There are already some Nagios plugins out there, which can be used to check the memory heap size of Weblogic or similar web application servers, but the ones I tried to use were either not working or horribly complicated to use. These are enough reasons to launch another plugin!
From now on you can use the plugin check_weblogic_heap. This plugin will get the current memory utilization of the checked web application (defined by port). For more information and download, go to the check_weblogic_heap page.
As with the other plugins, I'll be happy to get feedback and of course also feature patches or bugfixes.