How to use Advance java function in graphical mapping in XI 2.0?

Hi,

currently I am using a simple java function to make an RFC call to R3 system.

I want to avoid making connection for each lookup. Instead I want to make a single connection for whole message queue and get the corresponding values in some array or container object.

please suggest a solution.

I think this is possible using Advance java function, but I am not able to find any example on using Advance java function at help.sap.com.

thaks in advance.