<%@ 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 'index.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"> <script type="text/javascript" src="js/jquery-1.12.4.min.js"></script> <script type="text/javascript"> function valDateEmian(hag){ //createGetHttpRequst(hag.value); createPostHttpRequst(hag.value); } var xmlHttpRequest; function createGetHttpRequst(name){ xmlHttpRequest=new XMLHttpRequest(); //2调用回调函数 xmlHttpRequest.onreadystatechange=callBack; //3初始化xmlhttpreqost组件 xmlHttpRequest.open("GET","UserServlet?name="+name,true); //4发送请求 xmlHttpRequest.send(null); } function createPostHttpRequst(name){ xmlHttpRequest=new XMLHttpRequest(); xmlHttpRequest.onreadystatechange=callBack; xmlHttpRequest.open("POST","UserServlet",true); xmlHttpRequest.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); xmlHttpRequest.send("name="+name+"&opr=index"); } //设置回调函数 function callBack(){ if (xmlHttpRequest.readyState==4 && xmlHttpRequest.status==200) { var date =xmlHttpRequest.responseText; document.getElementById("emain").innerHTML=date; } } </script> </head> <body> 邮箱 ：<input type="text" onblur="valDateEmian(this)" /><span id="emain"> </span> 用户名 ：<input type="text" /> <span id="emain"> </span> 密码 ：<input type="text" /> <span id="emain"> </span> </body> </html>