)

   If you are working on your own PC or MAC
    shut down Eclipse   
    do steps 13 and 15 now.
        restart Eclipse

3. Create a new package for this lab
    expand csc220 (on the left)
    right click on src
        new -> package
        name it prog01 (NOT Prog01 NOT prog 01 NO CAPITALS OR SPACES)
    Finish

4. Create java files in this package
    visit the source directory (on the discussion board)
        visit Main.java
        save into workspace/csc220/src/prog01
        do the same for Computer.java and Laptop.java
        click on prog01 in Eclipse and press f5
        or right-click and select REFRESH

5. Fix compiler errors and run
    open prog01
        double-click on Main.java
        comment out offending lines
        press white triangle inside green circle to run
    Go to line with runtime error by double clicking on it
    something like (Main.java:21)
        comment out line with run time error and try again

6. Debugging
    set a breakpoint on the first line "Set a breakpoint here..."
    (right click to the left of line and select Toggle Breakpoint)
        run the debugger (buggy icon next to white triangle)
    let it switch you to debug perspective
        single step through the program
    use step-into (two symbols to the right of red square near top)
        if you get a blank screen too many times, use step-return
        if you are not calling methods in the package, use step-over
        notice how you can see the value of variables
        notice how you can see where you called from
    try changing the value of a variable, like procSpeed in Computer
    to access object variables, expand "this"
        try setting breakpoints in methods

7. Use the Visual Debugger
    It's already installed in the lab.
    To install on your PC or Mac:
    Open Eclipse and go to Help->Install New Software...
    Click Add.. and use location
            http://web.cs.miami.edu/home/jgmaster/DebugPlugin/
        Hit Add.
    Uncheck "Group Items by Category" on this form
        Check CSC220 Debugging Visualizer
    Click "next" and "accept" until it starts to install

    To Use:
    Put a breakpoint in whatever file you're going to debug
    Go to Window->Show View->Other...
    Expand the Debug category and select "CSC220 Debugging Visualizer"
    The view should appear in the panel near the console view,
        You can move this around and even move it out by just dragging the tab.
    Start debugging the program with the bug button
    When the program breaks on a breakpoint, 
        the visualizer should show the current state
        of the data structure and all other local variables. 
    Single step (over or into) and the visualization should update.
    Try looking at the Variables view and try to see the correspondences
        from the textual layout of the data to the visual layout

    Double click a node with a highlighted border to expand it
    Drag the nodes in between single stepping:
        they should remain in place during the next step.
    Right click and click save in the context menu
        to save an image of the figure

8. Object Oriented Programming
    notice that c2 is an instance of a Laptop
    even though the variable is of type Computer

Even if we call your laptop a computer, it's still a laptop.
For example, I say:  ``Please install Eclipse on your computer.''
That might refer to your laptop or your desktop.

        notice that when you print out c2,
        it calls the Laptop toString method
    you can set a breakpoint in that toString method

9. Overriding a method
    uncomment the computePower method in Laptop.java
    fix the first compiler error by using getRamSize()
    fix the second error by changing processorSpeed
    from private to protected in Computer.java
        **notice that c2.computePower() now calls this method**


DIAGNOSTIC EXERCISE

10. Put Lamb.java in place and run it.  You need to right click on it
    and run it as an application.  Ask for help if you can't get it
    running.  It will run but print incorrect output:

Mary had a little lamb 
Mary had a little lamb 
Mary had a little lamb 
Mary had a little lamb 
Mary had a little lamb 
Mary had a little lamb 
Final sentence should be:
Doctor Mary only had eaten a very little lamb chop

11. Implement the insert method.  Your final output should be:

Mary had a little lamb 
Mary had a very little lamb 
Mary only had a very little lamb 
Doctor Mary only had a very little lamb 
Doctor Mary only had a very little lamb chop 
Doctor Mary only had eaten a very little lamb chop 
Final sentence should be:
Doctor Mary only had eaten a very little lamb chop

    This is a diagnostic exercise.  Feel free to ask the assistants
    for help using the debugger, but do not ask them or your fellow
    classmates for hints about the correct logic or why your program
    isn't working.

    Show your working program to an assistant and tell them your login
    id (????220) if you can get it working before the end of lab period.


HOMEWORK ON YOUR PC or MAC

12. Log into box.miami.edu.  This is a free web storage provided to UM
    students.

    Click on your name or initials on the upper and select apps.
    Select Windows or Mac.  Download and install Box Sync.

    Run Box Sync and set up your CaneLink credentials.

    This process should have created a folder named Box Sync on your computer.

13. ON YOUR COMPUTER using File Explorer or Finder
    (NOT ON THE WEB in box.miami.edu)
    create a folder inside your Box Sync folder with the same name as
    the login you are given in lab on Wednesday.  It is four of your
    initials followed by 220, like vjmi220 for Victor Milenkovic.

    NOW go back to the main page of box.miami.edu and verify that the
    folder has (magically) appeared there.

    Right-click on your folder on box.miami.edu.
    Share --> Invite Collaborators.
    Invite vjm@cs.miami.edu using the default setting
    (making me an Editor).

14. Install Eclipse: go to eclipse.org/downloads and click Download 64-bit.
    Windows users may also have to install the JDK.  Try the x64 version first.

    Run Eclipse and take note of where it puts your "workspace".
    Go to the workbench and create a new Java project named csc220.
    See step 2 above.

    Shut down Eclipse.
    
15. Go to the eclipse-workspace/csc220 folder in the file explorer or
    finder and delete src.

    Replace it with a link from the folder you created in Box Sync:

    On a PC

       Click start, type "command prompt" in the run window, and hit return.
       Adapt the following command to your circumstances:

mklink /d c:\Users\Victor\workspace\csc220\src c:\Users\Victor\"Box Sync"\vjmi220
    On a Mac

       spotlight (cmnd-space or click the magnifying glass).
       Search for "terminal" and hit return.
       Adapt the following command to your circumstances:

ln -s /Users/vjm/"Box Sync"/vjmi220 /Users/vjm/eclipse-workspace/csc220/src

16. Do steps 4-9 above on your PC or Mac.  When you are done, go to
    box.miami.edu.  In your folder you should see Computer.java etc
    plus an images folder containing images of your debugging with the
    Visual Debugger.  If you reply to the prog01 posting with a
    request for help.