JWT实现单点登录

落日映苍穹つ 2024-02-20 13:08 14阅读 0赞

#### 目录 ####

*  JWT单点登录
 *   *  1、表结构
     *  2、依赖
     *  3、实体
     *  4、JwtTokenUtil
     *  5、WebContextUtil
     *  6、AuthenticationInterceptor(token解析)
     *  7、JwtIgnore
     *  8、WebMvc配置
     *  9、UesrService
     *  10、UserController
     *  11、ExceptionController(全局异常处理)
     *  12、测试

## JWT单点登录 ##

### 1、表结构 ###

CREATE TABLE `user` (
      `id` int(11) unsigned NOT NULL AUTO_INCREMENT COMMENT '主键，用户ID',
      `username` varchar(255) NOT NULL COMMENT '用户名',
      `password` varchar(255) NOT NULL COMMENT '密码',
      `gender` int(1) DEFAULT NULL COMMENT '性别：0男，1女',
      `create_time` datetime NOT NULL COMMENT '创建时间',
      `update_time` datetime DEFAULT NULL COMMENT '更新时间',
      PRIMARY KEY (`id`)
    ) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4;
    
    
    INSERT INTO `user` VALUES (1, 'admin', '123456', 1, '2023-11-03 12:14:16', NULL);
    INSERT INTO `user` VALUES (2, 'test', '123456', 0, '2023-11-07 12:14:41', NULL);

### 2、依赖 ###

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.4.1</version>
        <relativePath/>
    </parent>
    
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
    
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.39</version>
        </dependency>
    
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.0</version>
        </dependency>
    
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.6.5</version>
        </dependency>
    
        
        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.9.1</version>
        </dependency>
    </dependencies>

### 3、实体 ###

User：用户实体

@Data
    public class User {
        
        private Long id;
        private String username;
        private String password;
        private Integer gender;
        private Date createTime;
        private Date updateTime;
    }

UserToken：token中存储的用户信息。因为token可以被解码，所以不要有敏感信息。

@Data
    public class UserToken implements Serializable {
        
        private Long id;
        private String username;
        private Integer gender;
    }

### 4、JwtTokenUtil ###

用于生成和解析token。

public class JwtTokenUtil {
        
        //定义token返回头部
        public static final String AUTH_HEADER_KEY = "Authorization";
    
        //token前缀
        public static final String TOKEN_PREFIX = "Bearer ";
    
        //签名密钥
        public static final String SECRET = "q3t6w9z$C&F)J@NcQfTjWnZr4u7x";
    
        //有效期默认为 2hour
        public static final Long EXPIRATION_TIME = 1000L*60*60*2;
    
        /**
         * 创建Token
         * @param content
         * @return
         */
        public static String createToken(String content) {
        
            return TOKEN_PREFIX + Jwts.builder()
                    .setSubject(content)
                    .setExpiration(new Date(System.currentTimeMillis() + EXPIRATION_TIME))
                    .signWith(SignatureAlgorithm.HS256, SECRET)
                    .compact();
        }
    
        /**
         * 校验token
         * @param token
         * @return
         * @throws Exception
         */
        public static String verifyToken(String token) throws Exception {
        
            try {
        
                return Jwts.parser()
                        .setSigningKey(SECRET)
                        .parseClaimsJws(token.replace(TOKEN_PREFIX, ""))
                        .getBody()
                        .getSubject();
    
            } catch (ExpiredJwtException e) {
        
                throw new Exception("token已失效，请重新登录", e);
            } catch (SignatureException e) {
        
                throw new Exception("token验证失败!", e);
            }
        }
    }

### 5、WebContextUtil ###

ThreadLocal缓存已经登录的用户。

public class WebContextUtil {
        
    
        //本地线程缓存token
        private static ThreadLocal<String> local = new ThreadLocal<>();
    
        /**
         * 设置token
         * @param content
         */
        public static void setUserToken(String content) {
        
            removeUserToken();
            local.set(content);
        }
    
        /**
         * 获取token信息
         * @return
         */
        public static UserToken getUserToken() {
        
            if (local.get() != null) {
        
                UserToken userToken = JSONUtil.toBean(local.get(), UserToken.class);
                return userToken;
            }
            return null;
        }
    
        /**
         * 删除token信息
         */
        public static void removeUserToken() {
        
            if (local.get() != null) {
        
                local.remove();
            }
        }
    }

### 6、AuthenticationInterceptor(token解析) ###

public class AuthenticationInterceptor implements HandlerInterceptor {
        
    
        /**
         * handler参数：可以是HandlerAdapter存在的任何类型。最常用的是利用HandlerMethod的RequestMappingHandlerAdapter。
         * 它可以是一个常规类、一个servlet，甚至是一个函数（当使用函数方法时）。
         * Spring Web Services还有一个实现以及Spring Integration。
         * Spring本身将支持：
         * HandlerMethod
         * HandlerFunction
         * Conroller
         * Servlet
         * HttpRequestHandler
         * WsdlDefinition (Spring Web Services)
         * XsdDefinition (Spring Web Services)
         */
        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        
            //从http请求头中获取token
            String token = request.getHeader(JwtTokenUtil.AUTH_HEADER_KEY);
            //如果不是映射到方法，放行(可能是请求静态资源等)
            if (!(handler instanceof HandlerMethod)) {
        
                return true;
            }
            //如果是方法探测，放行
            if (HttpMethod.OPTIONS.equals(request.getMethod())) {
        
                response.setStatus(HttpServletResponse.SC_OK);
                return true;
            }
            //如果方法有JwtIgnore注解，放行
            HandlerMethod handlerMethod = (HandlerMethod) handler;
            Method method = handlerMethod.getMethod();
            if (method.isAnnotationPresent(JwtIgnore.class)) {
        
