Ajax question

[Jian Yi]

Hi,

I'm new to Ajax. Does Ajax have a limit on how big the xml document returned by the jsp should be? I have this weird problem... My Jsp returns an xml document like this:

<?xml version="1.0" ?>
<Entry>
<Dealer>407209</Dealer>
<Device>33333</Device>
</Entry>
<Entry>
<Dealer>405A11</Dealer>
<Device>33334</Device>
</Entry>

And FireBug gave me an error:

junk after document element

<Entry> ^

This <Entry> refers to the second <Entry> element. Why is this happening? How can I fix it?

Thanks,
Yi

P.S. my jsp looks like this:

<%@ page contentType="text/xml"%>
<%@ page language="java" import="java.util.*,com.vw.dlrvas.util.*" %>
 
<%! 
private WASConnectionPool getPool(){
return (WASConnectionPool)getServletConfig().
getServletContext().getAttribute("dbPool");
}
%>
 
<%
String allDevices = request.getParameter("allDevices");
Vector dealerDevices = new DbUtil().getRegisteredDevices(allDevices, getPool());
 
StringBuffer xmlMessage = new StringBuffer("<?xml version=\"1.0\" ?>\n");

for (int i = 0; i < dealerDevices.size(); i = i + 2) {
xmlMessage.append("<Entry>\n");
xmlMessage.append("<Dealer>").append((String)dealerDevices.get(i)).append("</Dealer>\n");
xmlMessage.append("<Device>").append((String)dealerDevices.get(i+1)).append("</Device>\n");
xmlMessage.append("</Entry>\n");
}

response.setContentType("text/xml");
response.setHeader("Cache-Control", "no-cache");
response.getWriter().write(xmlMessage.toString());
response.getWriter().flush();
%>

[Gregg Bolinger]

That's not valid XML. A valid XML document needs a root element. You don't have one. So you need to add something like:

<?xml version='1.0'?>
<Entries>
   <Entry>
   ...
   </Entry>
   <Entry>
   ...
   </Entry>
</Entries>

[Jian Yi]

I think I know why my program is wrong. The returned xml document can only have one root element. I should return something like this:

<?xml version="1.0" ?>
<Root>
<Entry>
<Dealer>407209</Dealer>
<Device>33333</Device>
</Entry>
<Entry>
<Dealer>405A11</Dealer>
<Device>33334</Device>
</Entry>
</Root>

Am I correct? If so, I need some assistance to parse this document. Does anyone have some sample code snippets?

Thanks!
Yi

[Eric Pascarello]

Basic idea:

var xmlDoc = req.responseXML.contentDocument;
var myEntry = xmlDoc.getElementsByTagName("Entry");

Loop

var item0 = myEntry[i].childNodes.item(0);
var item1 = myEntry[i].childNodes.item(1);

Eric

[Jian Yi]

Thank you both. There are so many nice experts out here!

[Eric Pascarello]

Who said I was nice....man I was working on my bad boy image!

Eric

[Jian Yi]

Okay, bad boy, giddy-up!