Problems with AJAX and XML

[Anand Ramachandran]

Hi
I am unable to parse XML data sent to an AJAX call from a servlet.
The data passes into the AJAX call but I get NULL when i try to
parse it .

JSP page
--------

<script type="text/javascript">
var xmlHttp;
var requestType = "";
function createXMLHttpRequest()
{
if (window.ActiveXObject)
{
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
else if (window.XMLHttpRequest) {
xmlHttp = new XMLHttpRequest();
}
}

function startRequest()
{

createXMLHttpRequest();
xmlHttp.onreadystatechange = handleStateChange;
xmlHttp.open("GET","chat", true);
xmlHttp.send(null);
}

function handleStateChange()
{
if(xmlHttp.readyState == 4)
{
if(xmlHttp.status == 200)
{
alert(xmlHttp.responseText);
var xmlDoc = xmlHttp.responseXML;

var northNode = xmlDoc.getElementsByTagName("message")[0];

var northStates = northNode.getElementsByTagName("type");

var currState=northStates[0];

var temp="np";

temp=currState.childNodes[0].nodeValue;
alert(temp);
}
}
}

function listNorth()
{

var xmlDoc = xmlHttp.responseXML;

var northNode = xmlDoc.getElementsByTagName("message")[0];

var northStates = northNode.getElementsByTagName("type");

var currState=northStates[1];

var temp=currState.childNodes[1].nodeValue;

}

</script>

Servlet
--------
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub

System.out.println("Reaching the servlet");

PrintWriter out = response.getWriter();

out.print("<?xml version=1.0 encoding=UTF-8?>");
out.print("<message>");
out.print("<type>House</type>");
out.print("</message>");
}

[Ulf Dittmer]

Welcome to JavaRanch.

What is null - xmlDoc? northNode? northStates? currState? temp?

I'm not sure if it matters, but the XML being sent by the servlet doesn't look well-formed - it has no double quotes around the attributes.

Also, you're not setting the transfer encoding of the servlet output. I don't think it matters here, but if the XML claims to be in UTF-8, then you need to make sure that what the servlet sends really is UTF-8.