Cas自定义登录页面Ajax实现

时间要去哪 2014-06-17

展开全文

本文是基于CAS 之自定义登录页实践及CAS 之跨域 Ajax 登录实践而实现的,主要是针对最新的Cas实现自定义登录页的Ajax跨域实现.

环境：
        cas-server-3.5.1-release
        cas地址: http://localhost:8080/cas/
        client地址: http://localhost/web

从CAS服务端生成lt及execution，在cas的 login flow 中加入 ProvideLoginTicketAction 的流，主要用于判断该请求是否是来获取 lt，在cas-server端声明获取 login ticket action 类:

org.jasig.cas.web.flow.ProvideLoginTicketAction

import javax.servlet.http.HttpServletRequest;
import org.jasig.cas.util.UniqueTicketIdGenerator;
import org.jasig.cas.web.support.WebUtils;
import org.springframework.webflow.action.AbstractAction;
import org.springframework.webflow.execution.Event;
import org.springframework.webflow.execution.RequestContext;
/**
* Opens up the CAS web flow to allow external retrieval of a login ticket.
*
* @author cydiay
*/
public class ProvideLoginTicketAction extends AbstractAction{
private static final String PREFIX = "LT";
@Override
protected Event doExecute(RequestContext context) throws Exception {
final HttpServletRequest request = WebUtils.getHttpServletRequest(context);
if (request.getParameter("get-lt") != null && request.getParameter("get-lt").equalsIgnoreCase("true")) {
final String loginTicket = this.ticketIdGenerator.getNewTicketId(PREFIX);
WebUtils.putLoginTicket(context, loginTicket);
return result("loginTicketRequested");
}
return result("continue");
}
private UniqueTicketIdGenerator ticketIdGenerator;
public void setTicketIdGenerator(final UniqueTicketIdGenerator generator) {
this.ticketIdGenerator = generator;
}
}

并且将该 action 声明在 cas-servlet.xml 中：

查看文本打印 ?

<bean id="provideLoginTicketAction" class="org.jasig.cas.web.flow.ProvideLoginTicketAction"
p:ticketIdGenerator-ref="loginTicketUniqueIdGenerator"/>

还需要定义 loginTicket 的生成页也就是当返回 loginTicketRequested 的 view：
位置/WEB-INF/view/jsp/default/ui

viewRedirectToRequestor.jsp

查看文本打印 ?

<%@ page contentType="text/html; charset=UTF-8"%>
<%
String ajax = request.getParameter("n");
//当执行Ajax自定义页面时执行以下操作
if(ajax!=null && ajax.length()>0){
response.getWriter().print(request.getAttribute("loginTicket")+"&"+request.getAttribute("flowExecutionKey"));
} else {
//正常cas执行
%>
<script>window.location.href = "/cas/login";</script>
<%
}
%>

并且需要将该 jsp 声明在 default._views.properites 中：

casRedirectToRequestorView.(class)=org.springframework.web.servlet.view.JstlView
casRedirectToRequestorView.url=/WEB-INF/view/jsp/default/ui/viewRedirectToRequestor.jsp

接下来要做的就是将该action 的处理加入到 login-webflow.xml 请求流中:

查看文本打印 ?

<on-start>
<evaluate expression="initialFlowSetupAction" />
</on-start>
<action-state id="provideLoginTicket">
<evaluate expression="provideLoginTicketAction"/>
<transition on="loginTicketRequested" to="viewRedirectToRequestor" />
<transition on="continue" to="ticketGrantingTicketExistsCheck" />
</action-state>
<view-state id="viewRedirectToRequestor" view="casRedirectToRequestorView" model="credentials">
<binder>
<binding property="username" />
<binding property="password" />
</binder>
<on-entry>
<set name="viewScope.commandName" value="'credentials'" />
</on-entry>
<transition on="submit" bind="true" validate="true" to="realSubmit">
<set name="flowScope.credentials" value="credentials" />
<evaluate expression="authenticationViaFormAction.doBind(flowRequestContext, flowScope.credentials)" />
</transition>
</view-state>
<decision-state id="ticketGrantingTicketExistsCheck">
<if test="flowScope.ticketGrantingTicketId != null" then="hasServiceCheck" else="gatewayRequestCheck" />
</decision-state>

调整 CAS Server端，使其适应 Iframe 方式登录，并使其支持回调。
打开 login-webflow.xml，找到 <action-state id="generateServiceTicket"> 的 Flow-Action 配置项:

查看文本打印 ?

