一、前言

      在上一篇http://blog.csdn.net/k10509806/archive/2011/04/28/6369131.aspx文章中，提到的MyUserDetailServiceImpl获取用户权限，在用户没有登陆的时候，Spring Security会让我们自动跳转到默认的登陆界面，但在实际应用绝大多数是用我们自己的登陆界面的，其中就包括一些我们自己的逻辑，比如验证码。所以本人又研究一下，终于摸清了一些如何配置自己的登陆界面的办法。在这里献丑了。

二、Spring Security的过滤器

      通过DEBUG可以看到Spring Security的Filter的顺序

Security filter chain: [
  ConcurrentSessionFilter
  SecurityContextPersistenceFilter
  LogoutFilter
  MyUsernamePasswordAuthenticationFilter
  RequestCacheAwareFilter
  SecurityContextHolderAwareRequestFilter
  RememberMeAuthenticationFilter
  AnonymousAuthenticationFilter
  SessionManagementFilter
  ExceptionTranslationFilter
  MySecurityFilter
  FilterSecurityInterceptor
]

Spring Security的登陆验证用的就是MyUsernamePasswordAuthenticationFilter，所以要实现我们自己的验证，可以写一个类并继承MyUsernamePasswordAuthenticationFilter类，重写attemptAuthentication方法。

三、applicationContext-Security.xml配置

<?xml version="1.0" encoding="UTF-8"?> <beans:beans xmlns="http://www.springframework.org/schema/security" xmlns:beans="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.1.xsd"> <debug/> <http pattern="/js/**" security="none"/> <http pattern="/resource/**" security="none"></http> <http pattern="/login.jsp" security="none"/> <http use-expressions="true" entry-point-ref="authenticationProcessingFilterEntryPoint"> <logout/> <!-- 实现免登陆验证 --> <remember-me /> <session-management invalid-session-url="/timeout.jsp"> <concurrency-control max-sessions="10" error-if-maximum-exceeded="true" /> </session-management> <custom-filter ref="loginFilter" position="FORM_LOGIN_FILTER" /> <custom-filter ref="securityFilter" before="FILTER_SECURITY_INTERCEPTOR"/> </http> <!-- 登录验证器 --> <beans:bean id="loginFilter" class="com.huaxin.security.MyUsernamePasswordAuthenticationFilter"> <!-- 处理登录的action --> <beans:property name="filterProcessesUrl" value="/j_spring_security_check"></beans:property> <!-- 验证成功后的处理--> <beans:property name="authenticationSuccessHandler" ref="loginLogAuthenticationSuccessHandler"></beans:property> <!-- 验证失败后的处理--> <beans:property name="authenticationFailureHandler" ref="simpleUrlAuthenticationFailureHandler"></beans:property> <beans:property name="authenticationManager" ref="myAuthenticationManager"></beans:property> <!-- 注入DAO为了查询相应的用户 --> <beans:property name="usersDao" ref="usersDao"></beans:property> </beans:bean> <beans:bean id="loginLogAuthenticationSuccessHandler" class="org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler"> <beans:property name="defaultTargetUrl" value="/index.jsp"></beans:property> </beans:bean> <beans:bean id="simpleUrlAuthenticationFailureHandler" class="org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler"> <!-- 可以配置相应的跳转方式。属性forwardToDestination为true采用forward false为sendRedirect --> <beans:property name="defaultFailureUrl" value="/login.jsp"></beans:property> </beans:bean> <!-- 认证过滤器 --> <beans:bean id="securityFilter" class="com.huaxin.security.MySecurityFilter"> <!-- 用户拥有的权限 --> <beans:property name="authenticationManager" ref="myAuthenticationManager" /> <!-- 用户是否拥有所请求资源的权限 --> <beans:property name="accessDecisionManager" ref="myAccessDecisionManager" /> <!-- 资源与权限对应关系 --> <beans:property name="securityMetadataSource" ref="mySecurityMetadataSource" /> </beans:bean> <!-- 实现了UserDetailsService的Bean --> <authentication-manager alias="myAuthenticationManager"> <authentication-provider user-service-ref="myUserDetailServiceImpl" /> </authentication-manager> <beans:bean id="myAccessDecisionManager" class="com.huaxin.security.MyAccessDecisionManager"></beans:bean> <beans:bean id="mySecurityMetadataSource" class="com.huaxin.security.MySecurityMetadataSource"> <beans:constructor-arg name="resourcesDao" ref="resourcesDao"></beans:constructor-arg> </beans:bean> <beans:bean id="myUserDetailServiceImpl" class="com.huaxin.security.MyUserDetailServiceImpl"> <beans:property name="usersDao" ref="usersDao"></beans:property> </beans:bean> <!-- 未登录的切入点 --> <beans:bean id="authenticationProcessingFilterEntryPoint" class="org.springframework.security.web.authentication.LoginUrlAuthenticationEntryPoint"> <beans:property name="loginFormUrl" value="/login.jsp"></beans:property> </beans:bean> </beans:beans>

