1.新增依賴

        <dependency>
            <groupId>com.auth0</groupId>
            <artifactId>java-jwt</artifactId>
            <version>3.4.0</version>
        </dependency>

2.新增登入介面,返回前端token

@ApiOperation(value = "使用者登入")
    @PassToken
    @PostMapping(value 
 
= "/login")
    @ResponseBody
    public Object login(@RequestParam(name = "id") @ApiParam(value = "使用者id",required = true) String id,
                        @RequestParam(name = "password") @ApiParam(value = "使用者密碼",required = true)String password) {

        ValueOperations<String, Object> operations = redisTemplate.opsForValue();
        User user 
 
= userService.getUser(id, password);
        if(user==null){
            return new XPFBadRequestException("使用者不存在");
        }
        String token=getToken(user);
//        operations.set(user.getId(), token, 24*60*60, TimeUnit.SECONDS);
        return new XPFSingleResponse(token);
    }

    public String getToken(User user) {
        String token
 
="";
        token= JWT.create().withAudience(user.getId())
                .sign(Algorithm.HMAC256(user.getPassword()));
        return token;
    }

3.新增需要標誌需要登入的註解

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



@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface UserLoginToken {
    boolean required() default false;
}

4.新增HandlerInterceptor攔截器

@Component
public class AuthenticationInterceptor implements HandlerInterceptor {
    public AuthenticationInterceptor() {
        System.out.println("註冊攔截器");
    }

    @Resource
    private RedisTemplate<String, Object> redisTemplate;

    @Resource
    private UserService userService;
    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {


        httpServletResponse.addHeader("Access-Control-Allow-Origin", "*");
        httpServletResponse.addHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
        httpServletResponse.addHeader("Access-Control-Allow-Headers",
                "Content-Type,X-Requested-With,accept,Origin,Access-Control-Request-Method,Access-Control-Request-Headers,token,showName,phoneNum");



        String token = httpServletRequest.getHeader("token");// 從 http 請求頭中取出 token
        String id = httpServletRequest.getHeader("keyId");// 從 http 請求頭中取出 keyid
        // 如果不是對映到方法直接通過
        if (!(object instanceof HandlerMethod)) {
            return true;
        }


        HandlerMethod handlerMethod = (HandlerMethod) object;
        Method method = handlerMethod.getMethod();
        //檢查是否有passtoken註釋，有則跳過認證
        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }
        //檢查有沒有需要使用者許可權的註解
        if (method.isAnnotationPresent(UserLoginToken.class)) {
            UserLoginToken userLoginToken = method.getAnnotation(UserLoginToken.class);


            if (userLoginToken.required()) {
                // 執行認證
                if (token == null) {
                    throw new RuntimeException("無token，請重新登入");
                }
                // 獲取 token 中的 user id
                String userId;
                try {
                    userId = JWT.decode(token).getAudience().get(0);
                } catch (JWTDecodeException j) {
                    throw new RuntimeException("401");
                }


                System.out.println("userId=="+userId);
                User user = userService.getUserById(userId);
                if (user == null) {
                    throw new RuntimeException("使用者不存在，請重新登入");
                }
                // 驗證 token
                JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(user.getPassword())).build();
                try {
                    jwtVerifier.verify(token);
                } catch (JWTVerificationException e) {
                    throw new RuntimeException("401");
                }
                return true;
            }
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest,
                           HttpServletResponse httpServletResponse,
                           Object o, ModelAndView modelAndView) throws Exception {

    }
    /*
     * 整個請求處理完畢回撥方法,該方法也是需要當前對應的Interceptor的preHandle()的返回值為true時才會執行，
     * 也就是在DispatcherServlet渲染了對應的檢視之後執行。用於進行資源清理。整個請求處理完畢回撥方法。
     * 如效能監控中我們可以在此記錄結束時間並輸出消耗時間，還可以進行一些資源清理，類似於try-catch-finally中的finally，但僅呼叫處理器執行鏈中*/

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest,
                                HttpServletResponse httpServletResponse,
                                Object o, Exception e) throws Exception {
    }
}

4.1所有的攔截器的perHandler都是先執行的 和過濾器不同

5.為springmvc新增攔截器,和攔截規則

@Configuration
public class ApiConfig extends WebMvcConfigurationSupport {

    @Autowired
    private AuthenticationInterceptor authenticationInterceptor;

    @Override
    protected void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(this.authenticationInterceptor).addPathPatterns("/**");
        super.addInterceptors(registry);
    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {

        registry.addResourceHandler("swagger-ui.html")
                .addResourceLocations("classpath:/META-INF/resources/");

        registry.addResourceHandler("/webjars/**")
                .addResourceLocations("classpath:/META-INF/resources/webjars/");

    }
}