@Aspect
@Component
@Slf4j
publicclass RateLimitAspect {
    
    @Autowired
    private StringRedisTemplate redisTemplate;
    
    @Around("@annotation(rateLimit)")
    public Object around(ProceedingJoinPoint pjp, RateLimit rateLimit) throws Throwable {
        // 獲取請(qǐng)求的方法名
        String methodName = pjp.getSignature().getName();
        // 獲取請(qǐng)求的類名
        String className = pjp.getTarget().getClass().getName();
        
        // 組合限流 key
        String limitKey = getLimitKey(pjp, rateLimit, methodName, className);
        
        // 獲取限流參數(shù)
        int time = rateLimit.time();
        int count = rateLimit.count();
        
        // 執(zhí)行限流邏輯
        boolean limited = isLimited(limitKey, time, count);
        if (limited) {
            thrownew RuntimeException(rateLimit.message());
        }
        
        // 執(zhí)行目標(biāo)方法
        return pjp.proceed();
    }
    
    private String getLimitKey(ProceedingJoinPoint pjp, RateLimit rateLimit, String methodName, String className) {
        // 獲取用戶自定義的 key
        String key = rateLimit.key();
        
        if (StringUtils.hasText(key)) {
            // 支持 SpEL 表達(dá)式解析
            StandardEvaluationContext context = new StandardEvaluationContext();
            MethodSignature signature = (MethodSignature) pjp.getSignature();
            String[] parameterNames = signature.getParameterNames();
            Object[] args = pjp.getArgs();
            
            for (int i = 0; i < parameterNames.length; i++) {
                context.setVariable(parameterNames[i], args[i]);
            }
            
            ExpressionParser parser = new SpelExpressionParser();
            Expression expression = parser.parseExpression(key);
            key = expression.getValue(context, String.class);
        } else {
            // 默認(rèn)使用類名+方法名+IP 地址作為 key
            HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
            String ip = getIpAddress(request);
            key = ip + ":" + className + ":" + methodName;
        }
        
        return"rate_limit:" + key;
    }
    
    private boolean isLimited(String key, int time, int count) {
        // 使用 Redis 的計(jì)數(shù)器實(shí)現(xiàn)限流
        try {
            Long currentCount = redisTemplate.opsForValue().increment(key, 1);
            
            // 如果是第一次訪問，設(shè)置過期時(shí)間
            if (currentCount == 1) {
                redisTemplate.expire(key, time, TimeUnit.SECONDS);
            }
            
            return currentCount > count;
        } catch (Exception e) {
            log.error("限流異常", e);
            returnfalse;
        }
    }
    
    private String getIpAddress(HttpServletRequest request) {
        String ip = request.getHeader("X-Forwarded-For");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_CLIENT_IP");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("HTTP_X_FORWARDED_FOR");
        }
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }
}

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>31.1-jre</version>
</dependency>

@Component
publicclass RateLimiter {
    // 使用 ConcurrentHashMap 存儲(chǔ)不同接口的令牌桶
    privatefinal ConcurrentHashMap<String, com.google.common.util.concurrent.RateLimiter> rateLimiterMap = new ConcurrentHashMap<>();
    
    /**
     * 獲取特定接口的令牌桶，不存在則創(chuàng)建
     * @param key 限流鍵
     * @param permitsPerSecond 每秒允許的請(qǐng)求量
     * @return 令牌桶實(shí)例
     */
    public com.google.common.util.concurrent.RateLimiter getRateLimiter(String key, double permitsPerSecond) {
        return rateLimiterMap.computeIfAbsent(key, 
            k -> com.google.common.util.concurrent.RateLimiter.create(permitsPerSecond));
    }
    
    /**
     * 嘗試獲取令牌
     * @param key 限流鍵
     * @param permitsPerSecond 每秒允許的請(qǐng)求量
     * @param timeout 超時(shí)時(shí)間
     * @param unit 時(shí)間單位
     * @return 是否獲取成功
     */
    public boolean tryAcquire(String key, double permitsPerSecond, long timeout, TimeUnit unit) {
        com.google.common.util.concurrent.RateLimiter rateLimiter = getRateLimiter(key, permitsPerSecond);
        return rateLimiter.tryAcquire(1, timeout, unit);
    }
}

