STRUTS2 Ajax to verify that the user name exists
<%@ page contenttype= "text/html; charset=gb2312 "language=" java "import=" java.sql.* "errorpage=" "%>"
<!doctype HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "http://www.w3.org/tr/xhtml1/dtd/ Xhtml1-transitional.dtd ">
<meta http-equiv= "Content-type" content= "text/html; charset=gb2312 "/>
<title> Untitled Document </title>
<body>
<tr>
<TD class= "label" > household name:</td>
<td><s:textfield onblur= "Checkusername" (This, '/register!check.action ') "CSS tutorial class=" Inputstyle "Name=" User.Name "/></td>
<TD width= "150px;" ><span id= "Namemessage" ></span><s:fielderror cssclass= "Filederrorclass" fieldname= "name"/> </td>
</tr>
</body>
XML document
<package name= "Ajaxuser" extends= "Web Effects On-default" >
<action name= "register" class= "Com.test.user.registeraction" >
<result name= "Input" >/user/register. Web effects p/jsp.html target=_blank >jsp Tutorials </result>
<result name= "Success" >/user/register_message.jsp</result>
<result name= "Myjson" type= "JSON" ></result>
</action>
</package>
Action. Code
public string Check () throws exception {
Actioncontext CTX = Actioncontext.getcontext ();
HTTPS tutorial Ervletrequest request = (httpservletrequest) ctx.get (servletactioncontext.http_request);
String username = Request.getparameter ("InputName");
if (Checkuserexit (username)) {
This.registered = true;
}
return "Myjson";
}
JS Code
var xmlhttp;
var currentname;
function Createxmlhttprequest () {
if (window.activexobject) {
XMLHTTP = new ActiveXObject ("Microsoft.XMLHTTP");
}
else if (window.xmlhttprequest) {
XMLHTTP = new XMLHttpRequest ();
}
}
function Checkusername (field,url) {
var name = Field.value;
if (name== "| | name.length<3) {
document.getElementById ("Namemessage"). Innerhtml= "username should be no less than 3 bits";
Return
}else {
Createxmlhttprequest ();
url = url+ "? inputname=" +name;
Currentname = name;
Xmlhttp.open ("get", url);
Xmlhttp.onreadystatechange = callback;
Xmlhttp.send (NULL);
}
}
function callback () {
if (xmlhttp.readystate = = 4) {
if (Xmlhttp.status = = 200) {
var user = eval (' + xmlhttp.responsetext + ') ');
if (user.registered) {
document.getElementById ("Namemessage"). innerHTML = "<font color= ' Red ' >" +currentname+ ", has been registered!</font>";
}else {
document.getElementById ("Namemessage"). innerHTML = "<font color= ' green ' >" +currentname+ ", can register!</font>" ;
}
}
}
}