Launching WebStart Applications via a CGI Script
This section outlines the steps required to create a CGI Perl script that
can be used to launch a WebStart application. This section assumes
experience in writing both CGI Perl scripts and WebStart JNLP files.
Many NeXtMidas-based applications come with web page front ends that allow
users to easily select the data they wish to view. Using that information
a customized NeXtMidas session is launched via WebStart.
Unfortunately JNLP files are static and can not accept options passed in
from a web form. One way to get around this is to write a CGI Perl script
that will take those options and serve out a dynamically-generated JNLP
file.
-
Generate the normal JNLP file and NeXtMidas JAR files that would be
used to launch a static version of the application
(see Building WebStart Applications for
details).
-
Take the JNLP file and create a Perl file out of it. This can be done by
putting print commands around each line of the JNLP file. Make sure to
escape any special characters (e.g. '
" ' becomes
'\" ').
-
Very Important: Change the Perl script and remove the
href that refers to the JNLP file. It's usually of the
form
<jnlp spec="1.0+" href="app_name.jnlp">
If you omit this step Java WebStart will attempt to start a JNLP file in
the codebase .
-
Modify the Perl script to include any necessary processing for getting
the command line arguments.
-
Edit the line containing
<argument> APP_NAME </argument>
line so that it reads
<argument> APP_NAME arg1 arg2 ... argN </argument>
where arg1 , arg2 , ...,
argN are the arguments to pass to the application.
-
Save the Perl script in one of the CGI areas of the server (usually
cgi-bin ). Give it the name app_name.pl .
-
Open a web browser and run the script manually to test it:
http://server_name/cgi-bin/app_name.pl?arg1&arg2&...&argN
-
If all works well, the web page front-end can now be configured to run
the CGI Perl script in order to bring up the WebStart Application.
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