本文实例为大家分享了java异步登录的具体代码，供大家参考，具体内容如下
1.LoginServletAjax.java
package com.scce.servlet; 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; import net.sf.json.JSONObject; import com.scce.dao.AdminUserDao;import com.scce.pojo.AdminUser; public class LoginServletAjax extends HttpServlet { @Override protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); String method = request.getMethod(); if (method.equals("POST")) { doLoginAjax(request, response); } else if (method.equals("GET")) { } } public void doLoginAjax(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { PrintWriter out = response.getWriter(); // 用户名 String username = request.getParameter("username"); // 密码 String password = request.getParameter("password"); String msg = ""; AdminUserDao adminUserDao = new AdminUserDao(); AdminUser adminUser = adminUserDao.queryUser(username, password); if (adminUser != null) { msg="登录成功！"; String jsonObj= JSONObject.fromObject(adminUser).toString(); out.print("{/"Msg/":/""+msg+"/",/"rows/":"+jsonObj+"}"); System.out.println("{/"Msg/":/""+msg+"/",/"rows/":"+jsonObj+"}"); } else { msg="用户名或者密码不正确！"; out.print("{/"Msg/":/""+msg+"/"}"); } out.flush(); out.close(); } }2.test2.html
<!DOCTYPE html><html> <head> <title>chapter3-test2</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <link rel="stylesheet" href="../UI/themes/icon.css" type="text/css"></link> <link rel="stylesheet" href="../UI/themes/default/easyui.css" type="text/css"></link> <!-- <script type="text/javascript" src="../js/jquery-1.8.2.min.js"></script> --> <script type="text/javascript" src="../UI/jquery.min.js"></script> <script type="text/javascript" src="../UI/jquery.easyui.min.js"></script> <script type="text/javascript" src="../UI/locale/easyui-lang-zh_CN.js"></script> <script type="text/javascript"> //string number boolean null object undefined function $(function() { $("#LoginAdd").dialog({ title : "用户登录", collapsible : 'true', width : 300, height : 200, buttons : [ { text : '登录', iconCls : 'icon-add', handler : function() { console.info("用户登录！"); ajaxFrm();//ajax提交表单的函数 } } ] }); }); function ajaxFrm() { //------------------------注释的是ajax提交方法---------------------------- var LoginList = $("#LoginList"); $.ajax({ url : '../LoginServletAjax?tag=test',//相对路径访问 type : 'POST', //提交请求的方式 data : $('#form1').serialize()+'&names=liuqin&age=26',//将表单参数序列化，发送到服务器的数据(提交额外的参数) dataType : 'json', //预期服务器返回的数据类型-json object success : function(data) {//请求成功后将调用此方法var data = {"Msg":"登录成功","rows":{"username":"admin",...}} console.info(data);//调试代码 $.messager.alert("提示", data.Msg); LoginList.html("");//清空数据 if (data.rows) { var stra = LoginList.html() + "用户名:" + data.rows.username + "--密码：" + data.rows.password + "<br/>"; LoginList.html(stra); } }, error : function(error) { //请求失败时将调用此方法 console.info(error); } }); /*var LoginList = $("#LoginList"); $("#form1").form("submit", { url: "../LoginServletAjax?tag=test", onSubmit: function (param) { //提交额外的参数 param.name="liuqin"; param.age=27; var username = $("#username").val(); var password = $("#password").val(); if (username.length == 0 || password.length == 0) { $.messager.alert('警告', '请输入用户名和密码'); return false; } return true; }, success: function (data) { //var data = eval('(' + data + ')'); var data = $.parseJSON(data);//服务器端返回json字符串转成json对象-js object console.info(data); $.messager.alert("提示", data.Msg); LoginList.html("");//清空数据 if (data.rows) { var stra = LoginList.html() + "用户名:" + data.rows.username + "--密码：" + data.rows.password + "<br/>"; LoginList.html(stra); } } });*/ }</script> </head> <body> <div id="LoginAdd"> <form id="form1" method="post"> <table> <tr> <td> 用户名： </td> <td> <input id="username" name="username" > </td> </tr> <tr> <td> 密码： </td> <td> <input id="password" name="password" type="password"> </td> </tr> </table> </form> </div> <div id="LoginList"> 用户信息加载中...... </div> <video controls="controls" src="../video/B4934A0C53FC55703BFE3F6843E66166.mp4" type="video/mp4"> Your browser does not support the video tag. </video> </body></html>以上就是本文的全部内容，希望对大家学习java程序设计有所帮助。