Storing Ordering in database from a listbox or Grid

package j30itlj4$v2;
public class Person {
 
	private String firstname;
	private String lastname;
 
	public Person(String firstname, String lastname) {
		super();
		this.firstname = firstname;
		this.lastname = lastname;
	}
	public String getFirstname() {
		return firstname;
	}
	public void setFirstname(String firstname) {
		this.firstname = firstname;
	}
	public String getLastname() {
		return lastname;
	}
	public void setLastname(String lastname) {
		this.lastname = lastname;
	}
 
 
}

package j30itlj4$v2;

import java.util.ArrayList;
import java.util.List;
import org.zkoss.zk.ui.Component;
import org.zkoss.zk.ui.event.DropEvent;
import org.zkoss.zk.ui.event.Event;
import org.zkoss.zk.ui.event.EventListener;
import org.zkoss.zk.ui.util.GenericForwardComposer;
import org.zkoss.zul.Column;
import org.zkoss.zul.Columns;
import org.zkoss.zul.Grid;
import org.zkoss.zul.Hlayout;
import org.zkoss.zul.Label;
import org.zkoss.zul.ListModelList;
import org.zkoss.zul.Listbox;
import org.zkoss.zul.Listcell;
import org.zkoss.zul.Listhead;
import org.zkoss.zul.Listheader;
import org.zkoss.zul.Listitem;
import org.zkoss.zul.ListitemRenderer;
import org.zkoss.zul.Row;
import org.zkoss.zul.RowRenderer;
import org.zkoss.zul.Window;
public class MyComposer extends GenericForwardComposer {
 
	private ListModelList model;
	private Window win;
	private Grid grid;
	private Listbox listbox;
 
	public MyComposer(){
		List list = new ArrayList();
		list.add(new Person("Lee", "CW"));
		list.add(new Person("Lin", "Dan"));
		list.add(new Person("Peter", "Gade"));
		list.add(new Person("Taufik", "Hidayat"));
		model = new ListModelList(list);
	}
	/* (non-Javadoc)
	 * @see org.zkoss.zk.ui.util.GenericForwardComposer#doAfterCompose(org.zkoss.zk.ui.Component)
	 */
	@Override
	public void doAfterCompose(Component comp) throws Exception {
		super.doAfterCompose(comp);
		Hlayout hl = new Hlayout();
		final Listbox listbox = new Listbox();
		final Grid grid = new Grid();
		Columns cls = new Columns();
		Column cl = new Column("Column1");
		cls.setParent(grid);
		cl.setParent(cls);
		Listhead lh = new Listhead();
		Listheader lher = new Listheader("Column2");
		lher.setSort("auto(lastname)");
		lh.setParent(listbox);
		lher.setParent(lh);
 
		listbox.setWidth("300px");
		grid.setWidth("300px");
		listbox.setItemRenderer(new ListitemRenderer(){
			public void render(final Listitem listitem, Object arg1) throws Exception {
				listitem.setDraggable("true");
				listitem.setDroppable("true");
				listitem.addEventListener("onDrop", new EventListener(){
					public void onEvent(Event event) throws Exception {
						ListModelList lml = (ListModelList) listbox.getModel();
						Listitem dragged = (Listitem) ((DropEvent)event).getDragged();
 
						Person p = (Person) lml.get(dragged.getIndex());
						lml.remove(dragged.getIndex());
						lml.add(listitem.getIndex(), p);
						grid.setModel(lml);
					}
 
				});
				Person p = (Person)arg1;
				Listcell listcell = new Listcell();
				listcell.setParent(listitem);
				new Label(p.getLastname()).setParent(listcell);
			}
		});
		grid.setRowRenderer(new gridRenderer());
		listbox.setModel(model);
		grid.setModel(model);
		hl.setParent(win);
		grid.setParent(hl);
		listbox.setParent(hl);
	}
 
	class gridRenderer implements RowRenderer{
		public void render(Row row, Object arg1) throws Exception {
			Person p = (Person)arg1;
			new Label(p.getFirstname()).setParent(row);
		}
	}
 
 
}

<zk>
<window id="win" title="test" apply="j30itlj4$v2.MyComposer" border="normal">
</window>
</zk>