@Configuration
public class WebConfig implements WebMvcConfigurer {
    
    @Autowired
    private TokenBucketInterceptor tokenBucketInterceptor;
    
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(tokenBucketInterceptor)
                .addPathPatterns("/**");
    }
}

@Service
@Slf4j
publicclass RedisRateLimiterService {
    
    @Autowired
    private StringRedisTemplate redisTemplate;
    
    private DefaultRedisScript<Long> rateLimiterScript;
    
    @PostConstruct
    public void init() {
        // 加載 Lua 腳本
        rateLimiterScript = new DefaultRedisScript<>();
        rateLimiterScript.setLocation(new ClassPathResource("scripts/rate_limiter.lua"));
        rateLimiterScript.setResultType(Long.class);
    }
    
    /**
     * 嘗試獲取訪問權(quán)限
     * @param key 限流鍵
     * @param window 時(shí)間窗口（秒）
     * @param threshold 閾值
     * @return 剩余可用請(qǐng)求數(shù)，-1 表示被限流
     */
    public long isAllowed(String key, int window, int threshold) {
        try {
            // 執(zhí)行 lua 腳本
            List<String> keys = Collections.singletonList(key);
            Long remainingCount = redisTemplate.execute(
                rateLimiterScript, 
                keys, 
                String.valueOf(window), 
                String.valueOf(threshold),
                String.valueOf(System.currentTimeMillis())
            );
            
            return remainingCount == null ? -1 : remainingCount;
        } catch (Exception e) {
            log.error("Redis rate limiter error", e);
            // 發(fā)生異常時(shí)放行請(qǐng)求
            return threshold;
        }
    }
}

@Aspect
@Component
@Slf4j
publicclass DistributedRateLimitAspect {
    
    @Autowired
    private RedisRateLimiterService rateLimiterService;
    
    @Autowired(required = false)
    private HttpServletRequest request;
    
    @Around("@annotation(rateLimit)")
    public Object around(ProceedingJoinPoint pjp, DistributedRateLimit rateLimit) throws Throwable {
        String key = generateKey(pjp, rateLimit);
        
        long remainingCount = rateLimiterService.isAllowed(
            key, 
            rateLimit.window(), 
            rateLimit.threshold()
        );
        
        if (remainingCount < 0) {
            thrownew RuntimeException("接口訪問過于頻繁，請(qǐng)稍后再試");
        }
        
        // 執(zhí)行目標(biāo)方法
        return pjp.proceed();
    }
    
    private String generateKey(ProceedingJoinPoint pjp, DistributedRateLimit rateLimit) {
        String methodName = pjp.getSignature().getName();
        String className = pjp.getTarget().getClass().getName();
        StringBuilder key = new StringBuilder(rateLimit.prefix());
        
        key.append(className).append(".").append(methodName);
        
        // 根據(jù)限流模式添加不同的后綴
        switch (rateLimit.mode()) {
            case"ip":
                // 按 IP 限流
                key.append(":").append(getIpAddress());
                break;
            case"user":
                // 按用戶限流
                Object userId = getUserId();
                key.append(":").append(userId != null ? userId : "anonymous");
                break;
            case"all":
                // 接口總體限流，不添加后綴
                break;
            default:
                key.append(":").append(getIpAddress());
                break;
        }
        
        return key.toString();
    }
    
    private String getIpAddress() {
        // IP 獲取方法同上
        if (request == null) {
            return"unknown";
        }
        // 獲取 IP 的代碼同上一個(gè)示例
        return"127.0.0.1"; // 簡(jiǎn)化處理
    }
    
