How to get table fields programatically?

Question

I am using a table component with associated data provider. In the same form, I need to have a drop down with the values same as the columns/fields of the table. I am looking at the APIs to find a way to access the table fields/columns, so that I can have them in the drop down, but I can't find out.
Please note that I need to access the field names (i.e First_Name, Last_Name, User_Name, etc.) not the field values (i.e Joe, Bloe, jbloe, etc.) If it was field values, there are tons of example out there. Actually, I am trying to build searhing, where users can pick a field from the drop down, and type text to search on that field. See the screenshots here:
http://bedriven.blogspot.com/2006/08/filtering-data-table-in-java-studio.html

Answer 1

I tried this:
tableRowGroup.getSourceData().getFieldKeys()but, the problem is, it gives me the field names, but not the display values. I want to use the display values (i.e Last Name) for dropdown text, and field keys (i.e user_last_name) for dropdown values.
I ended up using this code to get the list of column fileds (field name in database) and the column header (display value in table header):
        Iterator it=getTableRowGroup1().getTableColumnChildren();
        Option options[]=new Option[getTableRowGroup1().getColumnCount()];
        int i=0;
        while (it.hasNext()){
            TableColumn column=(TableColumn)it.next();
            if (column.getSort()!=null){
                options=new Option(column.getSort().toString(), column.getHeaderText());
}else{
options[i]=new Option(column.getHeaderText(), column.getHeaderText());
i++;
This approach works fine. The only problem is that getTableColumnChildren returns size 0 when the page is loaded the first time. It works fine on the subsequent post backs. You can see this reported by other users as well:
http://swforum.sun.com/jive/thread.jspa?threadID=101630&tstart=0