Download CS 201, Getting Started in the Lab

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CS 201, Getting Started in the Lab
Compiling, running, getting files, printing source code and output:
1. We will be using TextPad as our editor and programming environment for Java. You can
find the TextPad application on the lab machines by going through Start, Programs.
2. Under Tools in the TextPad menu you will find 3 options related to java: Compile Java,
Run Java Application, and Run Java Applet. For the time being our primary concern is
compiling and running applications. Applets come later.
3. Under Tools in the TextPad menu you will also see a plain “Run…” option. This is
mentioned only because you will probably mistakenly try to use this once. Using this option
to try and run a Java program will either bring up a dialog box asking what application to
run, or a mystery error message. You need to make sure you’re trying to run your programs
with the Run Java Application option.
4. The documentation for Java is not available through TextPad. On the class Web page there
is a link to the Java API Documentation, which is located on the Sun web site. You might
want to add this to your favorites list so that you can have it handy in your Web browser
while you’re working on programming.
5. As noted on the Web page for the class, downloading program files provided by me isn’t
very convenient. This is what you have to do: Open the Web page containing the Java code,
edit/select all, edit/copy, then open TextPad, file/new, edit/paste. Then save the new file with
the same name as the name of the class contained in it, capitalized in exactly the same way,
and with the .java extension.
6. As a test of compiling and running a program, download the file Firstprog.java from my Web
page and save it in the temp directory of the c: drive of the machine you’re working on. You
may also try working off of a diskette or through a Web drive, but in any case it should work
if you’ve saved the file in the temp directory.
7. Using TextPad, open the file Firstprog.java. Then click the Compile Java menu item. This
will take several seconds. A successful compilation will simply end showing the program
file on the screen. An unsuccessful compilation shows a new screen with the error messages
for the compilation. This sample program contains no errors as given. If you get compiler
errors, check to make sure you have correctly saved the file under the name of the class
contained within it and with the .java extension, and then try compiling again.
8. After a successful compilation you can then take the Run Java Application option in the
menu. This should bring up a DOS Window with the program output in it.
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9. You can print program source files directly out of TextPad through the File option in the
menu. The name of the printer in the lab is PRINTSRV/lpwin. If it hasn’t been already, it
needs to be installed through Windows under your login in order to show up as an option
when printing.
10. Depending on the version of Windows you have, you may be able to print output in more
than one way. In any case you can print it as follows: Output will be contained in a DOS
Window. Make sure that window is active by clicking on it. Press the 2 keys ALT+PRINT
SCREEN to capture a copy of the window; then open MS Word, and do edit/paste into a new
Word document. A copy of the whole DOS Window will appear in the document. You can
make its contents black on white instead of white on black by using the mouse to highlight
the DOS screen before capturing the copy if you want to.
Java file naming, capitalization, and extensions:
1. Java program files have the extension .java.
2. The name of the file you save a program in (except for the extension) has to agree exactly
(including capitalization) with the class name given at the top of the program (public class
Program-name).
3. Java is case sensitive and java program files have to start with a capital letter. DOS and
Windows don't make strong case distinctions, but the compiler will give errors unless the
program file starts with a capital letter.
Handing in and saving assignments:
1. Hand in printed copies of the program files you wrote plus printed copies of their output.
Remember to save copies of the files on a diskette or somewhere else for future reference.
Some programming assignments are cumulative.
2. When you hand in printed material you need to include at the top of each page the lab
number, the program name (both for the source and the output), and your name. Feel free to
hand write this information on the pages. If there is more than one page to the assignment
you should staple or clip the pages together, in order, so that I don’t misplace them.
3. There may be problems with compiling and running files off of diskettes. In order to
compile and run, you may have to save the source file in a folder on the hard drive, say
c:\temp. If you do so, remember to also save a copy on your diskette to take with you when
you go.