    // 獲取當(dāng)前用戶 ID，根據(jù)實(shí)際認(rèn)證系統(tǒng)實(shí)現(xiàn)
    private Object getUserId() {
        // 這里簡(jiǎn)化處理，實(shí)際中應(yīng)從認(rèn)證信息中獲取
        // 例如：SecurityContextHolder.getContext().getAuthentication().getPrincipal()
        returnnull;
    }
}

@RestController
@RequestMapping("/api")
publicclass PaymentController {
    
    @DistributedRateLimit(prefix = "pay:", window = 3600, threshold = 5, mode = "user")
    @PostMapping("/payment")
    public Result createPayment(@RequestBody PaymentRequest paymentRequest) {
        // 創(chuàng)建支付業(yè)務(wù)邏輯
        return paymentService.createPayment(paymentRequest);
    }
    
    @DistributedRateLimit(window = 60, threshold = 30, mode = "ip")
    @GetMapping("/products")
    public List<Product> getProducts() {
        // 查詢產(chǎn)品列表
        return productService.findAll();
    }
    
    @DistributedRateLimit(window = 1, threshold = 100, mode = "all")
    @GetMapping("/hot/resource")
    public Resource getHotResource() {
        // 獲取熱門資源
        return resourceService.getHotResource();
    }
}

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
    <version>2021.0.4.0</version>
</dependency>

# Sentinel 控制臺(tái)地址
spring.cloud.sentinel.transport.dashboard=localhost:8080
# 取消 Sentinel 控制臺(tái)懶加載
spring.cloud.sentinel.eager=true
# 應(yīng)用名稱
spring.application.name=my-application

@Component
publicclass UrlCleaner implements RequestOriginParser {
    
    @Override
    public String parseOrigin(HttpServletRequest request) {
        // 獲取請(qǐng)求的 URL 路徑
        String path = request.getRequestURI();
        
        // 可以添加更復(fù)雜的解析邏輯，例如：
        // 1. 去除路徑變量：/api/user/123 -> /api/user/{id}
        // 2. 添加請(qǐng)求方法前綴：GET:/api/user
        
        return path;
    }
}

@RestControllerAdvice
publicclass SentinelExceptionHandler {
    
    @ExceptionHandler(BlockException.class)
    public Result handleBlockException(BlockException e) {
        String message = "請(qǐng)求過于頻繁，請(qǐng)稍后再試";
        if (e instanceof FlowException) {
            message = "接口限流：" + message;
        } elseif (e instanceof DegradeException) {
            message = "服務(wù)降級(jí)：系統(tǒng)繁忙，請(qǐng)稍后再試";
        } elseif (e instanceof ParamFlowException) {
            message = "熱點(diǎn)參數(shù)限流：請(qǐng)求過于頻繁";
        } elseif (e instanceof SystemBlockException) {
            message = "系統(tǒng)保護(hù)：系統(tǒng)資源不足";
        } elseif (e instanceof AuthorityException) {
            message = "授權(quán)控制：沒有訪問權(quán)限";
        }
        
        return Result.error(429, message);
    }
}

@RestController
@RequestMapping("/api")
publicclass UserController {
    
    // 使用資源名定義限流資源
    @SentinelResource(value = "getUserById", 
                      blockHandler = "getUserBlockHandler",
                      fallback = "getUserFallback")
    @GetMapping("/user/{id}")
    public User getUser(@PathVariable Long id) {
        return userService.getUser(id);
    }
    
    // 限流處理方法
    public User getUserBlockHandler(Long id, BlockException e) {
        log.warn("Get user request blocked: {}", id, e);
        thrownew RuntimeException("請(qǐng)求頻率過高，請(qǐng)稍后再試");
    }
    
    // 異常回退方法
    public User getUserFallback(Long id, Throwable t) {
        log.error("Get user failed: {}", id, t);
        User fallbackUser = new User();
        fallbackUser.setId(id);
        fallbackUser.setName("Unknown");
        return fallbackUser;
    }
}

@Service
@Slf4j
publicclass SentinelRuleService {
    
    public void initComplexFlowRules() {
        List<FlowRule> rules = new ArrayList<>();
        