                JwtIgnore jwtIgnore = method.getAnnotation(JwtIgnore.class);
                if (jwtIgnore.value()) {
        
                    return true;
                }
            }
            if (StrUtil.isBlank(token)) {
        
                throw new Exception("token为空，鉴权失败！");
            }
            //验证token
            String userToken = JwtTokenUtil.verifyToken(token);
            //放入本地缓存
            WebContextUtil.setUserToken(userToken);
            return true;
        }
    
        @Override
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        
            //方法结束后，移除缓存的token
            WebContextUtil.removeUserToken();
        }
    }

### 7、JwtIgnore ###

自定义注解，用于排除指定方法的token检验。

@Target({
        ElementType.METHOD, ElementType.TYPE})
    @Retention(RetentionPolicy.RUNTIME)
    public @interface JwtIgnore {
        
        boolean value() default true;
    }

### 8、WebMvc配置 ###

@Configuration
    public class GlobalWebMvcConfig implements WebMvcConfigurer {
        
    
        /**
         * 跨域配置
         * @param registry
         */
        @Override
        public void addCorsMappings(CorsRegistry registry) {
        
            // 添加映射路径
            registry.addMapping("/**")
                    // 放行哪些原始域
                    .allowedOriginPatterns("*")
                    // 是否发送Cookie信息
                    .allowCredentials(true)
                    // 放行哪些原始域(请求方式)
                    .allowedMethods("*")
                    // 放行哪些原始域(头部信息)
                    .allowedHeaders("*")
                    // 暴露哪些头部信息（因为跨域访问默认不能获取全部头部信息）
                    .exposedHeaders("Server","Content-Length", "Authorization", "Access-Token", "Access-Control-Allow-Origin","Access-Control-Allow-Credentials");
        }
    
        @Override
        public void addInterceptors(InterceptorRegistry registry) {
        
            //token拦截器
            registry.addInterceptor(new AuthenticationInterceptor())
                    .addPathPatterns("/**")
                    .excludePathPatterns("/static/**");
        }
    }

### 9、UesrService ###

@Service
    public class UserService {
        
    
        @Autowired
        private UserMapper userMapper;
    
        public String login(String username, String password) throws Exception {
        
            if (StrUtil.isBlank(username) || StrUtil.isBlank(password)) {
        
                throw new Exception("用户名或密码为空!");
            }
            User user = getUserByName(username);
            if (!password.equals(user.getPassword())) {
        
                throw new Exception("密码错误!");
            }
            //创建token
            UserToken userToken = BeanUtil.copyProperties(user, UserToken.class);
            String token = JwtTokenUtil.createToken(JSONUtil.toJsonStr(userToken));
            return token;
        }
    
    
        public User getUserByName(String username) {
        
            return userMapper.getUserByName(username);
        }
    }

### 10、UserController ###

@RestController
    public class UserController {
        
    
        @Autowired
        private UserService userService;
    
    
        @JwtIgnore
        @PostMapping("/login")
        public Map<String, Object> login(@RequestParam("username")String username, @RequestParam("password")String password) throws Exception {
        
            Map<String, Object> result = new HashMap<>();
            String token = userService.login(username, password);
            result.put("token", token);
            return result;
        }
    
    
        @GetMapping("/test")
        public Map<String, Object> test() {
        
            Map<String, Object> result = new HashMap<>();
            result.put("msg", "success");
            result.put("data", WebContextUtil.getUserToken());
            return result;
        }
    
    }

### 11、ExceptionController(全局异常处理) ###

@ControllerAdvice
    public class ExceptionController {
        
    
        @ResponseBody
        @ExceptionHandler(Exception.class)
        public Map<String, Object> handleException(Exception e) {
        
            Map<String, Object> map = new HashMap<>();
            map.put("code", 401);
            map.put("message", e.getMessage());
            return map;
        }
    }

### 12、测试 ###

**未登录直接访问：**  
![在这里插入图片描述][8e452300b74149dfb439ffdd54c0e96c.png]

**登录：**  
![在这里插入图片描述][0e1f96c414bb4ffeae864ad9d6669ab4.png]

**登录后访问接口：**  
![在这里插入图片描述][e70f8c3b76854454bbf6a3a4df4fed3f.png]

**访问静态资源：**  
![在这里插入图片描述][0dcaa2a7ae464f8b9d4d5b5ca5b66fcd.png]

[8e452300b74149dfb439ffdd54c0e96c.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/20/a7a7194459284b71842a4f33616de59d.png
[0e1f96c414bb4ffeae864ad9d6669ab4.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/20/a0c520118f524e1c99697b29993e7983.png
[e70f8c3b76854454bbf6a3a4df4fed3f.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/20/013fb98f7f794243bee687cffea3ad29.png
[0dcaa2a7ae464f8b9d4d5b5ca5b66fcd.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/20/df7ec5a9677b4fc5a852c9235dfd1a3b.png