以下内容参考了 http://www.mkyong.com/spring-security/spring-security-form-login-example/
接上回，在前面的Hello World示例中，Spring Security为我们自动生成了默认登录页，对于大多数项目而言，如此简单的登录页并不能满足实际需求，接下来，我们看看如何自定义登录页
一、项目结构
与前一个示例相比较，只是多了一个css样式以及登录页login.jsp，这二个文件具体的内容如下：
1 @CHARSET "UTF-8";
2
3 .error {
4 padding: 15px;
5 margin-bottom: 20px;
6 border: 1px solid transparent;
7 border-radius: 4px;
8 color: #a94442;
9 background-color: #f2dede;
10 border-color: #ebccd1;
11 }
12
13 .msg {
14 padding: 15px;
15 margin-bottom: 20px;
16 border: 1px solid transparent;
17 border-radius: 4px;
18 color: #31708f;
19 background-color: #d9edf7;
20 border-color: #bce8f1;
21 }
22
23 #login-box {
24 width: 300px;
25 padding: 20px;
26 margin: 100px auto;
27 background: #fff;
28 -webkit-border-radius: 2px;
29 -moz-border-radius: 2px;
30 border: 1px solid #000;
31 }login.css
1 <%@ page language="java" contentType="text/html; charset=UTF-8"
2 pageEncoding="UTF-8"%>
3 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
4 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
5 <html>
6 <head>
7 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
8 <title>Login Page</title>
9 <link rel="Stylesheet" type="text/css" href="${pageContext.request.contextPath}/resources/css/login.css" />
10 </head>
11 <body onload='document.loginForm.username.focus();'>
12 <h1>Spring Security Custom Login Form (XML)</h1>
13
14 <div id="login-box">
15 <h3>Login with Username and Password</h3>
16 <c:if test="${not empty error}">
17 <div class="error">${error}</div>
18 </c:if>
19 <c:if test="${not empty msg}">
20 <div class="msg">${msg}</div>
21 </c:if>
22 <form name='loginForm'
23 action="<c:url value='j_spring_security_check' />" method='POST'>
24 <table>
25 <tr>
26 <td>User:</td>
27 <td><input type='text' name='username' value=''></td>
28 </tr>
29 <tr>
30 <td>Password:</td>
31 <td><input type='password' name='password' /></td>
32 </tr>
33 <tr>
34 <td colspan='2'><input name="submit" type="submit"
35 value="submit" /></td>
36 </tr>
37 </table>
38 <input type="hidden" name="${_csrf.parameterName}"
39 value="${_csrf.token}" />
40 </form>
41 </div>
42 </body>
43 </html>login.jsp
有几个地方解释一下：
第9行，css静态资源的引用方式，如果对Spring MVC不熟悉的人，可借此示例学习一下
15-20行，用了一个if标签来判断登录验证是否有错，如果验证失败，则显示错误信息，其中error,msg这二个变量，是从Controller里返回的信息（后面马上会讲到）
23行form表单的action地址留意一下，这个不能改，这是Spring Security的约定
38-39行的隐藏域_csrf，这是用来防止跨站提交攻击的，如果看不懂，可暂时无视。
二、Controller
1 package com.cnblogs.yjmyzz;
2
3 import org.springframework.stereotype.Controller;
4 import org.springframework.web.bind.annotation.RequestMapping;
5 import org.springframework.web.bind.annotation.RequestMethod;
6 import org.springframework.web.bind.annotation.RequestParam;
7 import org.springframework.web.servlet.ModelAndView;
8
9 @Controller10 public class HelloController {
11
12 @RequestMapping(value = { "/", "/welcome" }, method = RequestMethod.GET)
13 public ModelAndView welcome() {
14
15 ModelAndView model = new ModelAndView();
16 model.addObject("title", "Spring Security Custom Login Form");
17 model.addObject("message", "This is welcome page!");
18 model.setViewName("hello");
19 return model;
20
21 }
22
23 @RequestMapping(value = "/admin", method = RequestMethod.GET)
24 public ModelAndView admin() {
25
26 ModelAndView model = new ModelAndView();
27 model.addObject("title", "Spring Security Custom Login Form");
28 model.addObject("message", "This is protected page!");
29 model.setViewName("admin");
30
31 return model;
32
33 }
34
35 //新增加的Action方法，映射到
36 // 1. /login 登录页面的常规显示
37 // 2. /login?error 登录验证失败的展示
38 // 3. /login?logout 注销登录的处理
39 @RequestMapping(value = "/login", method = RequestMethod.GET)
40 public ModelAndView login(
41 @RequestParam(value = "error", required = false) String error,
42 @RequestParam(value = "logout", required = false) String logout) {
43
44 ModelAndView model = new ModelAndView();
45 if (error != null) {
46 model.addObject("error", "Invalid username and password!");
47 }
48
49 if (logout != null) {
50 model.addObject("msg", "You've been logged out successfully.");
51 }
52 model.setViewName("login");
53
54 return model;
55
56 }
57
58 }HelloController
增加了一个login方法，映射到登录的三种情况（常规显示，出错展示，注销登录）
三、spring-security.xml
1 <beans:beans xmlns="http://www.springframework.org/schema/security" 2 xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://www.springframework.org/schema/beans 4 http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 5 http://www.springframework.org/schema/security 6 http://www.springframework.org/schema/security/spring-security-3.2.xsd"> 7 8 <http auto-config="true"> 9 <intercept-url pattern="/admin" access="ROLE_USER" /> 10 <form-login login-page="/login" default-target-url="/welcome" 11 authentication-failure-url="/login?error" username-parameter="username" 12 password-parameter="password" /> 13 <logout logout-success-url="/login?logout" /> 14 <!-- enable csrf protection --> 15 <csrf /> 16 </http> 17 18 <authentication-manager> 19 <authentication-provider> 20 <user-service> 21 <user name="yjmyzz" password="123456" authorities="ROLE_USER" /> 22 </user-service> 23 </authentication-provider> 24 </authentication-manager> 25 26 </beans:beans>
spring-security.xml
注意8-16行的变化，一看即懂，就不多做解释了
运行效果：
登录页正常显示的截图
登录失败的截图
有兴趣的还可以看下对应的html源代码
防跨站提交攻击的_csrf隐藏域，会生成一个随机的类似guid字符串来做校验，以确定本次http post确实是从本页面发起的，这跟asp.net里mac ViewState的思路一致。
最后附示例源代码下载：SpringSecurity-CustomLoginForm-XML(0717).zip
随时随地看视频
