Rate Limiter Plugin

对应模块: io.gitee.lcgyl:lcgyl-rate-limiter-plugin

高并发限流组件，保护核心服务免受流量洪峰冲击。

✨ 特性

• ✅ 多维度限流 - 支持按 IP, 用户, API, 全局等多维度组合
• ✅ 经典算法 - 内置令牌桶, 漏桶, 滑动窗口, 固定窗口算法
• ✅ 分布式限流 - 基于 Redis Lua 脚本实现精准的分布式控制
• ✅ 注解驱动 - @RateLimit 轻松接入
• ✅ 结构化日志 - StructuredRateLimiterLogger 统计输出 v2.2.0

🚀 快速开始

依赖引入

implementation 'io.gitee.lcgyl:lcgyl-rate-limiter-plugin:2.2.0'

配置

lcgyl:
  rate-limiter:
    enabled: true
    type: redis  # local, redis
    redis:
      key-prefix: "ratelimit:"
    default:
      limit: 100
      window: 1m
      algorithm: sliding_window  # token_bucket, leaky_bucket, sliding_window, fixed_window

声明式限流（推荐）

@RestController
@RequestMapping("/api")
public class ApiController {
    
    // 简单限流：每分钟最多 100 次请求
    @RateLimit(limit = 100, window = "1m")
    @GetMapping("/products")
    public List<Product> listProducts() {
        return productService.findAll();
    }
    
    // 按用户限流：每个用户每秒最多 10 次
    @RateLimit(limit = 10, window = "1s", keyResolver = "#userId")
    @PostMapping("/orders")
    public Order createOrder(@RequestParam String userId, @RequestBody OrderRequest request) {
        return orderService.create(userId, request);
    }
    
    // 按 IP 限流 + 自定义降级
    @RateLimit(limit = 5, window = "1s", keyResolver = "#request.remoteAddr", fallback = "fallbackMethod")
    @GetMapping("/sensitive")
    public Data getSensitiveData(HttpServletRequest request) {
        return dataService.getSensitive();
    }
    
    public Data fallbackMethod(HttpServletRequest request) {
        return Data.cached();  // 返回缓存数据作为降级
    }
}

编程式限流

@Service
public class SmsService {
    
    @Inject
    private RateLimiter rateLimiter;
    
    public void sendSms(String phone, String content) {
        String key = "sms:" + phone;
        
        // 检查是否允许请求
        if (!rateLimiter.tryAcquire(key, 5, Duration.ofMinutes(1))) {
            throw new RateLimitExceededException("短信发送频率过高，请稍后再试");
        }
        
        // 发送短信
        smsGateway.send(phone, content);
    }
}

v2.2.0 新功能：限流统计日志

@Service
public class RateLimitMonitor {
    
    @Inject
    private StructuredRateLimiterLogger rateLimitLogger;
    
    // 记录限流事件
    public void logRateLimitEvent(String key, boolean allowed) {
        rateLimitLogger.info("rate.limit.check")
            .field("key", key)
            .field("allowed", allowed)
            .field("timestamp", System.currentTimeMillis())
            .log();
    }
    
    // 定期输出统计
    @Scheduled(fixedRate = 60000)
    public void logStatistics() {
        rateLimitLogger.info("rate.limit.stats")
            .field("totalRequests", metrics.getTotalRequests())
            .field("blockedRequests", metrics.getBlockedRequests())
            .field("blockRate", metrics.getBlockRate())
            .log();
    }
}