Using java read message payloads

Dear experts,

I am looking to read using BAPI/RFC from java based on given date as input , all messageid with respective payload texts.

Anybody had a probe on this earlier ?.I have setup JCO (sapjco3.jar),i am also able to execute rfc on my XI box.

Now issue is to find the rfc or bapi which could do the required job

Pl help.