利用Ajax檢測(cè)用戶(hù)名是否被占用的完整實(shí)例
適合人群：ajax和jquery入門(mén)
采用ajax實(shí)現(xiàn)用戶(hù)名驗(yàn)證
使用jquery給出提示信息
用戶(hù)注冊(cè)的時(shí)候，使用ajax實(shí)現(xiàn)檢測(cè)用戶(hù)名是否已經(jīng)被注冊(cè)過(guò)，很多細(xì)節(jié)沒(méi)有實(shí)現(xiàn)，給大家做個(gè)簡(jiǎn)單普及。
<%@ page language="java" contenttype="text/html; charset=utf-8"
pageencoding="utf-8"%>
<!doctype html public "-//w3c//dtd html 4.01 transitional//en" "http://www.w3.org/tr/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>用戶(hù)注冊(cè)頁(yè)面</title>
<script src="https://libs.baidu.com/jquery/1.8.3/jquery.min.js"></script>
<script type="text/javascript">
var xmlhttp;
function createxmlhttprequest(){
if(window.xmlhttprequest){
xmlhttp = new xmlhttprequest();
}else if(window.activexobject){
xmlhttp = new activexobject("microsoft.xmlhttp");
}
}
function validate(account){
createxmlhttprequest();
xmlhttp.open("get","validateservlet?account="+account,true);
xmlhttp.onreadystatechange = callback;
xmlhttp.send(null);
}
function callback(){
if(xmlhttp.readystate==4){
if(xmlhttp.status==200){
var text = xmlhttp.responsetext;
if(text=="true"){
//document.getelementbyid("msg").innerhtml = "該手機(jī)號(hào)已經(jīng)被注冊(cè)過(guò)";
$("#msg").text("該手機(jī)號(hào)已經(jīng)被注冊(cè)");
$("#sub").attr("disabled","true");//添加disabled屬性，讓按鈕不可用
}else{
//document.getelementbyid("msg").innerhtml = "";
$("#msg").text("");
$("#sub").removeattr("disabled");//移除disabled屬性，讓按鈕可用
}
}else{
alert("請(qǐng)求失敗，錯(cuò)誤碼="+xmlhttp.status);
}
}
}
function checkinfo(){
var account = $("#account").val();
var pwd1 = $("#pwd1").val();
var pwd2 = $("#pwd2").val();
if(account==""||account==null){
$("#msg").text("賬號(hào)不能為空");
$("#sub").attr("disabled","true");
return false;
}
if(pwd1==""||pwd1==null||pwd2==""||pwd2==null||pwd1!=pwd2){
$("#info").text("密碼不能為空或者兩次密碼不一致");
$("#sub").attr("disabled","true");
return false;
}
$("#msg").text("");
$("#info").text("");
$("#sub").removeattr("disabled");
}
function submit(){
checkinfo();
$("#reg").submit();
}
</script>
</head>
<body>
<form id="reg" name="reg" action="registerservlet" method="post">
賬號(hào)：<input type="text" name="account" id="account" onblur="validate(this.value);">
<span id="msg" style="color:red">請(qǐng)輸入手機(jī)號(hào)<br>
密碼：<input type="password" id="pwd1" name="password1" onblur="checkinfo();"><br>
確認(rèn)密碼：<input type="password" id="pwd2" name="password2" onblur="checkinfo();">
<span id="info" style="color:red"><br>
<input type="button" id="sub" value="提交" onclick="submit();">
</form>
</body>
</html>
下面是validateservlet模擬實(shí)現(xiàn)，沒(méi)有做真正的數(shù)據(jù)庫(kù)表數(shù)據(jù)檢測(cè)，大家自行完成。
package com.ambow.servlet;
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;
@webservlet("/validateservlet")
public class validateservlet extends httpservlet {
private static final long serialversionuid = 1l;
public validateservlet() {
super();
}
protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
printwriter pw = response.getwriter();
string account = request.getparameter("account");
system.out.println("account"+account);
if("123".equals(account)) {
pw.print("true");
}else {
pw.print("false");
}
}
protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
doget(request, response);
}
}
到此這篇關(guān)于利用ajax檢測(cè)用戶(hù)名是否被占用的文章就介紹到這了,更多相關(guān)ajax檢測(cè)用戶(hù)名被占用內(nèi)容請(qǐng)搜索碩編程以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持碩編程！
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