        // 基于 QPS + 調(diào)用關(guān)系的限流規(guī)則
        FlowRule apiRule = new FlowRule();
        apiRule.setResource("/api/data");
        apiRule.setGrade(RuleConstant.FLOW_GRADE_QPS);
        apiRule.setCount(20);
        
        // 限制調(diào)用來源
        apiRule.setLimitApp("frontend"); // 只限制來自前端應(yīng)用的調(diào)用
        
        // 流控策略：關(guān)聯(lián)資源
        apiRule.setStrategy(RuleConstant.STRATEGY_RELATE);
        apiRule.setRefResource("/api/important"); // 當(dāng) important 接口 QPS 高時(shí)，限制 data 接口
        
        rules.add(apiRule);
        
        // 基于并發(fā)線程數(shù)的限流
        FlowRule threadRule = new FlowRule();
        threadRule.setResource("/api/heavy-task");
        threadRule.setGrade(RuleConstant.FLOW_GRADE_THREAD); // 基于線程數(shù)
        threadRule.setCount(5); // 最多 5 個(gè)線程同時(shí)處理
        rules.add(threadRule);
        
        // 加載規(guī)則
        FlowRuleManager.loadRules(rules);
    }
    
    public void initHotspotRules() {
        // 熱點(diǎn)參數(shù)限流規(guī)則
        List<ParamFlowRule> rules = new ArrayList<>();
        
        ParamFlowRule rule = new ParamFlowRule("/api/product");
        // 對(duì)第 0 個(gè)參數(shù)（productId）進(jìn)行限流
        rule.setParamIdx(0);
        rule.setCount(5);
        
        // 特例配置
        ParamFlowItem item1 = new ParamFlowItem();
        item1.setObject("1"); // productId = 1 的商品
        item1.setCount(10);  // 可以有更高的 QPS
        
        ParamFlowItem item2 = new ParamFlowItem();
        item2.setObject("2"); // productId = 2 的商品
        item2.setCount(2);   // 更嚴(yán)格的限制
        
        rule.setParamFlowItemList(Arrays.asList(item1, item2));
        
        rules.add(rule);
        ParamFlowRuleManager.loadRules(rules);
    }
}

<dependency>
    <groupId>com.github.whvcse</groupId>
    <artifactId>easy-captcha</artifactId>
    <version>1.6.2</version>
</dependency>

@Service
publicclass CaptchaService {
    
    @Autowired
    private StringRedisTemplate redisTemplate;
    
    privatestaticfinallong CAPTCHA_EXPIRE_TIME = 5 * 60; // 5 分鐘
    
    /**
     * 生成驗(yàn)證碼
     * @param request HTTP 請(qǐng)求
     * @param response HTTP 響應(yīng)
     * @return 驗(yàn)證碼 Base64 字符串
     */
    public String generateCaptcha(HttpServletRequest request, HttpServletResponse response) {
        // 生成驗(yàn)證碼
        SpecCaptcha captcha = new SpecCaptcha(130, 48, 5);
        
        // 生成驗(yàn)證碼 ID
        String captchaId = UUID.randomUUID().toString();
        
        // 將驗(yàn)證碼存入 Redis
        redisTemplate.opsForValue().set(
            "captcha:" + captchaId, 
            captcha.text().toLowerCase(), 
            CAPTCHA_EXPIRE_TIME, 
            TimeUnit.SECONDS
        );
        
        // 設(shè)置 Cookie
        Cookie cookie = new Cookie("captchaId", captchaId);
        cookie.setMaxAge((int) CAPTCHA_EXPIRE_TIME);
        cookie.setPath("/");
        response.addCookie(cookie);
        
