Not sure what you are trying to achieve ? Just trying to print the Query used ?
If Yes, just assign the query to a String before executing, and use the string for executing and the same for printing.
Does this help ?
String str = "SELECT full_name, employee_number FROM per_all_people_f WHERE employee_number = '" +empno +"’”;
rs = st.executeQuery(str);
//Stt = rs.getStatement().toString();