private void InitSchema(Object obj)
    {
        Class classInfo = obj.getClass();
        
        if (fieldsMap == null || SchemaClassName != classInfo.getName())
        {
            fieldsMap = new HashMap<String, Field>();
        }
        SchemaClassName = classInfo.getName();
        Field[] fields = classInfo.getFields();

        for (int i = 0; i < fields.length; i++)
        { 
            fieldsMap.put(fields[i].getName(), fields[i]);
        }
    }