<action-state id="generateServiceTicket">
<evaluate expression="generateServiceTicketAction" />
<transition on="success" to="loginResponse" />
<transition on="error" to="loginResponse" />
<transition on="gateway" to="redirect" />
</action-state>

再新增 loginResponse Action配置项：

查看文本打印 ?

<action-state id="loginResponse">
<evaluate expression="ajaxLoginServiceTicketAction" />
<transition on="success" to="warn" />
<transition on="error" to="viewLoginForm" />
<transition on="local" to="viewAjaxLoginView" />
</action-state>

再调整，当验证失败后，也需要判断是否是 iframe/ajax登录：

查看文本打印 ?

<action-state id="realSubmit">
<evaluate
expression="authenticationViaFormAction.submit(flowRequestContext, flowScope.credentials, messageContext)" />
<transition on="warn" to="warn" />
<transition on="success" to="sendTicketGrantingTicket" />
<transition on="error" to="loginResponse" />
</action-state>

还需要配置 viewAjaxLoginView 的 state:

查看文本打印 ?

<end-state id="viewAjaxLoginView" view="viewAjaxLoginView" />

接着，再定义 ajaxLoginServiceTicketAction Bean 吧，直接在 cas-servlet.xml 声明该 bean:

查看文本打印 ?

<bean id="ajaxLoginServiceTicketAction" class="com.unknow.cas.server.web.AjaxLoginServiceTicketAction"/>

查看文本打印 ?

import javax.servlet.http.HttpServletRequest;
import org.apache.commons.lang.BooleanUtils;
import org.apache.commons.lang.StringUtils;
import org.jasig.cas.authentication.principal.Service;
import org.jasig.cas.web.support.WebUtils;
import org.springframework.webflow.action.AbstractAction;
import org.springframework.webflow.execution.Event;
import org.springframework.webflow.execution.RequestContext;
public final class AjaxLoginServiceTicketAction extends AbstractAction {
// The default call back function name.
protected static final String J_CALLBACK = "feedBackUrlCallBack";
protected Event doExecute(final RequestContext context) {
HttpServletRequest request = WebUtils.getHttpServletRequest(context);
Event event = context.getCurrentEvent();
boolean isAjax = BooleanUtils.toBoolean(request.getParameter("isajax"));
if (!isAjax){ // 非 ajax/iframe 方式登录，返回当前 event.
return event;
}
boolean isLoginSuccess;
// Login Successful.
if ("success".equals(event.getId())){ //是否登录成功
final Service service = WebUtils.getService(context);
final String serviceTicket = WebUtils.getServiceTicketFromRequestScope(context);
if (service != null){ //设置登录成功之后跳转的地址
request.setAttribute("service", service.getId());
}
request.setAttribute("ticket", serviceTicket);
isLoginSuccess = true;
} else { // Login Fails..
isLoginSuccess = false;
}
boolean isFrame = BooleanUtils.toBoolean(request.getParameter("isframe"));
String callback = request.getParameter("callback");
if(StringUtils.isEmpty(callback)){ // 如果未转入 callback 参数，则采用默认 callback 函数名
callback = J_CALLBACK;
}
if(isFrame){ // 如果采用了 iframe ，则 concat 其 parent 。
callback = "parent.".concat(callback);
}
request.setAttribute("isFrame", isFrame);
request.setAttribute("callback", callback);
request.setAttribute("isLogin", isLoginSuccess);
return new Event(this, "local"); // 转入 ajaxLogin.jsp 页面
}
}

再定义一下 view 的页面地址，修改 default_views.properties，添加:

viewAjaxLoginView.(class)=org.springframework.web.servlet.view.JstlView
viewAjaxLoginView.url=/WEB-INF/view/jsp/custom/ui/ajaxLogin.jsp

再是 ajaxLogin.jsp 的代码，从 request attributes 中获取到 ST, Service 等参数信息:

查看文本打印 ?

