使用Ajax验证用户是否可以注册

来源：互联网发布：66是什么意思网络用语6 编辑：程序博客网时间：2024/05/23 15:41

1．Java代码如下:

package com.eduask;

import java.io.IOException;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

//测试用户名在服务器中的测试;

public class Demo2 extends HttpServlet{

@Override

protected void service(HttpServletRequest req, HttpServletResponse resp)

throws ServletException, IOException {

resp.setContentType("text/html;charset=utf-8");

String name=req.getParameter("name1");

name=new String(name.getBytes("ISO8859-1"),"utf-8");

if("tom".equals(name)){

resp.getWriter().write("<font color=red>该用户已存在！</font>");

}else{

resp.getWriter().write("<font color=blue>该用户可以注册！</font>");

}

2.demo2.jsp代码如下:

<body>

请输入用户名: <input id="input1" type="text" name="name1">

var input1=document.getElementById("input1");

input1.onblur=function(){

var xhr=getXhr();

xhr.onreadystatechange=function(){

if(xhr.readyState==4){

if(xhr.status==200){

var msg=xhr.responseText;

var span1=document.getElementById("span1");

span1.innerHTML=msg;

}

xhr.open("get","/ajax/Demo2?name1="+input1.value,true);

xhr.send(null);

}

function getXhr(){

var xml;

if(window.XMLHttpRequest){

xml=new XMLHttpRequest();

} else{

xml=new ActiveXObject("microsoft,xmlhttp");

}

return xml;

}

</script>

3.web.xml配置文件如下:

<servlet-name>Demo2</servlet-name>

<servlet-class>com.eduask.Demo2</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>Demo2</servlet-name>

<url-pattern>/Demo2</url-pattern>

</servlet-mapping>

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