JSONWriter writer = new JSONStringer().object();
for (Iterator<UIColumn> iter = extendedDataTable.getChildColumns(); iter.hasNext();) {
UIColumn col = iter.next();
writer.key(col.getId()).value(col.isVisible() ? TRUE : FALSE);
}
value = new JSONObject(writer.endObject().toString());
} catch (JSONException e) {
e.printStackTrace();
}
}//createDefaultColumnsVisibility