It is imperative that all your Java applications (packages)
be stored in separate directories). I recommend that you keep all your
Java files below the C:\cis206
directory (you may wish to substitute
C for other drive). To create this directory, do this:
Select the drive's root
directory (C:).
Next, click File, New (
),
Folder (
) options.
...
Type cis206
and press 
.
You will next create another folder (test)
inside the cis206
folder. Do this:
Select the the
cis206
folder.
Right-click the folder's
contents.
From the pop-up menu, select
option New.
Finally, select option Folder.
...
Type
test and
press .
Double-click the folder
to get in.
...
You will now develop a Java program (SumOf.java)
using a text editor. Make sure that your C:\cis206\test
folder is open and do this:
Right-click the folder's
contents.
From the pop-up menu, select
option New.
Finally, select option Text
Document.
Right away type SumOf.java
over the default name and press .
Click Yes to confirm your action.
Now, open the new file in a
text editor (Notepad or EditPad)**.
Right-click the file.
Select Send
To.
Select
EditPad Lite (or other text editor)***.
Type the following Java program (another text editor can be used):
Save the program ()
and open the Command (DOS-Prompt) window
(). If you do not have a
shortcut to the Commander in your Quick
menu, execute this: Start > Run > command
.
Try the following commands:
Change the working directory
to C:\cis206\test: cd
\cis206\test
Compile your program: javac
-classpath . SumOf.java
[If you get compilation error messages, go back
to your editor, find the source of the error and fix it.]
Run the program to calculate
the sum of 1 and 2: java
-cp . SumOf 1 2
Run the program to calculate
the sum of 4.75 and 7.25: Java
-cp . SumOf 4.75 7.25
Try an incomplete sum: Java
-cp . SumOf 10
[Java expects two argument. If you supply only one
argument the array arg (see code) will contain
one entry (at index 0). An attempt to access
the second one (at index 1) will fail, since
there is no such entry. Thus ArrayIndexOutOfBoundsException!
This is an example for a run-time error.]
Try a sum of more than two
numbers: Java
-cp . SumOf 10 20 30
[The sum of only two first is returned. The third
one is ignored, since the program only takes the first two! This is an
example for a logical error. The program has not crashed but it failed
to return a correct output.]
Type exit
and press to close the
Command widow.
In your next exercise, you will create batch files to simplify compilation and execution of your program. A batch file is a text file that may contain commands and control statements. It can be thought of as a shortcut. In Windows, batch files have the .bat extension.
Switch back to Windows Explorer and create another text document.
...
12
Type comp.bat, press ,
and click Yes.
Right-click the batch file ()
and go for Edit ().
The the command to compile your program:
Save the file:
You will now recycle this file to create another batch file (exec.bat). Modify the command so that it will look like the following one. Note that %1 and %2 represent arguments that will be supplied at the command line.
Invoke the File > Save As command (not File > Save):
Change the name of the file to exec.bat and click Save.
Close the editor.
Open the Command window again.
Perform the following commands:
CD \cis206\test
comp
exec 1 2
Here is how it works with the exec.bat
command. The exec 10 20 command invokes
the exec.bat command, replacing the argument
%1 with a value of 10
and the argument %2 with a value of 20.,
thus creating command:
Java -classpath .
Sum of 10 20
that is carried out.
Type exit and press
to close the Command widow.
