Hi,
Below I have code that contains ajax on a JSP. The JSP runs the Servlet which gets a parameter from the JSP and returns the exact same input field's value. For some reason, it is returning a null though. Can someone please assist?
Servlet:
package Web;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Date;
public class fieldProcessing extends HttpServlet {
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
Date time = new Date();
int i = 0;
String uN = request.getParameter("username");
try {
out.println(uN);
//out.println(time.getHours() + ":" + time.getMinutes() + ":" + time.getSeconds() + " Num: " + ++i + " ya");
} finally {
out.close();
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* Handles the HTTP <code>GET</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
/**
* Returns a short description of the servlet.
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}JSP:
<html>
<head>
<title></title>
<script type="text/javascript">
function init(){
window.setInterval("ajaxFunction()",1000);
}
function ajaxFunction() {
var xmlhttp;
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
}
else if (window.ActiveXObject) {
// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
else {
alert("Your browser does not support XMLHTTP!");
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4) {
document.myForm.time.value=xmlhttp.responseText;
document.getElementById("testText").rows[0].cells[0].innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("GET","fieldProcessing",true);
xmlhttp.send(null);
}
</script>
</head>
<body onload="init();">
<form name="myForm">
Name: <input type="text" name="username" onkeyup="ajaxFunction();" />
Time: <input type="text" name="time" />
<table border="1" id="testText">
<tr>
<td>
I bet you $20 this will change soon!
</td>
</tr>
</table>
</form>
</body>
</html>I created this in Netbeans, I'm sure it would work if you just created a new Servlet and titled it "fieldProcessing.java" and a new JSP and titled it "index.jsp".
Thanks!
-Ashton.