I’ve really only done this via socket communication. See here: URCap Sample: URCap-ScriptCommunicator
Basically you use the exportStrings() method and just send “get_actual_tcp_pose()” (and you should send get_actual_joints() and save that too) and store the result to the data model on the Java side.
As for reading the input, I’ve done this via a thread running in Java that checks for the input state. See this post for details: How to read the status of digital outputs? - #5 by eric.feldmann