        // 返回 Base64 編碼的驗(yàn)證碼圖片
        return captcha.toBase64();
    }
    
    /**
     * 驗(yàn)證驗(yàn)證碼
     * @param request HTTP 請(qǐng)求
     * @param captchaCode 用戶輸入的驗(yàn)證碼
     * @return 是否驗(yàn)證通過
     */
    public boolean validateCaptcha(HttpServletRequest request, String captchaCode) {
        // 從 Cookie 獲取驗(yàn)證碼 ID
        Cookie[] cookies = request.getCookies();
        String captchaId = null;
        
        if (cookies != null) {
            for (Cookie cookie : cookies) {
                if ("captchaId".equals(cookie.getName())) {
                    captchaId = cookie.getValue();
                    break;
                }
            }
        }
        
        if (captchaId == null) {
            returnfalse;
        }
        
        // 從 Redis 獲取正確的驗(yàn)證碼
        String key = "captcha:" + captchaId;
        String correctCode = redisTemplate.opsForValue().get(key);
        
        // 驗(yàn)證成功后刪除驗(yàn)證碼
        if (correctCode != null && correctCode.equals(captchaCode.toLowerCase())) {
            redisTemplate.delete(key);
            returntrue;
        }
        
        returnfalse;
    }
}

@RestController
@RequestMapping("/api/captcha")
public class CaptchaController {
    
    @Autowired
    private CaptchaService captchaService;
    
    @GetMapping
    public Map<String, String> getCaptcha(HttpServletRequest request, HttpServletResponse response) {
        String base64 = captchaService.generateCaptcha(request, response);
        return Map.of("captcha", base64);
    }
}

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface CaptchaRequired {
    String captchaParam() default "captchaCode";
}

@Component
publicclass CaptchaInterceptor implements HandlerInterceptor {
    
    @Autowired
    private CaptchaService captchaService;
    
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        if (!(handler instanceof HandlerMethod)) {
            returntrue;
        }
        
        HandlerMethod handlerMethod = (HandlerMethod) handler;
        CaptchaRequired captchaRequired = handlerMethod.getMethodAnnotation(CaptchaRequired.class);
        
        if (captchaRequired == null) {
            returntrue;
        }
        
        // 獲取驗(yàn)證碼參數(shù)
        String captchaParam = captchaRequired.captchaParam();
        String captchaCode = request.getParameter(captchaParam);
        
        if (StringUtils.hasText(captchaCode)) {
            // 驗(yàn)證驗(yàn)證碼
            boolean valid = captchaService.validateCaptcha(request, captchaCode);
            if (valid) {
                returntrue;
            }
        }
        
        // 驗(yàn)證失敗
        response.setContentType("application/json;charset=UTF-8");
        response.setStatus(HttpStatus.BAD_REQUEST.value());
        response.getWriter().write("{\"code\":400,\"message\":\"驗(yàn)證碼錯(cuò)誤或已過期\"}");
        returnfalse;
    }
}

@Service
@Slf4j
publicclass BehaviorAnalysisService {
    
    @Autowired
    private StringRedisTemplate redisTemplate;
    
    /**
     * 檢查是否是可疑的機(jī)器行為
     * @param request HTTP 請(qǐng)求
     * @return 是否可疑
     */
    public boolean isSuspicious(HttpServletRequest request) {
        // 1. 獲取客戶端信息
        String ip = getIpAddress(request);
        String userAgent = request.getHeader("User-Agent");
        String requestId = request.getSession().getId();
        
        // 2. 檢查訪問頻率
        String freqKey = "behavior:freq:" + ip;
        Long count = redisTemplate.opsForValue().increment(freqKey, 1);
        redisTemplate.expire(freqKey, 1, TimeUnit.MINUTES);
        
        if (count != null && count > 30) {
            log.warn("訪問頻率異常: IP={}, count={}", ip, count);
            returntrue;
        }
        
        // 3. 檢查 User-Agent
        if (userAgent == null || isBotuserAgent(userAgent)) {
            log.warn("可疑的 User-Agent: {}", userAgent);
            returntrue;
        }
        
        // 4. 檢查請(qǐng)求時(shí)間模式
        String timeKey = "behavior:time:" + ip;
        long now = System.currentTimeMillis();
        String lastTimeStr = redisTemplate.opsForValue().get(timeKey);
        
        if (lastTimeStr != null) {
            long lastTime = Long.parseLong(lastTimeStr);
            long interval = now - lastTime;
            
