YET another double-clicking a jar question!

Question

Hi all.
Sorry about this but I've been searching this forum for the last couple of hours and I still can't figure out why I can't double-click my jar file.
I've 'jarred' my application into a file named <i>parserTTe.jar</i>.
This jar includes a package named <i>parser</i>, wich includes the main class <i>Parser</i>, and several other subpackages.
In the manifest file (created by ant 1.5), there is an entry as follows:
Main-Class: parser.Parser
followed by a couple of blank lines.
The main method of <i>Parser</i> class demands as an argument the path to the file to parse.
Now, if I run the command line <b>java -jar parserTTe.jar <i>pathtosomefile</i></b>, everything works smoothly.
As the parser does its job, I can watch its verbose flowing in the command line window.
If I double-click the jar file, though, <b>nothing happens</b> and I would expect that a <i>java.lang.ArrayIndexOutOfBounsException</i> would be thrown, as it does when I simply run <b>java parser.Parser</b>.
If instead of double-clicking the jar, I run the command line <b>parserTTe.jar <i>pathtosomefile</i></b> or just <b>parserTTe.jar</b>, still nothing happens, the command line just refreshes.
My WNT is set to recognize jar files as Executable Jar Files and the open action is set as follows:
C:\...\javaw.exe" -jar "%1".
I've tried changing this to <i>java.exe</i> instead of <i>javaw.exe</i> but then I get a <i>java.lang.ArrayIndexOutOfBounsException</i>, either if I specify the path to the file to parse or not.
Currently I'm bypassing this problem using a <i>parserTTe.bat</i> file, wich works, of course, but I'm annoyed for not understanding what's wrong: why can't I run the jar file directly?
Thanks for your help!

Answer 1

And where do you expect that argument to come from if
you double-click to run the class? That's why you are
getting the array index exception, because your class
is being called with no parameters. You need to
redesign your class so that it prompts the user for
the file name; and since it's being run via javaw.exe,
it will have to use a GUI to prompt. A JFileChooser
would be a good choice.Please look closer to my description: I said I'd be expecting that exception to be thrown because of what you say but the problem is that it doesn't.
In fact, nothing happens when I double click it, or when I run it directly from the command line, passing along the needed argument or not.
Let us forget about the double-clicking that I won't use anyway.
What puzzles me is that I should be able to run that jar as if it was a bat file. I do it all the time with other apps I've built, although none of them requires a starting argument...
Like I explained, I thought it could be something related with the javaw.exe so I set WNT to open jar files with java.exe and not javaw.exe.
The double-clicking resulted in a DOS Prompt window that opened and closed before I could see what happened. So I thought: it's ok. It threw an exception because no argument was passed.
Then I tried to run the jar from the command line passing the argument but the exception was thrown again, though, wich I didn't understand why.
Basically, that's it.
Thanks anyway for your time.