本文實例講述了Ajax異步方式實現登錄與驗證的詳細代碼，。具體如下：

登錄代碼

這個是使用Bootstrap3的組件功能實現的

<div class="login_con_R">      <h4>登錄</h4>      <FORM id="loginFormId" class="form-horizontal" action="login" method="post">        <div class="form-group input-group">          <span class="input-group-addon"><span class="glyphicon glyphicon-user"></span></span>          <input type="text" class="form-control" placeholder="用戶名" name="username" id="j_username" value="koala">        </div>        <div class="form-group input-group">          <span class="input-group-addon"><span class="glyphicon glyphicon-lock"></span></span>          <input type="password" name="password" id="j_password" class="form-control" placeholder="密碼" value="888888"/>        </div>               <div class="form-group input-group" style="margin-top: 45px;">          <button type="button" class="btn btn-primary btn-block" id="loginBtn">登錄</button>        </div>      </FORM>    </div>

異步登錄請求的代碼

<script>  $(function(){    var btnLogin = $('#loginBtn');    var form = $('#loginFormId');    $('body').keydown(function(e) {      if (e.keyCode == 13) {        dologin();      }    });    btnLogin.on('click',function() {      dologin();    });    var dologin = function() {      var userNameElement = $("#j_username");      var passwordElement = $("#j_password");      var username = userNameElement.val();      var password = passwordElement.val();      if (!Validation.notNull($('body'), userNameElement, username, '用戶名不能為空')) {        return false;      }      if (!Validation.notNull($('body'), passwordElement, password, '密碼不能為空')) {        return false;      }      btnLogin.attr('disabled', 'disabled').html('正在登錄...');      var param = form.serialize();      $.ajax({        url: contextPath+"/login.koala",        dataType: "json",        data: param,        type: "POST",        success: function(data){          if(data.success){            $('.login_con_R').message({              type: 'success',              content: '登錄成功！'            });            /*這里使用的異步請求，當請求登錄成功的時候，重新定位到index界面*/            window.location.href=contextPath+"/index.koala";          }else{            btnLogin.removeAttr('disabled').html('登錄');            $('.login_con_R').message({              type: 'error',              content: data.errorMessage            });          }        }      });    };    });   </script>

