login.jsp
<%@ 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 'login.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"> --> <script type="text/javascript" src="js/jquery-1.8.3.js"> </script> </head> <script type="text/javascript">
方法一
function chkName() { var name = $("#username").val(); //alert(name); $.ajax( { url : "server.jsp", data : "name=" + name, //发送数据 dataType : "text", //响应数据类型 type : "get", //请求发方式 success : function(value) { //成功之后 if ($.trim(value) == "true") { $("#msg").html("用户已存在！"); } else { $("#msg").html("此用户可用！"); } } }); } </script>
方法二
<script type="text/javascript">
function chkName() {
var name = $("#username").val();
$.get("server.jsp","name="+name,function(value){
if ($.trim(value) == "true") {
$("#msg").html("用户已存在！");
} else {
$("#msg").html("此用户可用！");
}
})
}
</script>
方法三
<script type="text/javascript">
function chkName() {
var name = $("#username").val();
$.post("server.jsp","name="+name,function(value){
if ($.trim(value) == "true") {
$("#msg").html("用户已存在！");
} else {
$("#msg").html("此用户可用！");
}
})
}
</script>
方法四
<script type="text/javascript">
function chkName() {
var name = $("#username").val();
$("#msg").load("server.jsp","name=" + name, function(value) {
//alert();
if ($.trim(value) == "true") {
$("#msg").html("用户已存在！");
} else {
$("#msg").html("此用户可用！");
}
});
}
</script>
<body> <form action="login.action" method="post"> <div> 用户名： <input name="username" type="text" value="" id="username" onblur="chkName()" /> <span id="msg"></span> </div> <input type="submit" value="提交" /> </form> </body> </html>
server.jsp
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <% String name=request.getParameter("name"); if("sa".equals(name)){ out.print("true"); }else{ out.print("false"); } %>