<%@ page contentType="text/html; charset=UTF-8"%>
<html>
<head>
<title>正在登录....</title>
</head>
<body>
<script type="text/javascript">
<%
Boolean isFrame = (Boolean)request.getAttribute("isFrame");
Boolean isLogin = (Boolean)request.getAttribute("isLogin");
// 登录成功
if(isLogin){
if(isFrame){%>
//parent.location.replace('${service}?ticket=${ticket}')
<%} else{%>
location.replace('${service}?ticket=${ticket}')
<%}
}
%>
// 回调
${callback}({'login':${isLogin ? '"success"': '"false"'}, 'msg': ${isLogin ? '""': '"用户名或密码错误！"'}})
</script>
</body>
</html>

然后客户端登录页面login.jsp:

查看文本打印 ?

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www./TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Cas登录</title>
<script type="text/javascript" src="js/jquery.js"></script>
<script type="text/javascript" src="js/jquery.form.js"></script>
<script type="text/javascript">
$(document).ready(function(){
flushLoginTicket(); // 进入登录页，则获取login ticket，该函数在下面定义。
});
// 登录验证函数, 由 onsubmit 事件触发
var loginValidate = function(){
var msg;
if ($.trim($('#J_Username').val()).length == 0 ){
msg = "用户名不能为空。";
} else if ($.trim($('#J_Password').val()).length == 0 ){
msg = "密码不能为空。";
}
if (msg && msg.length > 0) {
$('#J_ErrorMsg').fadeOut().text(msg).fadeIn();
return false;
// Can't request the login ticket.
} else if ($('#J_LoginTicket').val().length == 0){
$('#J_ErrorMsg').text('服务器正忙，请稍后再试..');
return false;
} else {
// 验证成功后，动态创建用于提交登录的 iframe
$('body').append($('<iframe/>').attr({
style: "display:none;width:0;height:0",
id: "ssoLoginFrame",
name: "ssoLoginFrame",
src: "javascript:false;"
}));
return true;
}
}
// 登录处理回调函数，将由 iframe 中的页同自动回调
var feedBackUrlCallBack = function (result) {
customLoginCallBack(result);
deleteIFrame('#ssoLoginFrame');// 删除用完的iframe,但是一定不要在回调前删除，Firefox可能有问题的
};
// 自定义登录回调逻辑
var customLoginCallBack = function(result){
// 登录失败，显示错误信息
if (result.login == 'false'){
$('#J_ErrorMsg').fadeOut().text(result.msg).fadeIn();
// 重新刷新 login ticket
flushLoginTicket();
}else{
//该处定义登录成功后需要执行的操作,比如刷新DIV等
//......
alert("登陆成功");
}
}
var deleteIFrame = function (iframeName) {
var iframe = $(iframeName);
if (iframe) { // 删除用完的iframe，避免页面刷新或前进、后退时，重复执行该iframe的请求
iframe.remove()
}
};
// 由于一个 login ticket 只允许使用一次, 当每次登录需要调用该函数刷新 lt
var flushLoginTicket = function(){
var _services = 'service=' + encodeURIComponent('http://localhost/web/login.jsp');
var casUrl = 'http://localhost:8080/cas/login?'+_services+'&get-lt=true&n=' + new Date().getTime();
$.ajax({
type: "GET",
url: casUrl,
success: function(data){
var datadata = data.split('&');
$('#J_LoginTicket').val(data[0]);
$("#J_Execution").val(data[1]);
}
});
}
</script>
</head>
<body>
<form action="http://localhost:8080/cas/login" method="post" onsubmit="return loginValidate();" target="ssoLoginFrame">
<ul>
<li>
Url中的service参数为登录成功后返回的页面,因为我在ajaxLogin.jsp页面并没有设置使用iframe时跳转，所以看到的结果是页面没跳转,但是设置该参数还是很有必要的。比如当使用spring security时，service=http://localhost/web/j_spring_cas_security_check ，当登录成功时就会通过该URL对用户进行授权认证。
至此，整个开发就算完成，本人也是才开始学cas，该方法比较粗糙，但理解起来比较简单。