HP - UFT: GetCellData gives a JSON request

Im trying to test some Java Program with UFT.

The problem is the following: I need to use GetCellData to extract various values from a JavaTable, and when i try to do so, the value of the extracted data, sometimes is null (""), or other times, i extract a JSON Post Message that the program sends. Any ideas on another method to read the the content of the java table?