An Alternative Way to Run JES


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An Alternative Way to Run JES

Here's an alternative way to run JES. This way gets around the conflict with the Java files we provided (at least one of them):

Install Java on your computer, as before.
Download jes-nc.zip and unpack it on your computer.
Go to http://www.jython.org and install Jython on your computer.
Get a command prompt (on Windows: Start menu, Programs, Accessories, Command Prompt).
cd into the directory where you put JES.
Type jython JESProgram.py

Slower, More Detailed Directions

First, install Java on your computer. Use java-install on the CD, or download from http://java.sun.com/j2se/1.4.1/download.html.
Now, download Jython. You can get it from http://www.jython.org, or download jython-21.class from right here. Download it to a known place, like C:\jython. (You will have to create that directory, in your C: drive.) Downloading the .class file doesn't mean that you're done!. You now have to install the .class file.
- Open up a Command Prompt. On Windows XP, that's in Start Menu to All Programs to Accessories to Command Prompt. It may be in different places on different platforms.
- cd to wherever you put the .class file, e.g., type "cd c:\jython" and hit Enter. (You'll have to hit Enter after every command in the Command Prompt.)
- Now, type java jython-21 NOTE: Do NOT type the .class part!
- Walk through the installation. It'll ask you where to install jython. I suggest picking the same directory as you put the .class file, e.g., C:\jython.
- A new folder will be created named jython-2.1. This is where Jython is now installed. The complete path will be C:\jython\jython-2.1 (assuming that you did install it in "C:\jython" as suggested).
Next, download JES. If you know how to unzip something, grab jes-nc.zip. Otherwise, download jes-nc.exe and execute the file.
- You'll be asked where to save the JES files. Save the extracted files into the Jython-2.1 directory, e.g., C:\jython\jython-2.1.
- You'll now have a new directory inside of jython-2.1 named jes-nc. This means that the complete path to JES is C:\jython\jython-2.1\jes-nc.
Finally, you're ready to run JES. This is the step that you need to repeat whenever you start JES.
- Again, open up a command prompt.
- Type "cd c:\jython\jython-2.1" to get to Jython.
- Now type "jython jes-nc\JESProgram.py" Case matters here. This says "Execute the jython file in this directory, and take as input the JESProgram.py file in the jes-nc subdirectory."
- ALTERNATIVELY: Instead of that last step, type "cd c:\jython\jython-2.1\jes-nc" and then ..\jython JESProgram.py. That's two periods, a slash, then "jython" - space - and "JESProgram.py". If you're getting an error about missing files, try this approach.

If you have memory problems

This is tricky, but it's okay. Open Notepad (start from the Start Menu – it's probably in Accessories) and edit the file "jython" in the C:\jython\jython-2.1 directory. You'll see a bunch of stuff ending in the word "java". Right after that, insert the characters:
-Xmx256m
Make sure that there are spaces to either side. Save the "jython" file, then try again. This will reserve 256 Mb for Jython, which should be plenty.

On my Mac OS X computer, my "jython" command looks like this:
"/System/Library/Frameworks/JavaVM.framework/Versions/1.3.1/Home/bin/java" -Xmx256m -Dpython.home="/Users/guzdial/jython-2.1" -classpath "/Users/guzdial/jython-2.1/jython.jar:$CLASSPATH" "org.python.util.jython" "$@"

You can ignore 90% of this. Just insert the -Xmx256m to get the memory right.

"Did I do it right?"

Here's how to check if you got it right.

In a Command Prompt, type the things in typewriter font:

cd c:\jython

(If that fails, you didn't create the right directories and nothing will work.)

dir

(You'll see a bunch of text, one part of which should now show a directory named jython-2.1)

cd jython-2.1
dir

(You should now see a directory named jes-nc and a file named jython.bat)

 cd jes-nc

(You should now see a whole bunch of files, one of which is JESProgram.py

 ..\jython JESProgram.py

NOTE

If you are still getting "Exception in thread "main" java.lang.NoClassDefFoundError: JESProgram" then you're NOT following the above directions. You can't get that error from these directions! And if you follow these directions, you should NOT be double-clicking on a JES batch file nor a Jython batch file. You'll be starting JES from a command prompt.

Please post here if this worked for you!

Worked on Win98 SE Spanish Edition! - Jose

I'm trying it right now. First, how do you unpack it. I downloaded it then it disappeared. Second, I went to Accessories and I don't see Command Prompt. And lastly, I don't understand what you are saying to do in the last 2 steps. I'm sorry if you have to say it again.

You'll need WinZip to unpack it. On different Windows, Command Prompt might be in different places. "cd" is a command (change directory). You have to use "cd" to move to a different directory on your computer. Type it like you see me typing JES commands. That last point is also a command. When you're in the same directory as JESProgram.py, you can use Jython to start JES. Mark Guzdial

Do I have to have a zip drive for this? What does it mean to "unpack" it? I tried to download Jython from the website, but I never get the option to actually download it? Any suggestions???

For the "Command Prompt" look for "MS-DOS" (Startup - Programs).

"Unpack it" basically means that the file is compressed and should be uncompressed with a program such as Winzip. - Jose

Like Jose said. You can get Winzip from http://www.winzip.com Mark Guzdial

To get Jython:
http://sourceforge.net/project/showfiles.php?group_id=12867&release_id=67726

You'll probably want to download jython-21.class (that worked for me, Win98SE). - Jose

seriously this is confusing. i havent worked in ms-dos directly in a really long time. i dont want to do anything wrong that will mess up my computer any further. could someone give detailed step by step directions for windows98? thanks :\

None of this will mess up your computer – we don't mess with the registry or anything like that. Mark Guzdial

thank you! everything worked!
BUT
now i need to figure out how to run the program. i tried to do what the directions above says but i got the error message "bad command or file name" when typing in "jython jes-nc/JESProgram.py"
what can i do to run JES?

It Worked HALELUYAH!!!!!!!! Thank you for all the help.

so you click on the batch file "jython" but then what? how do you get jes to run?

Follow the directions – note that it never says to click on the batch file "Jython".

I've gotten everything but the very last command to work: Now type "jython jes-nc/JESProgram.py"
Mine is also saying "Bad command or File Name"
Has anyone figured out how to fix this problem?

It means that you're in the wrong directory. Type the command "dir". If you don't see the file "jython," then you're in the wrong directory. See the above detailed directions on how to check if you did it right. Mark Guzdial

I still get the NoClassDefFoundError even after doing it the alternative way.

Now I am stumped. You must have some software that is really, REALLY interfering with Java. Please contact your TA to work with you individually on a fix. Mark Guzdial

I have gotten to the last step and when I try to run JES it almost opens then give me the message that it can't find the JESIntro.txt file. Anyone know what to do? Sorry for posting this to both places...

This means that you didn't get all the files off the CD or out of the zip. There is a file JESIntro.txt that must be in your JES directory. Email me and I'll send it to you, or get it out of the zip file. Mark Guzdial

C:\Jython\jython-2.1\jes>JES
Exception in thread "main" java.lang.NoClassDefFoundError: JESProgram

Why do I get this error?

Try the FAQ page or the top of this page.

IT FINALLY WORKED!!

C:\Jython\jython-2.1\jes-nc>..\jython JESProgram.py

 SUCCESS :D

you have the wrong backslash up there i think... that was part of the problem for me.

THANK YOU FOR ALL THE HELP!

it worked! it worked! thank you, thank you, thank you!!!!!

I tested this setup on redhat 9 and it works, you just gotta make slight changes to what is written here. Make sure to edit PATH so you can type jython at anytime in the console.

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