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I have made this web application in Java using Netbeans as the IDE.
I was mainly working over my AJAX code, but when i hit and trial over the code using System.out.println(..); The code was not able to go through the Servlet.I have attached a zip file which contains the whole code.
The application was mainly to check the validity whether the value entered in the textfield is a number or not.I do want to know where i went wrong.
Thank you
The servlet
package Serv;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class ValidationServlet
*/
@WebServlet(description = "Validation through ajax", urlPatterns = { "/ValidationServlet" })
public class ValidationServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public ValidationServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
PrintWriter out = response.getWriter();
boolean passed = validateInteger(request.getParameter("number"));
response.setContentType("text/xml");
response.setHeader("cache-Control","no-cache");
System.out.print("YES");
String message = "You have entered an invalid number.";
if(passed){
message = "You have entered a valid number.";
}
out.println("<response>");
out.println("<passed>" + Boolean.toString(passed) + "</passed>");
out.println("<message>" + message + "</message>");
out.println("</response>");
out.close();
}
private boolean validateInteger(String number){
boolean isValid = true;
if(number!=null){
try{
Integer.parseInt(number);
}
catch(NumberFormatException e){
isValid = false;
}
}
isValid = false;
return isValid;
}
}
The Javascript code
var xmlHttp;
function createXMLHttpRequest(){
if(window.ActiveXObject){
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}else if(window.XMLHttpRequest){
xmlHttp = new XMLHttpRequest();
}
}
function validate(){
createXMLHttpRequest();
var number = document.getElementById("number");
var url = "ValidationServlet?number=" + escape(number.value);
xmlHttp.open("GET", url, true);
xmlHttp.onreadystatechange = callback;
xmlHttp.send(null);
}
function callback(){
if(xmlHttp.readyState == 4){
if(xmlHttp.status == 200){
var mes = xmlHttp.responseXML.getElementsByTagName("message")[0].firstChild.data;
var val = xmlHttp.responseXML.getElementsByTagName("passed")[0].firstChild.data;
setMessage(mes,val);
}
}
}
function setMessage(){
var messageArea = document.getElementById("numMessage");
var fontColor = "red";
if(isValid =="true"){
fontColor = "green";
}
messageArea.innerHTML = "<font color ="+fontColor +">" + message + "</font>";
}
The HTML code
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <script type ="text/javascript" src="validationScript.js"></script> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Insert title here</title> </head> <body> <h1>Ajax Validation Example</h1> Number:<input type="text" size="10" id="number" onchange= "validate();"/> <div id = 'numMessage'></div> </body> </html>
The XML code
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
<display-name>Valid</display-name>
<servlet>
<servlet-name>ValidationServlet</servlet-name>
<servlet-class> ValidationServlet</servlet-class>
</servlet>
<welcome-file-list>
<welcome-file>validation.html</welcome-file>
</welcome-file-list>
<servlet-mapping>
<servlet-name>ValidationServlet</servlet-name>
<url-pattern>/ValidationServlet</url-pattern>
</servlet-mapping>
</web-app>
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