【技术解读】Flutter 3.44 发布前夕，官方宣布 SwiftPM 将完全取代 Coc深度剖析

┌─────────────────────────────────────┐
│           应用层 (Application)        │
├─────────────────────────────────────┤
│           核心层 (Core)              │
├─────────────────────────────────────┤
│           基础层 (Infrastructure)     │
└─────────────────────────────────────┘

// 核心处理器
public class CoreProcessor {
    
    private final ExecutorService executor;
    private final CacheManager cacheManager;
    
    public CoreProcessor() {
        this.executor = Executors.newFixedThreadPool(
            Runtime.getRuntime().availableProcessors() * 2
        );
        this.cacheManager = new CacheManager();
    }
    
    /**
     * 处理请求
     * @param request 请求对象
     * @return 处理结果
     */
    public Result process(Request request) {
        // 1. 参数校验
        validateRequest(request);
        
        // 2. 查询缓存
        String cacheKey = generateCacheKey(request);
        Result cachedResult = cacheManager.get(cacheKey);
        if (cachedResult != null) {
            return cachedResult;
        }
        
        // 3. 异步处理
        CompletableFuture future = CompletableFuture.supplyAsync(() -> {
            return doProcess(request);
        }, executor);
        
        // 4. 获取结果并缓存
        Result result = future.join();
        cacheManager.put(cacheKey, result, Duration.ofMinutes(30));
        
        return result;
    }
    
    private Result doProcess(Request request) {
        // 实际业务逻辑
        return new Result("success");
    }
    
    private void validateRequest(Request request) {
        if (request == null) {
            throw new IllegalArgumentException("请求不能为空");
        }
    }
    
    private String generateCacheKey(Request request) {
        return String.format("%s:%s:%s", 
            request.getType(), 
            request.getId(),
            request.getTimestamp()
        );
    }
}

# application.yml 配置示例
tech:
  core:
    thread-pool:
      core-size: 8
      max-size: 16
      queue-capacity: 100
      keep-alive: 60s
    cache:
      enabled: true
      ttl: 30m
      max-size: 1000
    retry:
      max-attempts: 3
      backoff: 1s

// ❌ 错误配置
ExecutorService executor = Executors.newCachedThreadPool();
// 问题：线程数量无上限，可能导致 OOM

// ✅ 正确配置
ExecutorService executor = new ThreadPoolExecutor(
    8,                              // 核心线程数
    16,                             // 最大线程数
    60L, TimeUnit.SECONDS,          // 空闲线程存活时间
    new LinkedBlockingQueue<>(100), // 任务队列
    new ThreadPoolExecutor.CallerRunsPolicy() // 拒绝策略
);

// ❌ 错误示例
public Result getFromCache(String key) {
    Result result = cache.get(key);
    if (result == null) {
        // 缓存未命中，直接查询数据库
        result = db.query(key);
        cache.put(key, result);
    }
    return result;
}

// ✅ 正确示例（布隆过滤器 + 空值缓存）
public Result getFromCache(String key) {
    // 1. 布隆过滤器快速判断
    if (!bloomFilter.mightContain(key)) {
        return null;
    }
    
    // 2. 查询缓存
    Result result = cache.get(key);
    if (result != null) {
        return result.equals(NULL_PLACEHOLDER) ? null : result;
    }
    
    // 3. 查询数据库
    result = db.query(key);
    cache.put(key, result != null ? result : NULL_PLACEHOLDER);
    
    return result;
}