您的位置：首页 > 其它

AJAX

2014-04-22 09:59 375 查看

AJAX 的小应用，小范围刷新，判断用户名是否已经注册。

我最后才发现传值的时候如果是中文就会出现乱码问题，所有我用了网上教的两次编码1次解码去解决问题了。

1、页面代码

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP '14-4-21_AJAS_logon.jsp' starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->

</head>
<script type="text/javascript">
var xhr=null;

function checkUname(){
var username=document.myform.uname.value;
if(username==""||username==null){
document.getElementById("msgDiv").innerHTML="<font color='red'>请输入用户名</font>";
}

if(window.ActiveXObject){
xhr=new ActiveXObject("Microsoft.XMLHTTP");
}else{
xhr=new XMLHttpRequest();//只对非IE浏览器生效

}

var url="http://localhost:8080/Five_0001_Kt/TestServlet_005_14421_Login?uname="+username;
url=encodeURI(url);
url=encodeURI(url); //两次编码
xhr.onreadystatechange=haolejiaowo;   //当核心对象状态发生改变，它的处理函数
xhr.open("post",url,true);
xhr.send(null);

}
function haolejiaowo(){
if(xhr.readyState==4&&xhr.status==200){
var result=xhr.responseText;//得到远程服务器返回的结果
if(result.indexOf("true")!=-1){
document.getElementById("msgDiv").innerHTML="<font color='red'>用户名已存在</font>";;
}else{
document.getElementById("msgDiv").innerHTML="可以注册";
}
}
}

</script>

<body>
<form action="#" method="post" name="myform" >

<input type="text" name="uname" onblur="checkUname()"/>
<div id="msgDiv" style="display:inline">aaa</div>
<br/>
<input type="submit"value="注册">
</form>

</body>
</html>

2、servlet代码

package PractiseServlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestServlet_005_14421_Login extends HttpServlet {

public boolean isExist(String name){
boolean flag=false;
String []names={"admin","xiaopang","房智晨"};
for(String s:names){
if(name.equals(s)) flag=true;
}
return flag;
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doPost(request, response);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=utf-8");

PrintWriter out = response.getWriter();

String username=request.getParameter("uname");
username = java.net.URLDecoder.decode(username, "UTF-8");//一次解码
System.out.println(username);
boolean flag=isExist(username);
out.println(flag);

out.flush();
out.close();

}

}

3、页面效果

内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理

标签：

相关文章推荐

新的分享

章节导航