这里特别要说明一下，我们的<http>标签不能配置auto-config，因为这样配置后，依然会采用Spring Security的Filter Chain会与下面我们配的custom-filter冲突，最好会抛异常。还有配置一个切入点entry-point-ref="authenticationProcessingFilterEntryPoint"，为了在未登陆的时候，跳转到哪个页面，不配也会抛异常。

 <custom-filter ref="loginFilter" position="FORM_LOGIN_FILTER"  /> position表示替换掉Spring Security原来默认的登陆验证Filter。

四、MyUsernamePasswordAuthenticationFilter

package com.huaxin.security; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.commons.lang.xwork.StringUtils; import org.springframework.security.authentication.AuthenticationServiceException; import org.springframework.security.authentication.UsernamePasswordAuthenticationToken; import org.springframework.security.core.Authentication; import org.springframework.security.core.AuthenticationException; import org.springframework.security.web.WebAttributes; import org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter; import com.huaxin.bean.Users; import com.huaxin.dao.UsersDao; /* * * UsernamePasswordAuthenticationFilter源码 attemptAuthentication this.getAuthenticationManager() ProviderManager.java authenticate(UsernamePasswordAuthenticationToken authRequest) AbstractUserDetailsAuthenticationProvider.java authenticate(Authentication authentication) P155 user = retrieveUser(username, (UsernamePasswordAuthenticationToken) authentication); DaoAuthenticationProvider.java P86 loadUserByUsername */ public class MyUsernamePasswordAuthenticationFilter extends UsernamePasswordAuthenticationFilter{ public static final String VALIDATE_CODE = "validateCode"; public static final String USERNAME = "username"; public static final String PASSWORD = "password"; private UsersDao usersDao; public UsersDao getUsersDao() { return usersDao; } public void setUsersDao(UsersDao usersDao) { this.usersDao = usersDao; } @Override public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException { if (!request.getMethod().equals("POST")) { throw new AuthenticationServiceException("Authentication method not supported: " + request.getMethod()); } //检测验证码 checkValidateCode(request); String username = obtainUsername(request); String password = obtainPassword(request); //验证用户账号与密码是否对应 username = username.trim(); Users users = this.usersDao.findByName(username); if(users == null || !users.getPassword().equals(password)) { /* 在我们配置的simpleUrlAuthenticationFailureHandler处理登录失败的处理类在这么一段 这样我们可以在登录失败后，向用户提供相应的信息。 if (forwardToDestination) { request.setAttribute(WebAttributes.AUTHENTICATION_EXCEPTION, exception); } else { HttpSession session = request.getSession(false); if (session != null || allowSessionCreation) { request.getSession().setAttribute(WebAttributes.AUTHENTICATION_EXCEPTION, exception); } } */ throw new AuthenticationServiceException("用户名或者密码错误！"); } //UsernamePasswordAuthenticationToken实现 Authentication UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(username, password); // Place the last username attempted into HttpSession for views // 允许子类设置详细属性 setDetails(request, authRequest); // 运行UserDetailsService的loadUserByUsername 再次封装Authentication return this.getAuthenticationManager().authenticate(authRequest); } protected void checkValidateCode(HttpServletRequest request) { HttpSession session = request.getSession(); String sessionValidateCode = obtainSessionValidateCode(session); //让上一次的验证码失效 session.setAttribute(VALIDATE_CODE, null); String validateCodeParameter = obtainValidateCodeParameter(request); if (StringUtils.isEmpty(validateCodeParameter) || !sessionValidateCode.equalsIgnoreCase(validateCodeParameter)) { throw new AuthenticationServiceException("验证码错误！"); } } private String obtainValidateCodeParameter(HttpServletRequest request) { Object obj = request.getParameter(VALIDATE_CODE); return null == obj ? "" : obj.toString(); } protected String obtainSessionValidateCode(HttpSession session) { Object obj = session.getAttribute(VALIDATE_CODE); return null == obj ? "" : obj.toString(); } @Override protected String obtainUsername(HttpServletRequest request) { Object obj = request.getParameter(USERNAME); return null == obj ? "" : obj.toString(); } @Override protected String obtainPassword(HttpServletRequest request) { Object obj = request.getParameter(PASSWORD); return null == obj ? "" : obj.toString(); } }

有时间，大家看看源码吧。

五、login.jsp

<body> <span style="color:red"><%=session.getAttribute(WebAttributes.AUTHENTICATION_EXCEPTION) %></span> <form action="j_spring_security_check" method="post"> Account：<Input name="username"/><br/> Password：<input name="password" type="password"/><br/> <input value="submit" type="submit"/> </form> </body>

六、完了，源码大家可以看下我上一篇文章http://blog.csdn.net/k10509806/archive/2011/04/28/6369131.aspx。