功能：登录时的“记住我”功能
原理：
rememberMeAuthenticationFilter在security过滤器链中的位置，在请求走认证流程是，当前边的filter都不通过时，会走rememberMeAuthenticationFilter
代码：
html：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>自定义登录页面</title>
</head>
<body>
<h2>自定义登录页面</h2>
<form action="/authentication/form" method="POST">
<table>
<tr>
<td>用户名：</td>
<td><input type="text" name="username"></td>
</tr>
<tr>
<td>密码：</td>
<td><input type="password" name="password"></td>
</tr>
<tr>
<td>图形验证码：</td>
<td>
<input type="text" name="imageCode">
<img src="/code/image?width=200" alt="">
</td>
</tr>
<tr>
<td colspan="2"><!-- 其中的name值 remember-me 是固定不变的，security默认 -->
<input type="checkbox" name="remember-me" value="true">记住我
</td>
</tr>
<tr>
<td colspan="2">
<button type="submit">登录</button>
</td>
</tr>
</table>
</form>
</body>
</html>
security配置：
@Autowired private DataSource dataSource;//datasource 用的是springboot默认的application.yml中的配置 @Autowired private UserDetailsService userDetailsService; @Bean public PersistentTokenRepository persistentTokenRepository() { JdbcTokenRepositoryImpl jdbcTokenRepository = new JdbcTokenRepositoryImpl(); jdbcTokenRepository.setDataSource(dataSource); //自动创建相关的token表 jdbcTokenRepository.setCreateTableOnStartup(true); return jdbcTokenRepository; } @Override protected void configure(HttpSecurity http) throws Exception { //用户可自定义、亦可以使用mysecurity默认的登录页 String loginPage = securityProperties.getBrowser().getLoginPage(); http.formLogin() .loginPage("/authentication/require").loginProcessingUrl("/authentication/form") .successHandler(custAuthenticationSuccessHandler) .failureHandler(custAuthenticationFailerHandler) .and() .rememberMe() .tokenRepository(persistentTokenRepository())//用于将token信息存储到数据库中 .tokenValiditySeconds(3600) .userDetailsService(userDetailsService)//用于登录 .and() .authorizeRequests() .antMatchers("/authentication/require", loginPage, "/code/image").permitAll() .anyRequest() .authenticated(); http.csrf().disable();//暂时设为disable 防止跨站请求伪造的功能 }
启动项目：（因配置了dbcTokenRepository.setCreateTableOnStartup(true) 所以会自动创建下表用于存储用户token信息）
页面：点击记住我后登录
登录成功之后会在persistent_login表中插入一条数据：
重启项目，直接访问资源路径：
http://localhost:8080/user/1
不需要跳转到登录页面，直接返回具体信息
源码：
UserNamePasswordAuthenticationFilter.class文件中的attempAuthentication方法
public Authentication attemptAuthentication(HttpServletRequest request, HttpServletResponse response) throws AuthenticationException { if (this.postOnly && !request.getMethod().equals("POST")) { throw new AuthenticationServiceException("Authentication method not supported: " + request.getMethod()); } else { String username = this.obtainUsername(request); String password = this.obtainPassword(request); if (username == null) { username = ""; } if (password == null) { password = ""; } username = username.trim(); UsernamePasswordAuthenticationToken authRequest = new UsernamePasswordAuthenticationToken(username, password); this.setDetails(request, authRequest); return this.getAuthenticationManager().authenticate(authRequest); } }
查看其父类：
AbstractAuthenticationProcessingFilter类，this.attempAuthentication方法使用的是子类方法，也就是usernamepasswordauthenticationFilter类中的方法（上边的）
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest)req; HttpServletResponse response = (HttpServletResponse)res; if (!this.requiresAuthentication(request, response)) { chain.doFilter(request, response); } else { if (this.logger.isDebugEnabled()) { this.logger.debug("Request is to process authentication"); } Authentication authResult; try { authResult = this.attemptAuthentication(request, response); if (authResult == null) { return; } this.sessionStrategy.onAuthentication(authResult, request, response); } catch (InternalAuthenticationServiceException var8) { this.logger.error("An internal error occurred while trying to authenticate the user.", var8); this.unsuccessfulAuthentication(request, response, var8); return; } catch (AuthenticationException var9) { this.unsuccessfulAuthentication(request, response, var9); return; } if (this.continueChainBeforeSuccessfulAuthentication) { chain.doFilter(request, response); } this.successfulAuthentication(request, response, chain, authResult); } }
attempauthentication方法执行完之后，回到successfulAuthentication方法（也是AbstractAuthenticationProcessingFilter类），会有remberMeService类
protected void successfulAuthentication(HttpServletRequest request, HttpServletResponse response, FilterChain chain, Authentication authResult) throws IOException, ServletException { if (this.logger.isDebugEnabled()) { this.logger.debug("Authentication success. Updating SecurityContextHolder to contain: " + authResult); } SecurityContextHolder.getContext().setAuthentication(authResult); this.rememberMeServices.loginSuccess(request, response, authResult); if (this.eventPublisher != null) { this.eventPublisher.publishEvent(new InteractiveAuthenticationSuccessEvent(authResult, this.getClass())); } this.successHandler.onAuthenticationSuccess(request, response, authResult); }
loginSuccess方法会进入AbstractRememberMeService抽象类中：
public final void loginSuccess(HttpServletRequest request, HttpServletResponse response, Authentication successfulAuthentication) { if (!this.rememberMeRequested(request, this.parameter)) { this.logger.debug("Remember-me login not requested."); } else { this.onLoginSuccess(request, response, successfulAuthentication); } }
onLoginSuccess方法会进入PersistentTokenBaseRememberMeService类中（AbstractRememberMEService的子类）
