Have a single ptviewer jar file per website

PTViewer is a Java applet that is supplied as a file called ptviewer.jar.

Typically it is embedded in a web-page using applet or object HTML tags, the ptviewer.jar file location is specified in the archive attribute:

 <applet
   archive="/path/to/ptviewer.jar"
   code="ptviewer.class"
   width="320"
   height="200">
   <param
     name="file"
     value="panorama.jpg" />
 </applet>

This has caused problems in the past with some Java virtual machines which have interpreted the archive path differently, generally web-site creators place the JAR archive in the same directory as the HTML page and specify the location like so:

 archive="ptviewer.jar"

To avoid having superfluous copies of the applet on a server, you can use this apache directive to make it appear that a single copy appears to exist in every directory:

 RewriteEngine on
 RewriteRule (^|/)ptviewer\.jar$ /websites/mysite/html/ptviewer.jar

(replace /websites/mysite/html/ptviewer.jar with the system path on your server)

This requires apache with mod_rewrite enabled. You can place the directive in the httpd.conf configuration file or in a .htaccess file in the root of your site.