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Passing command line arguments to javaws (Java WebStart) executable.

Answer 1

+2 A:

the javaws executable accepts a run-option -arg <argument> which allows the called to send arguments to the application. I think these are appended to the arguments in the jnlp file.

So your call might look like this:

javaws [options] -arg my_file.jpg http://example.org/launch.jnlp

Edit: The above solution only works with OpenJDK's javaws which accepts the -arg parameter. Another option, according to this blog post, is that you can pass arguments to the JNLP file using URL query string parameters. This will obviously only work if you execute javaws with the full URL and won't work if you access it as a download link. I have not tested this so it may or may not work.

Guss 2009-09-09 11:04:05

Hi. Thanks for the answer.This doesn't seem to work. javaws just prints general usage info.My javaws version is "Java(TM) Web Start 1.6.0_13".How come the -arg option is not documented in http://java.sun.com/javase/6/docs/technotes/tools/share/javaws.html ?Maybe you meant -open ?

karolrvn 2009-09-09 13:53:31

-open could probably satisfy me. But I will need to handle the superfluous "-open" arg in my app, in a special way. Weird, that javaws passes the "-open" to the app.

karolrvn 2009-09-09 14:05:11

Interesting. I'm using OpenJDK with IcedTea6 and now that I check its javaws supported options are very different then the javaws shipped with Sun's JDK. If this feature is important to you then maybe you could upgrade to OpenJDK. Possibly this feature will also be in Sun's JDK 7.

Guss 2009-09-09 18:27:36

Thanks for clarifying. I'm in a middle of big programming work so i will not upgrade to OpenJDK anytime soon.I'm now using "-open" arg and adapted my app to remove it from String args[]. Is "-open" supported in your JDK version?Also, if I may correct You: "different then"->"different than", i think. Or is this spelling official now?

karolrvn 2009-09-09 18:37:33

Yea, I always have problem with "then"<->"than". Its my form of dyslexia ;-) . As far as I can tell, the "special" (and silly) form of argument passing in "-open" and "-print" is not supported under OpenJDK's javaws, though you can always mimic it with `-arg -open -arg something-else`. Also -arg does not replace the arguments in the jnlp but appends to them.

Guss 2009-09-09 18:55:46

That's a weird and avoidable incompatibility, don't you think?

karolrvn 2009-09-09 18:59:25

Your spelling is very good generally.

karolrvn 2009-09-09 19:00:35

Thanks :-). Indeed it is weird (though I think the special "-open" and "-print" are even wierder). I can't find much information about this in the web so I have no idea where this came from. Other then that, I've edited my answer with a more sanctioned approach that may work.

Guss 2009-09-09 19:29:32

Geez. It seems, that -open can only take 1 argument. Semi-contrary to http://java.sun.com/javase/6/docs/technotes/tools/share/javaws.html#runoptions : <br>-open <arguments>If specified, replaces the arguments in the jnlp file with -open <arguments>.<br>It says argumentS.Anyway, the -open and -print switches aren't even listed when javaws prints its usage. This is going from weird do ugly and from ugly to evil/stupid.

karolrvn 2009-09-09 20:38:05

This is even scarier: The javaws launcher has a set of options that are supported in the current release. However, the options may be removed in a future release. ( http://java.sun.com/javase/6/docs/technotes/tools/share/javaws.html#runoptions ) . But explains the lack of -open in OpenJDK.JDK 6 is so many releases away from the first release which had javaws, and they still didn't figure out how to sanely pass CLI args?!?!? That's just unbelievable to me in general. But completely fits into the sorry state of things with javaws implementation.

karolrvn 2009-09-09 20:49:54

I think they meant that -open <args> can accept many arguments when passed in a single arg (do they then split them somehow?), so to pass "-open","1","2" you call `javaws -open "1 2"`. Maybe.

Guss 2009-09-10 08:54:45

They are not split when they come to String[] args. These would come as "1 2". That possibly makes sense for opening one file. But there are cases in which an app opens many files at once. Or open a file and specify a switch/mode. Is it so much to ask? Or do I have to split the args on spaces or whatever (not difficult really, but the shell should do it, actually, e.g. because of spaces-in-filenames and escape sequences).

karolrvn 2009-09-10 09:54:58

You are right, but you are limited by the javaws CLI. I suggest you try the "arguments in query string" method and if that doesn't work then upgrade your javaws.

Guss 2009-09-10 10:29:07

Answer 2

A:

dynamically generate the webstart jnlp file with the parameters.

$ javaws [options] http://example.org/codewriter/write.jnlp?param1=my_file.jpg

the codewriter captures the query parameter and writes out the dynamic jnlp from the parameter

Matthew 2010-09-29 15:30:16

Would not work if you are online. I am now using -open myarg and it works for the use case that i need.

karolrvn 2010-10-30 19:04:40

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Passing command line arguments to javaws (Java WebStart) executable.

How do I do this: ? If we could pass ad-hoc command-line args to javaws, then javaws apps could be more like "1st class citizen" "ordinary application". E.g. we could pass filenames of files to be opened.

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