使用到的驗證js代碼Validation.js

Validator = {  Require : {expression:/.+/,errorMsg:"該字段不能為空"},  Email : {expression:/^/w+([-+.]/w+)*@/w+([-.]//w+)*/./w+([-.]/w+)*$/,errorMsg:"Email格式不正確"},  Mobile:{expression:/^(1[3|5|8]{1}/d{9})$/,errorMsg:"手機格式不正確"},  TelePhone:{expression:/^(((0/d{2,3}-)?/d{7,8}(-/d{4})?))$/,errorMsg:"電話號碼格式不正確"},  IdCard:{expression:/^/d{15}(/d{2}[A-Za-z0-9])?$/,errorMsg:"身份證號碼格式不正確"},  Number:{expression:/^-?(/d+|[1-9]/d*/./d+|0/./d*[1-9]/d*|0?/.0+|0)$/,errorMsg:"僅支持數字"},  English:{expression:/^[A-Za-z]+$/,errorMsg:"僅支持英文字符"},  Chinese:{expression:/^[/u0391-/uFFE5]+$/,errorMsg:"僅支持中文字符"},  URL:{expression:/^http:////[A-Za-z0-9]+/.[A-Za-z0-9]+[//=/?%/-&_~`@[/]/':+!]*([^<>/"/"])*$/,errorMsg:"URL地址格式不正確"},  Regex:{errorMsg:"格式不正確"},  UnSafe : /^(([A-Z]*|[a-z]*|/d*|[-_/~!@#/$%/^&/*/./(/)/[/]/{/}<>/?/////'/"]*)|.{0,5})$|/s/,  IsSafe : function(str){return !this.UnSafe.test(str);},  SafeString : {expression:"this.IsSafe(value)",errorMsg:"僅支持中文字符"},  ErrorItem : [document.forms[0]],  ErrorMessage : ["以下原因導致提交失敗：/t/t/t/t"],  Validate : function(theForm, mode){    var obj = theForm || event.srcElement;    var count = obj.elements.length;    this.ErrorMessage.length = 1;    this.ErrorItem.length = 1;    this.ErrorItem[0] = obj;    for(var i=0;i<count;i++){      with(obj.elements[i]){        if(disabled)continue;        var _dataType = getAttribute("dataType");        if(typeof(_dataType) == "object" || typeof(this[_dataType]) == "undefined") continue;        this.ClearState(obj.elements[i]);        if(getAttribute("require") == "false" && value == "") continue;        var errorMsg = getAttribute("errorMsg")? getAttribute("errorMsg") : this[_dataType].errorMsg;        errorMsg = errorMsg || "invalid";        var validateExpr = getAttribute("validateExpr");        validateExpr = validateExpr || this[_dataType].expression;        switch(_dataType){          case "Date" :          case "Repeat" :          case "Range" :          case "Compare" :          case "Custom" :          case "Group" :          case "Limit" :          case "LimitB" :          case "SafeString" :            if(!eval(validateExpr)) {              this.AddError(i, errorMsg);            }            break;          default :            if(!eval(validateExpr).test(value)){              this.AddError(i, errorMsg);            }            break;        }      }    }    if(this.ErrorMessage.length > 1){      var content = this.ErrorMessage[1].replace(//d+:/," ");      var $element = $(this.ErrorItem[1]);      var name = $element.attr('name');      if(name.indexOf('DTO') != -1){        name = name.split('.')[1];      }      var $targetElement = $element;      var $tempElement = $targetElement.closest('form').find('#' + name + 'ID');      if($tempElement.hasClass('select')){        $targetElement = $tempElement;      }      showErrorMessage($element.closest('.modal'), $targetElement, content);      return false;    }    return true;  },  limit : function(len,min, max){    min = min || 0;    max = max || Number.MAX_VALUE;    return min <= len && len <= max;  },  LenB : function(str){    return str.replace(/[^/x00-/xff]/g,"**").length;  },  ClearState : function(elem){    with(elem){      if(style.color == "red")        style.color = "";      var ligertipid = getAttribute("ligertipid");      if(ligertipid && ligertipid != ""){        removeAttribute("ligertipid");        $(elem).ligerHideTip();      }    }  },  AddError : function(index, str){    this.ErrorItem[this.ErrorItem.length] = this.ErrorItem[0].elements[index];    this.ErrorMessage[this.ErrorMessage.length] = this.ErrorMessage.length + ":" + str;  },  Exec : function(op, reg){    return new RegExp(reg,"g").test(op);  },  compare : function(op1,operator,op2){    switch (operator) {      case "NotEqual":        return (op1 != op2);      case "GreaterThan":        return (op1 > op2);      case "GreaterThanEqual":        return (op1 >= op2);      case "LessThan":        return (op1 < op2);      case "LessThanEqual":        return (op1 <= op2);      default:        return (op1 == op2);    }  },  MustChecked : function(name, min, max){    var groups = document.getElementsByName(name);    var hasChecked = 0;    min = min || 1;    max = max || groups.length;    for(var i=groups.length-1;i>=0;i--)      if(groups[i].checked) hasChecked++;    return min <= hasChecked && hasChecked <= max;  },  IsDate : function(op, formatString){    formatString = formatString || "ymd";    var m, year, month, day;    switch(formatString){      case "ymd" :        m = op.match(new RegExp("^//s*((//d{4})|(//d{2}))([-./])(//d{1,2})//4(//d{1,2})//s*$"));        if(m == null ) return false;        day = m[6];        month = m[5]--;        year = (m[2].length == 4) ? m[2] : GetFullYear(parseInt(m[3], 10));        break;      case "dmy" :        m = op.match(new RegExp("^//s*(//d{1,2})([-./])(//d{1,2})//2((//d{4})|(//d{2}))//s*$"));        if(m == null ) return false;        day = m[1];        month = m[3]--;        year = (m[5].length == 4) ? m[5] : GetFullYear(parseInt(m[6], 10));        break;      default :        break;    }    var date = new Date(year, month, day);    return (typeof(date) == "object" && year == date.getFullYear() && month == date.getMonth() && day == date.getDate());    function GetFullYear(y){return ((y<30 ? "20" : "19") + y)|0;}  }};var Validation = {  notNull: function($container, $element, content, errorMessage) {    if (isNull(content)) {      showErrorMessage($container, $element, errorMessage);      return false;    }    return true;  },  email: function($container, $element, content, errorMessage) {    var reg = new RegExp(/^(/w)+(/./w+)*@(/w)+((/./w{2,3}){1,3})$/);    if (!reg.test(content)) {      showErrorMessage($container, $element, errorMessage);      return false;    }    return true;  },  serialNmuber: function($container, $element, content, errorMessage) {    var reg = new RegExp(/^[0-9a-zA-Z_-]*$/);    if (!reg.test(content)) {      showErrorMessage($container, $element, errorMessage);      return false;    }    return true;  },  number: function($container, $element, content, errorMessage) {    var reg = new RegExp(/^[0-9]*$/);    if (!reg.test(content)) {      showErrorMessage($container, $element, errorMessage);      return false;    }    return true;  },  humanName: function($container, $element, content, errorMessage) {    var reg = new RegExp(/(^[A-Z a-z]*$)|(^[/u4e00-/u9fa5]*$)/);    if (!reg.test(content)) {      showErrorMessage($container, $element, errorMessage);      return false;    }    return true;  },  checkByRegExp: function($container, $element, regExp, content, errorMessage){    var reg = new RegExp(regExp);    if (!reg.test(content)) {      showErrorMessage($container, $element, errorMessage);      return false;    }    return true;  }};/** * 檢查是否為空 */var isNull = function(item){  if(item == null || item == "" || item.replace(/(^/s*)|(/s*$)/g, "") == "" ){    return true;  }  return false;};/** * 顯示提示信息 */var showErrorMessage = function($container, $element, content){  $element.popover({    content: content,    trigger: 'manual',    container: $container  }).popover('show').on({      'blur': function(){        $element.popover('destroy');        $element.parent().removeClass('has-error');      },      'keydown': function(){        $element.popover('destroy');        $element.parent().removeClass('has-error');      }    }).focus().parent().addClass('has-error');};