生产配置

Executors的陷阱 阿里巴巴Java开发手册明确规定：禁止使用Executors创建线程池。 三大陷阱 1. FixedThreadPool和SingleThreadExecutor // 源码 public static ExecutorService newFixedThreadPool(int nThreads) { return new ThreadPoolExecutor(nThreads, nThreads, 0L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>()); // 无界队列 } 问题：队列无界，任务堆积导致OOM 2. CachedThreadPool public static ExecutorService newCachedThreadPool() { return new ThreadPoolExecutor(0, Integer.MAX_VALUE, // 无限线程 60L, TimeUnit.SECONDS, new SynchronousQueue<Runnable>()); } 问题：线程数无限，可能创建大量线程导致OOM 3. ScheduledThreadPool public static ScheduledExecutorService newScheduledThreadPool(int corePoolSize) { return new ScheduledThreadPoolExecutor(corePoolSize); // 内部使用DelayedWorkQueue，无界 } 问题：队列无界，任务堆积 生产级配置模板 模板1：Web服务 @Configuration public class ThreadPoolConfig { @Bean("webExecutor") public ThreadPoolExecutor webExecutor() { int coreSize = Runtime.getRuntime().availableProcessors() * 2; return new ThreadPoolExecutor( coreSize, // 核心线程数 coreSize * 4, // 最大线程数 60L, TimeUnit.SECONDS, // 空闲存活时间 new ArrayBlockingQueue<>(1000), // 有界队列 new NamedThreadFactory("web-pool"), new ThreadPoolExecutor.CallerRunsPolicy() // 降级策略 ); } } // 自定义线程工厂 class NamedThreadFactory implements ThreadFactory { private final AtomicInteger threadNumber = new AtomicInteger(1); private final String namePrefix; public NamedThreadFactory(String namePrefix) { this.namePrefix = namePrefix; } @Override public Thread newThread(Runnable r) { Thread t = new Thread(r, namePrefix + "-" + threadNumber.getAndIncrement()); t.setDaemon(false); return t; } } 模板2：异步任务 @Bean("asyncExecutor") public ThreadPoolExecutor asyncExecutor() { return new ThreadPoolExecutor( 10, // 核心线程数 20, // 最大线程数 300L, TimeUnit.SECONDS, // 较长的空闲时间 new LinkedBlockingQueue<>(500), // 较大队列 new NamedThreadFactory("async-pool"), (r, executor) -> { // 自定义拒绝策略：记录日志 log.error("Task rejected: {}", r); // 可以保存到数据库或MQ } ); } 异常处理 问题：线程池中的异常不会抛出 ...