<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<script type="text/javascript">
function checkUser(userName)
{
if(userName.value=="")
{
alert("input your name please!");userName.focus();return;
}
else
{
creatRequest("checkUser.jsp?user="+userName.value);
}
}
function creatRequest(url)
{
http_request=false;
http_request=new XMLHttpRequest();
if(!http_request)
{
alert("no creatation");
return false;
}
http_request.onreadystatechange=getResult;//不加括号的函数
http_request.open("GET",url,true);
http_request.send(null);
}
function getResult()
{
if(http_request.readyState==4 )
{
if(http_request.status==200)
{
document.getElementById("toolTip").innerHTML=http_request.responseText;
document.getElementById("toolTip").style.display="block";
}
else
{ alert(http_request.status);
}
}
}
</script>
<body>
<form method="post" action="" name="form1">
name:<input type="text" name="username" id="username" size="32"/>
<button type="button" onclick="checkUser(form1.username);">register</button>
<br>
<div id="toolTip">show toolTip here</div>
</form>
</body>
</html>
执行顺序是
form1, 输入用户名，
checkuser()
creatRequest()
getResult()
最后在toolTip显示结果。
把checkUser.jsp 写成了checkerUser.jsp
所以一直找不到页面，报404错误
checkUser.jsp
<%@page import="java.util.Arrays"%>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%
String[] userList={"killer","mr","smith"};
String user=new String(request.getParameter("user").getBytes("ISO-8859-1"),"UTF-8");
Arrays.sort(userList);
int result=Arrays.binarySearch(userList, user);
if(result>-1)
{
out.println("sorry,the name is occupied!");
}
else
{
out.println("congulation,the name is usable");
}
%>
</body>
</html>
