Dynamic options DWR with Tomcat

Question

I'm no javascript hacker so I'd like to get som feedback about how this problem is solved
We want to show some dynamic option from a data set which should be updatable without changing the code and is too large to send in one piece to the client (about 1000 location names and about 20 for each areacode.) I then made like this for a given area code to populate a list where every other element is a name and every other is the id using serverside java:
public java.util.ArrayList getLocationsByAreacode(int areacode) {
       java.util.ArrayList<String> list = new java.util.ArrayList<String>();
       Connection conn = null;
       PreparedStatement ps = null;
       try {
           conn = DBSettings.getConnection();
           ps = conn.prepareStatement("select location, locationid
from location join areacodes on location.areacode = areacodes.ac join
estado on estado.estadoid=areacodes.estadoid where areacode=? order by
vieworder desc, location asc ");
           ps.setInt(1, areacode);
           ResultSet rs = ps.executeQuery();
           while (rs.next()) {
               list.add(rs.getString("location"));
               list.add(rs.getString("locationid"));
       } catch (SQLException e) {
           log.error(e);
       } catch (Exception e) {
       } finally {
           try {
               conn.close();
           } catch (SQLException e) {
                 log.error(e);
           } catch (Exception e) {
                log.error(e);
       return list;
   }Thereafter this server side java is called with Ajax:
    function updateOptions(ac){
           LocationList.getLocationsByAreacode(ac, function(data){
               if (data != null){
                   dwr.util.removeAllOptions('theLocation');
                   var i=0;
                   while(i<data.length/2){
                       document.forms[0].theLocation.options[i] = new
Option(data[2*i],data[2*i+1]);
                       ++i;
               else{
   }And this actually works well but is my first non-trivial Ajax code.
Is this a proper solution? Can you see any optimization that we can make?
How does the data structure seem where every other element is name and every other is the id?
Thank you
Niklas
Edited by: Niklas on Apr 23, 2008 1:50 AM

Answer 1

I'm having the same problem. I made a very complex message board using php, DWR on Apache and Tomcat. I lost a drive and all the server setup I had done. After reinstalling the server and publishing the message board backup I can't get the DWR portion to work. I get the
type: Status report
message: Servlet dwr-invoker is not available
description: The requested resource (Servlet dwr-invoker is not available) is not available.
Any suggestions?