Complete validation with Ajax

Source: Internet
Author: User
Tags date format return string tostring window
Ajax business logic: A standard input box, required to enter the date format of the text, in line with the requirements of the green Word display information, otherwise use the red Word hint.

Page: validation.html

<%@ page contenttype= "text/html; CHARSET=GBK "%>
Using Ajax for validation
<script type= "Text/javascript" >
XMLHttpRequest objects
var xmlHttp;

Creating XMLHttpRequest Objects
function Createxmlhttprequest () {
if (window. ActiveXObject) {
XmlHttp = new ActiveXObject ("Microsoft.XMLHTTP");
else if (window. XMLHttpRequest) {
XmlHttp = new XMLHttpRequest ();

Validation method
function Validate () {
Creating objects
Createxmlhttprequest ();
Get Form Date value
var date = document.getElementById ("birthdate");
Submit Address
var url = "validationservlet?birthdate=" + Escape (Date.Value); ("Get", url,true);
Xmlhttp.send (NULL);

         //callback methods
           function Callback () {
           if ( Xmlhttp.readystate = = 4) {
            if (xmlhttp.status {
             var mes = XmlHttp.responseXML.getElementsByTagName ("message") [0];
                                 var val = XmlHttp.responseXML.getElementsByTagName ("passed") [0];

                                //Set hint information
                                  setmessage (Mes,val);

Set up a hint information
function Setmessage (message,isvalid) {
var Messagearea = document.getElementById ("Datemessage");
var fontcolor = "Red";
if (IsValid = = "true") {
FontColor = "green";

Messagearea.innerhtml= "<font color=" + fontcolor + ">" + message + "</font>";

Ajax Validation Example
Birth date:<input type= "text" size= "ten" id= "Birthdate"/>
<div id= "Datemessage" ></div>

Server-side code, performing validation

Import javax.servlet.*;
Import javax.servlet.http.*;
Import java.util.*;
Import Java.text.SimpleDateFormat;

public class Validationservlet extends HttpServlet {
private static final String Content_Type = "text/html;" CHARSET=GBK ";

Initialize Global Variables
public void Init () throws Servletexception {

* Process GET Requests
* @param request HttpServletRequest
* @param response HttpServletResponse
* @throws servletexception
* @throws IOException
public void doget (HttpServletRequest request, httpservletresponse response) throws Servletexception, IOException {
Response.setcontenttype (Content_Type);
Get Output Object
PrintWriter out = Response.getwriter ();

Get the date value as a parameter validation
Boolean passed = Validatedate (Request.getparameter ("birthdate"));
Response.setcontenttype ("Text/xml");
Response.setheader ("Cache-control", "No-cache");
String message = "Your have entered an invalid date.";

if (passed) {
Message = ' You have entered a valid date. '

Enter XML format string
Out.println ("<response>");
Out.println ("<passed>" + boolean.tostring (passed) + "</passed>");
Out.println ("<message>" + message + "</message>");
Out.println ("</response>");
Out.close ();

Clean up resources
public void Destroy () {

* Date of verification
* @param date String
* @return Boolean
Private Boolean validatedate (String date) {
Boolean isValid = true;
if (date!= null) {
SimpleDateFormat formatter = new SimpleDateFormat ("mm/dd/yyyy");
try {
Formatter.parse (date);
catch (Exception ex) {
System.out.println (Ex.tostring ());
IsValid = false;
IsValid = false;

return isValid;

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