            // 如果請(qǐng)求間隔非常均勻，可能是機(jī)器人
            if (isUniformInterval(ip, interval)) {
                log.warn("請(qǐng)求間隔異常均勻: IP={}, interval={}", ip, interval);
                returntrue;
            }
        }
        
        redisTemplate.opsForValue().set(timeKey, String.valueOf(now), 10, TimeUnit.MINUTES);
        
        // 更多高級(jí)檢測(cè)邏輯...
        
        returnfalse;
    }
    
    /**
     * 檢查是否是機(jī)器人 UA
     */
    private boolean isBotuserAgent(String userAgent) {
        String ua = userAgent.toLowerCase();
        return ua.contains("bot") || ua.contains("spider") || ua.contains("crawl") ||
               ua.isEmpty() || ua.length() < 40;
    }
    
    /**
     * 檢查請(qǐng)求間隔是否異常均勻
     */
    private boolean isUniformInterval(String ip, long interval) {
        String key = "behavior:intervals:" + ip;
        
        // 獲取最近的幾個(gè)間隔
        List<String> intervalStrs = redisTemplate.opsForList().range(key, 0, 4);
        redisTemplate.opsForList().leftPush(key, String.valueOf(interval));
        redisTemplate.opsForList().trim(key, 0, 9);  // 只保留最近 10 個(gè)
        redisTemplate.expire(key, 10, TimeUnit.MINUTES);
        
        if (intervalStrs == null || intervalStrs.size() < 5) {
            returnfalse;
        }
        
        // 計(jì)算間隔的方差，方差小說明請(qǐng)求間隔很均勻
        List<Long> intervals = intervalStrs.stream()
                .map(Long::parseLong)
                .collect(Collectors.toList());
        
        double mean = intervals.stream().mapToLong(Long::longValue).average().orElse(0);
        double variance = intervals.stream()
                .mapToDouble(i -> Math.pow(i - mean, 2))
                .average()
                .orElse(0);
        
        return variance < 100;  // 方差閾值，需要根據(jù)實(shí)際情況調(diào)整
    }
    
    // getIpAddress 方法同上
}

@Component
publicclass BehaviorAnalysisInterceptor implements HandlerInterceptor {
    
    @Autowired
    private BehaviorAnalysisService behaviorAnalysisService;
    
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 對(duì)于需要保護(hù)的端點(diǎn)進(jìn)行檢查
        String path = request.getRequestURI();
        if (path.startsWith("/api/") && isPotentialRiskEndpoint(path)) {
            boolean suspicious = behaviorAnalysisService.isSuspicious(request);
            
            if (suspicious) {
                // 需要驗(yàn)證碼或其他額外驗(yàn)證
                response.setContentType("application/json;charset=UTF-8");
                response.setStatus(HttpStatus.TOO_MANY_REQUESTS.value());
                response.getWriter().write("{\"code\":429,\"message\":\"檢測(cè)到異常訪問，請(qǐng)進(jìn)行驗(yàn)證\",\"needCaptcha\":true}");
                returnfalse;
            }
        }
        
        returntrue;
    }
    
    /**
     * 判斷是否是高風(fēng)險(xiǎn)端點(diǎn)
     */
    private boolean isPotentialRiskEndpoint(String path) {
        return path.contains("/login") || 
               path.contains("/register") || 
               path.contains("/payment") || 
               path.contains("/order") ||
               path.contains("/password");
    }
}

@RestController
@RequestMapping("/api")
publicclass UserController {
    
    @CaptchaRequired
    @PostMapping("/login")
    public Result login(@RequestParam String username, 
                        @RequestParam String password,
                        @RequestParam String captchaCode) {
        // 登錄邏輯
        return userService.login(username, password);
    }
    
    @CaptchaRequired
    @PostMapping("/register")
    public Result register(@RequestBody UserRegisterDTO registerDTO,
                          @RequestParam String captchaCode) {
        // 注冊(cè)邏輯
        return userService.register(registerDTO);
    }
}