You can create a action that call metadata extraction api and node api to extracte metadata from pdf and move this node to target space. this action will be used as a “Rule Action”.
Then creating a rule that watches for new or updated pdf files and then runs the action when you upload files into specify folder.
By creating an action you have two options
1.Create a javascript file and ,and execute it using "Execute Script" action.
2.Write a java action executer class and Configure the action in Spring