Servlet+AJAX -- I am getting request.status = 404 Error

[Joseph Bashir]

I am making a file upload progress bar using ajax. When I run the application on my local network the file is uploaded showing the progress bar. But when I upload the same application on remote server and test it live, the application does not work. In javascript I get req.status = 404. Another thing, in browser's statusbar I see this url http://pagead2.googlesyndication.com/. I dont know why my application is being directed to this url. Please help.

Here is the full source code.

var req;
function ajaxFunction() {
var url = "servlet/FileUploadServlet";
if (window.XMLHttpRequest) { // Non-IE browsers
req = new XMLHttpRequest();
alert("after creating instance: "+req.status);
req.onreadystatechange = processStateChange;
try {
req.open("GET", url, true);
} catch (e) {
alert("Exception: "+e);
}
req.send(null);
} else if (window.ActiveXObject) { // IE Browsers
req = new ActiveXObject("Microsoft.XMLHTTP");
if (req) {
req.onreadystatechange = processStateChange;
req.open("GET", url, true);
req.send();
}
}
}
 
function processStateChange() {
/**
*StateDescription
*0The request is not initialized
*1The request has been set up
*2The request has been sent
*3The request is in process
*4The request is complete
*/
alert("req.readyState: "+req.readyState); 
if (req.readyState == 4) {
alert("req.status: "+req.status);  // Here I get 404 instead of 200
if (req.status == 200) { // OK response
var xml = req.responseXML;
// No need to iterate since there will only be one set of lines
var isNotFinished = xml.getElementsByTagName("finished")[0];
var myBytesRead = xml.getElementsByTagName("bytes_read")[0];
var myContentLength = xml.getElementsByTagName("content_length")[0];
var myPercent = xml.getElementsByTagName("percent_complete")[0];
// Check to see if it's even started yet
if ((isNotFinished == null) && (myPercent == null)) {
document.getElementById("initializing").style.visibility = "visible";
// Sleep then call the function again
window.setTimeout("ajaxFunction();", 100);
} else {
document.getElementById("initializing").style.visibility = "hidden";
document.getElementById("progressBarTable").style.visibility = "visible";
document.getElementById("percentCompleteTable").style.visibility = "visible";
document.getElementById("bytesRead").style.visibility = "visible";
myBytesRead = myBytesRead.firstChild.data;
myContentLength = myContentLength.firstChild.data;
 
if (myPercent != null) { // It's started, get the status of the upload
myPercent = myPercent.firstChild.data;
document.getElementById("progressBar").style.width = myPercent + "%";
document.getElementById("bytesRead").innerHTML = myBytesRead + " of " + myContentLength + " bytes read";
document.getElementById("percentComplete").innerHTML = myPercent + "%";
// Sleep then call the function again
window.setTimeout("ajaxFunction();", 100);
} else {
document.getElementById("bytesRead").style.visibility = "hidden";
document.getElementById("progressBar").style.width = "100%";
document.getElementById("percentComplete").innerHTML = "Done!";
window.setTimeout("window.location.reload();", 3000);
//window.location.href=window.location.href;
}
}
} else {
//alert("req.statusText: "+req.statusText);
alert("There was a problem retrieving the XML data:\n" + req.statusText);
}
}
}

Here is the servlet:

public class FileUploadServlet extends HttpServlet implements Servlet {
private static final long serialVersionUID = 2740693677625051632L;
 
public FileUploadServlet(){
super();
}

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    PrintWriter out = response.getWriter();
    HttpSession session = request.getSession();
    FileUploadListener listener = null; 
    StringBuffer buffy = new StringBuffer();
    long bytesRead = 0,contentLength = 0; 
    
    // Make sure the session has started
    if (session == null){
    return;
    }
    else if (session != null){
    // Check to see if we've created the listener object yet
    listener = (FileUploadListener)session.getAttribute("LISTENER");
    
    if (listener == null){
    return;
    }else{
    // Get the meta information
        bytesRead = listener.getBytesRead();
    contentLength = listener.getContentLength();
    }
    }
    
    /*
     * XML Response Code
     */
    response.setContentType("text/xml");
    
    buffy.append("<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?>\n");
    buffy.append("<response>\n");
    buffy.append("\t<bytes_read>" + bytesRead + "</bytes_read>\n");
    buffy.append("\t<content_length>" + contentLength + "</content_length>\n");
 
    // Check to see if we're done
    if (bytesRead == contentLength){
    buffy.append("\t<finished />\n");
    
