搞懂单点登录SSO，基于SpringBoot+JWT实现单点登录解决方案

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
    <exclusions>
        <exclusion>
            <groupId>io.lettuce</groupId>
            <artifactId>lettuce-core</artifactId>
        </exclusion>
    </exclusions>
</dependency>

<!-- SpringBoot集成thymeleaf模板 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>

<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
</dependency>

<dependency>
    <groupId>redis.clients</groupId>
    <artifactId>jedis</artifactId>
</dependency>

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.83</version>
</dependency>
<dependency>
    <groupId>com.auth0</groupId>
    <artifactId>java-jwt</artifactId>
    <version>3.10.3</version>
</dependency>

/**
 * 类功能简述：
 * 类功能详述：
 *
 * @author weiz
 */
public class JwtUtil {

    /**
     * Description: 生成一个jwt字符串
     *
     * @param name    用户名
     * @param secret  秘钥
     * @param timeOut 超时时间（单位s）
     * @return java.lang.String
     * @author weiz
     */
    public static String encode(String name, String secret, long timeOut) {
        Algorithm algorithm = Algorithm.HMAC256(secret);
        String token = JWT.create()
                //设置过期时间为一个小时
                .withExpiresAt(new Date(System.currentTimeMillis() + timeOut))
                //设置负载
                .withClaim("name", name)
                .sign(algorithm);
        return token;
    }

    /**
     * Description: 解密jwt
     *
     * @param token  token
     * @param secret secret
     * @return java.util.Map<java.lang.String                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               ,                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               com.auth0.jwt.interfaces.Claim>
     * @author weiz
     */
    public static Map<String, Claim> decode(String token, String secret) {
        if (token == null || token.length() == 0) {
            throw new CustomException("token为空:" + token);
        }
        Algorithm algorithm = Algorithm.HMAC256(secret);
        JWTVerifier jwtVerifier = JWT.require(algorithm).build();
        DecodedJWT decodedJWT = jwtVerifier.verify(token);
        return decodedJWT.getClaims();
    }
}

/**
 * 类功能简述：
 * 类功能详述：
 *
 * @author weiz
 */
@Controller
@RequestMapping("/sso")
public class AuthController {

    private JwtService service;

    @Autowired
    public AuthController(JwtService service) {
        this.service = service;
    }

    @RequestMapping({"/","/index"})
    public String index(){
        return "index";
    }

    @RequestMapping("/login")
    public String login(){
        return "login";
    }

    @RequestMapping(value = "/login",method = RequestMethod.POST)
    @ResponseBody
    public ReturnResult login(@RequestBody User user) {
        String token = service.login(user);
        return ReturnResult.successResult(token);
    }

    @RequestMapping("/checkJwt")
    @ResponseBody
    public ReturnResult checkJwt(String token) {
        return ReturnResult.successResult(service.checkJwt(token));
    }

    @RequestMapping("/refreshJwt")
    @ResponseBody
    public ReturnResult refreshJwt(String token){
        return ReturnResult.successResult(service.refreshJwt(token));
    }

    @RequestMapping("/inValid")
    @ResponseBody
    public ReturnResult inValid(String token) {
        service.inValid(token);
        return ReturnResult.successResult(null);
    }
}

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <!-- SpringBoot集成thymeleaf模板 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

        <dependency>
            <groupId>com.squareup.okhttp3</groupId>
            <artifactId>okhttp</artifactId>
            <version>3.14.9</version>
        </dependency>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.83</version>
        </dependency>

/**
 * 类功能简述：
 * 类功能详述：
 *
 * @author weiz
 */
@Component
@WebFilter(urlPatterns = "/**", filterName = "loginFilter")
public class LoginFilter implements Filter {

    private Logger logger = LoggerFactory.getLogger(this.getClass());

    @Value("${sso_server}")
    private String serverHost;

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void destroy() {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;
        String token = httpServletRequest.getParameter("token");
        if (this.check(token)) {
            filterChain.doFilter(servletRequest, servletResponse);
        } else {
            HttpServletResponse response = (HttpServletResponse) servletResponse;
            String redirect = serverHost + "/login?redirect=" + httpServletRequest.getRequestURL();
            //response.setContentType("application/json;charset=utf-8");
            //response.setCharacterEncoding("utf-8");
            //response.getWriter().write(JSON.toJSONString(new ReturnEntity(-1, "未登录", null)));
            response.sendRedirect(redirect);
        }
    }

    private boolean check(String jwt) {
        try {
            if (jwt == null || jwt.trim().length() == 0) {
                return false;
            }
            JSONObject object = HttpClient.get(serverHost + "/checkJwt?token=" + jwt);
            return object.getBoolean("data");
        } catch (Exception e) {
            logger.error("向认证中心请求失败", e);
            return false;
        }

    }
}

/**
 * 类功能简述：
 * 类功能详述：
 *
 * @author weiz
 */
@Controller
public class IndexController {

    @Value("${sso_server}")
    private String serverHost;

    @RequestMapping({"/","/index"})
    public String index() {
        return "index";
    }

    @RequestMapping("/test")
    @ResponseBody
    public ReturnEntity test() {
        return new ReturnEntity(1, "通过验证", null);
    }

    @RequestMapping("/logout")
    public void logout(HttpServletRequest request, HttpServletResponse response,String token) throws Exception {
        HttpClient.get(serverHost + "/inValid?token=" + token);
        String requestHost = request.getScheme() +"://"+ request.getServerName() + ":"+request.getServerPort() +"/";
        String redirect = serverHost + "/login?redirect=" + requestHost;
        System.out.println(redirect);
        response.sendRedirect(redirect);
    }
}