We have one requirement, where User will open the PDF in adobe reader and add some annotation to it and on click of the save button annotation should get exported and updated in the database.
I found out that to use exportasfdf method in adobe reader, PDF document should have Form rights access which is provided by LiveCycle Reader Extension and it is not free ware.
The above use case is already working in one of the environment using 3rd Party Plugin. (There is no LiveCycle Reader extension available)
So is there any way I can see what all is written in the plugin.
You seem determined to bypass other people's IP and we won't help with that: Adobe's business model is to sell Acrobat, or LiveCycle Reader Extensions, or possibly plug-in development licenses. Decompiling is almost always forbidden by EULA. Plugins can easily write FDF directly, no need for any magic but the plugin licensing negotiation with Adobe would be challenging, such things are usually forbidden - of course because Adobe want to sell LiveCycle software. You are free to submit FDF to a web server.