    // No reason to keep listener in session since we're done
session.setAttribute("LISTENER", null);
    } else {
    // Calculate the percent complete
    long percentComplete = ((100 * bytesRead) / contentLength);  

    buffy.append("\t<percent_complete>" + percentComplete + "</percent_complete>\n");
    }

    buffy.append("</response>\n");
 
    out.println(buffy.toString());
    out.flush();
    out.close();
    }
    
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
 // create file upload factory and upload servlet
FileItemFactory factory = new DiskFileItemFactory();
ServletFileUpload upload = new ServletFileUpload(factory);
 
// set file upload progress listener
FileUploadListener listener = new FileUploadListener();

HttpSession session = request.getSession(false);

session.setAttribute("LISTENER", listener);

// upload servlet allows to set upload listener
upload.setProgressListener(listener);
 
List uploadedItems = null;
FileItem fileItem = null;


ResourceBundle resourceBndl = ResourceBundle.getBundle("resources.ApplicationResources", Locale.getDefault(), this.getClass().getClassLoader());
String str_url = resourceBndl.getString("url.com");

URLConnection urlConn = null;

URL url = new URL(str_url);
        String boundary = MultiPartFormOutputStream.createBoundary();
        urlConn = MultiPartFormOutputStream.createConnection(url);
        urlConn.setRequestProperty("Accept", "*/*");
        urlConn.setRequestProperty("Content-Type", MultiPartFormOutputStream.getContentType(boundary));
        urlConn.setRequestProperty("Connection", "Keep-Alive");
        urlConn.setRequestProperty("Cache-Control", "no-cache");
        //code = ((HttpURLConnection)urlConn).getResponseCode();
        
        ServletContext sc = getServletContext();
        String filePath = sc.getRealPath("/itemimages");
        DiskFileUpload fu = new DiskFileUpload();
        fu.setSizeMax(-1L);
        fu.setRepositoryPath(filePath);
            
        try {
// iterate over all uploaded files
uploadedItems = upload.parseRequest(request);

Iterator i = uploadedItems.iterator();

int inc = 0;

while (i.hasNext()){
fileItem = (FileItem) i.next();

if (fileItem.isFormField() == false) { 
if (fileItem.getSize() > 0) {
File uploadedFile = null; 
String myFullFileName = fileItem.getName();
//System.out.println("myFullFileName: "+myFullFileName); 
String serverImage = "";
String slashType = (myFullFileName.lastIndexOf("\\") > 0) ? "\\" : "/"; // Windows or UNIX
int startIndex = myFullFileName.lastIndexOf(slashType);

String extension = myFullFileName.substring(myFullFileName.lastIndexOf("."),myFullFileName.length()).toLowerCase();
 
// Ignore the path and get the filename
serverImage = myFullFileName.substring(startIndex + 1, myFullFileName.length());
String itemname = (String)session.getAttribute("itemname");

//String username = session.getAttribute("username").toString();
Integer userId = (Integer)session.getAttribute("userid");

serverImage = itemname+"_"+userId+"_"+inc+extension;
                inc++;


// Create new File object
uploadedFile = new File(filePath, serverImage);

// Write the uploaded file to the system
fileItem.write(uploadedFile);

session.setAttribute("userId",(Integer)session.getAttribute("userid"));
        session.setAttribute("serverImage"+"_"+userId+"_"+inc, serverImage);
        
        
}
}
}

} catch (FileUploadException e){
e.printStackTrace();
} catch (Exception e){
e.printStackTrace();
} 
}
    
}

[Bear Bibeault]

You are using a page-relative URL. Bad idea.

Use a server-relative URL in which the URL begins with the context path.

[Joseph Bashir]

What is server-relative URL. Can you please suggest where should I make the change in the code?

Joseph

[Bear Bibeault]

See this JSP FAQ entry. It focuses on images, but also applies to your issue.

[Joseph Bashir]

Hi

I have tried a lot but still there is no success. I am still getting req.status = 404. And though I have set response.setContentType("text/xml"); in the servlet, but in the javascript code req.getAllResponseHeaders() shows Content-Type: text/html.

In browser's statusbar I still see this url http://pagead2.googlesyndication.com/. This url is not mentioned in the code anywhere than why is my application being directed to this url. Please help, its very urgent.


Joseph

[ January 05, 2008: Message edited by: Joseph Bashir ]

[ January 05, 2008: Message edited by: Joseph Bashir ]
[ January 05, 2008: Message edited by: Joseph Bashir ]

[Ulf Dittmer]

As was mentioned before, you should use an absolute URL, not a relative URL.

The response is HTML because it is an error message; 404 means that whatever you were addressing is not present on the server (which is no surprise, given the relative URL you're using).