Spring Security 实战干货：登录成功后返回 JWT Token

1. 前言

欢迎阅读 Spring Security 实战干货系列文章，上一文我们实现了 JWT 工具。本篇我们将一起探讨如何将 JWT 与 Spring Security 结合起来，在认证成功后不再跳转到指定页面而是直接返回 JWT Token 。本文的**DEMO 可通过文末的方式获取**

2. 流程

JWT 适用于前后端分离。我们在登录成功后不在跳转到首页，将会直接返回 JWT Token 对（DEMO中为JwtTokenPair），登录失败后返回认证失败相关的信息。

3. 实现登录成功/失败返回逻辑

如果你看过 Spring Security 实战干货：玩转自定义登录将非常容易理解下面的做法。

3.1 AuthenticationSuccessHandler 返回 JWT Token

AuthenticationSuccessHandler 用于处理登录成功后的逻辑，我们编写实现并注入 Spring IoC 容器：

     /**
      * 处理登录成功后返回 JWT Token 对.
      *
      * @param jwtTokenGenerator the jwt token generator
      * @return the authentication success handler
      */
     @Bean
     public AuthenticationSuccessHandler authenticationSuccessHandler(JwtTokenGenerator jwtTokenGenerator) {
         return (request, response, authentication) -> {
             if (response.isCommitted()) {
                 log.debug("Response has already been committed");
                 return;
             }
             Map<String, Object> map = new HashMap<>(5);
             map.put("time", LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
             map.put("flag", "success_login");
             User principal = (User) authentication.getPrincipal();

             String username = principal.getUsername();
             Collection<GrantedAuthority> authorities = principal.getAuthorities();
             Set<String> roles = new HashSet<>();
             if (CollectionUtil.isNotEmpty(authorities)) {
                 for (GrantedAuthority authority : authorities) {
                     String roleName = authority.getAuthority();
                     roles.add(roleName);
                 }
             }

             JwtTokenPair jwtTokenPair = jwtTokenGenerator.jwtTokenPair(username, roles, null);

             map.put("access_token", jwtTokenPair.getAccessToken());
             map.put("refresh_token", jwtTokenPair.getRefreshToken());

             ResponseUtil.responseJsonWriter(response, RestBody.okData(map, "登录成功"));
         };
     }

3.2 AuthenticationFailureHandler 返回认证失败信息

AuthenticationFailureHandler 处理认证失败后的逻辑，前端根据此返回进行跳转处理逻辑，我们也实现它并注入 Spring IoC 容器：

     /**
      * 失败登录处理器 处理登录失败后的逻辑 登录失败返回信息 以此为依据跳转
      *
      * @return the authentication failure handler
      */
     @Bean
     public AuthenticationFailureHandler authenticationFailureHandler() {
         return (request, response, exception) -> {
             if (response.isCommitted()) {
                 log.debug("Response has already been committed");
                 return;
             }
             Map<String, Object> map = new HashMap<>(2);

             map.put("time", LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
             map.put("flag", "failure_login");
             ResponseUtil.responseJsonWriter(response, RestBody.build(HttpStatus.UNAUTHORIZED.value(), map, "认证失败","-9999"));
         };
     }

4. 配置

把上面写好的两个 Handler Bean 写入登录配置，相关片断如下，详情参见文末 DEMO：

 httpSecurity.formLogin().loginProcessingUrl(LOGIN_PROCESSING_URL).successHandler(authenticationSuccessHandler).failureHandler(authenticationFailureHandler)

5. 验证

我们依然通过 Spring Security 实战干货：玩转自定义登录一文中章节 6.4 测试 来运行。结果如下：

5.1 登录成功结果

 {
     "httpStatus": 200,
     "data": {
         "access_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJhbGwiLCJhdWQiOiJGZWxvcmRjbiIsInJvbGVzIjoiW10iLCJpc3MiOiJmZWxvcmQuY24iLCJleHAiOiIyMDE5LTExLTI3IDExOjMxOjMyIiwiaWF0IjoiMjAxOS0xMC0yOCAxMTozMTozMiIsImp0aSI6IjdmYTBlOWFiYjk5OTRjZGRhNGM5NjI4YzExNGM3YTk4In0.PvVsc8w10_0C5UIifJS1S5dEia5PQoVc_6wMfLAZOf574kt-VopHBVEp2zkjC1CNN3ltchy5rx6samaBDQvqWgoeFLXbRgNOa9Qhdf0wMLf-pUqoKRHuhBZV9HsvXSyQCFjZWlIguv4FSPZhbEff6D_8QUXmdWjlF_XEG2BPMr4",
         "refresh_token": "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJhbGwiLCJhdWQiOiJGZWxvcmRjbiIsInJvbGVzIjoiW10iLCJpc3MiOiJmZWxvcmQuY24iLCJleHAiOiIyMDIwLTAxLTI2IDExOjMxOjMyIiwiaWF0IjoiMjAxOS0xMC0yOCAxMTozMTozMiIsImp0aSI6IjdmYTBlOWFiYjk5OTRjZGRhNGM5NjI4YzExNGM3YTk4In0.Caj4AAothdUwZAFl8IjcAZmmXHgTt76z8trVG1sf_WHZucFVcHR8FWjShhITpArsQpmokP6GBTMsCvWDl08fUVZBpOWc1CdPUAIIEdArHCFzO64HXc_DLSyg9v0C-qYfxaTlf0npL5QxpBBr9sJcyzxZF3CnpfZpAxm8WZzXG6o",
         "time": "2019-10-28 11:32:11",
         "flag": "success_login"
     },
     "msg": "登录成功",
     "identifier": ""
 }

我们取 access_token 使用官网jwt.io 提供的解码功能进行解码如下：

Spring Security 实战干货：登录成功后返回 JWT Token

5.2 登录失败结果

 {
     "httpStatus": 401,
     "data": {
         "time": "2019-10-28 12:54:10",
         "flag": "failure_login"
     },
     "msg": "认证失败",
     "identifier": "-9999"
 }