protected void onLoginSuccess(HttpServletRequest request, HttpServletResponse response, Authentication successfulAuthentication) { String username = successfulAuthentication.getName(); this.logger.debug("Creating new persistent login for user " + username); PersistentRememberMeToken persistentToken = new PersistentRememberMeToken(username, this.generateSeriesData(), this.generateTokenData(), new Date()); try { this.tokenRepository.createNewToken(persistentToken); this.addCookie(persistentToken, request, response); } catch (Exception var7) { this.logger.error("Failed to save persistent token ", var7); } }
这里的这个tokenRepository就是在配置文件中定义的persistentTokenRepository，addCookie方法会将token写到浏览器的cookie中，等下次请求的时候回自动带着token
下一次访问会进入到RememberAuthenticationFilter过滤器中：
public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest)req; HttpServletResponse response = (HttpServletResponse)res;
//判断context中是否已经有了一个认证的Authentication对象 if (SecurityContextHolder.getContext().getAuthentication() == null) {
//是否可以自动登录 Authentication rememberMeAuth = this.rememberMeServices.autoLogin(request, response); if (rememberMeAuth != null) { try { rememberMeAuth = this.authenticationManager.authenticate(rememberMeAuth); //将一个已经认证的authentication对象放到context中
SecurityContextHolder.getContext().setAuthentication(rememberMeAuth); this.onSuccessfulAuthentication(request, response, rememberMeAuth); if (this.logger.isDebugEnabled()) { this.logger.debug("SecurityContextHolder populated with remember-me token: '" + SecurityContextHolder.getContext().getAuthentication() + "'"); } if (this.eventPublisher != null) { this.eventPublisher.publishEvent(new InteractiveAuthenticationSuccessEvent(SecurityContextHolder.getContext().getAuthentication(), this.getClass())); } if (this.successHandler != null) { this.successHandler.onAuthenticationSuccess(request, response, rememberMeAuth); return; } } catch (AuthenticationException var8) { if (this.logger.isDebugEnabled()) { this.logger.debug("SecurityContextHolder not populated with remember-me token, as AuthenticationManager rejected Authentication returned by RememberMeServices: '" + rememberMeAuth + "'; invalidating remember-me token", var8); } this.rememberMeServices.loginFail(request, response); this.onUnsuccessfulAuthentication(request, response, var8); } } chain.doFilter(request, response); } else { if (this.logger.isDebugEnabled()) { this.logger.debug("SecurityContextHolder not populated with remember-me token, as it already contained: '" + SecurityContextHolder.getContext().getAuthentication() + "'"); } chain.doFilter(request, response); } }
autoLogin方法会进入到AbstractRememberMeService抽象类中：
public final Authentication autoLogin(HttpServletRequest request, HttpServletResponse response) { String rememberMeCookie = this.extractRememberMeCookie(request); if (rememberMeCookie == null) { return null; } else { this.logger.debug("Remember-me cookie detected"); if (rememberMeCookie.length() == 0) { this.logger.debug("Cookie was empty"); this.cancelCookie(request, response); return null; } else { UserDetails user = null; try { String[] cookieTokens = this.decodeCookie(rememberMeCookie); user = this.processAutoLoginCookie(cookieTokens, request, response); this.userDetailsChecker.check(user); this.logger.debug("Remember-me cookie accepted"); return this.createSuccessfulAuthentication(request, user); } catch (CookieTheftException var6) { 。。。。、。。。this.cancelCookie(request, response); return null; } } }
processAutoLoginCookie方法会走实现类PersistentTokenBasedRememberMeServices类中的方法：
protected UserDetails processAutoLoginCookie(String[] cookieTokens, HttpServletRequest request, HttpServletResponse response) { if (cookieTokens.length != 2) { throw new InvalidCookieException("Cookie token did not contain 2 tokens, but contained '" + Arrays.asList(cookieTokens) + "'"); } else { String presentedSeries = cookieTokens[0]; String presentedToken = cookieTokens[1]; PersistentRememberMeToken token = this.tokenRepository.getTokenForSeries(presentedSeries); if (token == null) { throw new RememberMeAuthenticationException("No persistent token found for series id: " + presentedSeries); } else if (!presentedToken.equals(token.getTokenValue())) { this.tokenRepository.removeUserTokens(token.getUsername()); throw new CookieTheftException(this.messages.getMessage("PersistentTokenBasedRememberMeServices.cookieStolen", "Invalid remember-me token (Series/token) mismatch. Implies previous cookie theft attack.")); } else if (token.getDate().getTime() + (long)this.getTokenValiditySeconds() * 1000L < System.currentTimeMillis()) { throw new RememberMeAuthenticationException("Remember-me login has expired"); } else { if (this.logger.isDebugEnabled()) { this.logger.debug("Refreshing persistent login token for user '" + token.getUsername() + "', series '" + token.getSeries() + "'"); } PersistentRememberMeToken newToken = new PersistentRememberMeToken(token.getUsername(), token.getSeries(), this.generateTokenData(), new Date()); try { this.tokenRepository.updateToken(newToken.getSeries(), newToken.getTokenValue(), newToken.getDate()); this.addCookie(newToken, request, response); } catch (Exception var9) { this.logger.error("Failed to update token: ", var9); throw new RememberMeAuthenticationException("Autologin failed due to data access problem"); } return this.getUserDetailsService().loadUserByUsername(token.getUsername()); } } }