[SOLVED] Ajax Servlet : How to give path of .java file in req.open(GET,url,true)

Verve · February 2, 2008

Hi,

I am new to ajax. I am using a jsp from which a servelt is called which will do validation. I running application from tomcat. But in firebug following error is shown :

req.responseXML has no properties

var message = req.responseXML.getElementsByTagName("valid")[0].child

If in url(see jsp below) i am not giving .java then file not found error is shown. I tried by calling same code from a jsp and gave its path in url and it was working. I have no idea why it is not calling java file. please help !!!!!!!!!!!!!

Files are given below, both files are in same folder

Validate.jsp

<html>

<head>

var req;

var target;

var isIE;

function initRequest(url) {

if (window.XMLHttpRequest) {

req = new XMLHttpRequest();

} else if (window.ActiveXObject) {

isIE = true;

req = new ActiveXObject("Microsoft.XMLHTTP");

}

function validateUserId() {

if (!target){ target = document.getElementById("userid");}

var url = "http://localhost:8080/XXAjax/ValidationServlet.java?id=" + escape(target.value);

alert(url);

initRequest(url);

req.onreadystatechange = processRequest;

req.open("GET", url, true);

req.send(null);

}

function processRequest() {

if (req.readyState == 4) {

if (req.status == 200) {

var message = req.responseXML.getElementsByTagName("valid")[0].childNodes[0].nodeValue;

setMessageUsingDOM(message);

var submitBtn = document.getElementById("submit_btn");

if (message == "false") {

submitBtn.disabled = true;

} else {

submitBtn.disabled = false;

}

// This function is not used for now. You will use this later.

function setMessageUsingInline(message) {

mdiv = document.getElementById("userIdMessage");

if (message == "false") {

mdiv.innerHTML = "<div style=\"color:red\">Invalid User Id</div>";

} else {

mdiv.innerHTML = "<div style=\"color:green\">Valid User Id</div>";

}

// (5) Function in which message indicating the validity of the data gets displayed

// through the "userIdMessage" <div> element.

function setMessageUsingDOM(message) {

var userMessageElement = document.getElementById("userIdMessage");

var messageText;

if (message == "false") {

userMessageElement.style.color = "red";

messageText = "Invalid User Id";

} else {

userMessageElement.style.color = "green";

messageText = "Valid User Id";

}

var messageBody = document.createTextNode(messageText);

// if the messageBody element has been created simple replace it otherwise

// append the new element

if (userMessageElement.childNodes[0]) {

userMessageElement.replaceChild(messageBody, userMessageElement.childNodes[0]);

} else {

userMessageElement.appendChild(messageBody);

}

function disableSubmitBtn() {

var submitBtn = document.getElementById("submit_btn");

submitBtn.disabled = true;

}

</script>

<title>Form Data Validation using AJAX</title>

</head>

<tr>

<td>

<input type="text"

size="20"

id="userid"

name="id"

onkeyup="validateUserId()">

</td>

<%-- The "userIdMessage" div element specifies the location where input validation

message gets displayed. --%>

<td>

</td>

</tr>

<tr>

</td>

</tr>

</table>

</form>

</body>

</html>

ValidationServlet.java

import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;

import java.util.*;

public class ValidationServlet extends HttpServlet {

private ServletContext context;

private HashMap accounts = new HashMap();

// Initialize the "accounts" hashmap. For the sake of this exercise,

// two accounts are created with names "greg" and "duke" during

// initialization of the Servlet.

public void init(ServletConfig config) throws ServletException {

this.context = config.getServletContext();

accounts.put("greg","account data");

accounts.put("duke","account data");

}

public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException {

// Extract the data of the input form field whose name is "id"

String targetId = request.getParameter("id");

if ((targetId != null) && !accounts.containsKey(targetId.trim())) {

response.setContentType("text/xml");

response.setHeader("Cache-Control", "no-cache");

response.getWriter().write("<valid>true</valid>");

} else {

response.setContentType("text/xml");

response.setHeader("Cache-Control", "no-cache");

response.getWriter().write("<valid>false</valid>");

}

public void doPost(HttpServletRequest request, HttpServletResponse response)

throws IOException, ServletException {

String targetId = request.getParameter("id");

if ((targetId != null) && !accounts.containsKey(targetId.trim())) {

accounts.put(targetId.trim(), "account data");

request.setAttribute("targetId", targetId);

context.getRequestDispatcher("/Test.html").forward(request, response);

} else {

context.getRequestDispatcher("/error.jsp").forward(request, response);

}

Thanks in advance .....

Verve

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[SOLVED] Ajax Servlet : How to give path of .java file in req.open(GET,url,true)

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