Java新建一个子线程异步运行方法
如何在运行主方法的同时异步运行另一个方法,我是用来更新缓存;
1. 工具类
public class ThreadPoolUtils { private static final Logger LOGGER = LoggerFactory.getLogger(ThreadPoolUtils.class); private static final String POOL_NAME = "thread-im-runner"; // 等待队列长度 private static final int BLOCKING_QUEUE_LENGTH = 20000; // 闲置线程存活时间 private static final int KEEP_ALIVE_TIME = 5 * 1000; private static ThreadPoolExecutor threadPool = null; private ThreadPoolUtils() { throw new IllegalStateException("utility class"); } /** * 无返回值直接执行 * * @param runnable 需要运行的任务 */ public static void execute(Runnable runnable) { getThreadPool().execute(runnable); } /** * 有返回值执行 主线程中使用Future.get()获取返回值时,会阻塞主线程,直到任务执行完毕 * * @param callable 需要运行的任务 */ public static <T> Future<T> submit(Callable<T> callable) { return getThreadPool().submit(callable); } private static synchronized ThreadPoolExecutor getThreadPool() { if (threadPool == null) { // 核心线程数、最大线程数、闲置线程存活时间、时间单位、线程队列、线程工厂、当前线程数已经超过最大线程数时的异常处理策略 threadPool = new ThreadPoolExecutor(50, 500, KEEP_ALIVE_TIME, TimeUnit.MILLISECONDS, new ArrayBlockingQueue<>(BLOCKING_QUEUE_LENGTH), new ThreadFactoryBuilder().setNameFormat(POOL_NAME + "-%d").build(), new ThreadPoolExecutor.AbortPolicy() { @Override public void rejectedExecution(Runnable r, ThreadPoolExecutor e) { LOGGER.warn("线程过多,当前运行线程总数:{},活动线程数:{}。等待队列已满,等待运行任务数:{}", e.getPoolSize(), e.getActiveCount(), e.getQueue().size()); } }); } return threadPool; } private static synchronized ThreadPoolExecutor getThreadPoolByCpuNum() { if (threadPool == null) { // 获取处理器数量 int cpuNum = Runtime.getRuntime().availableProcessors(); // 根据cpu数量,计算出合理的线程并发数 int maximumPoolSize = cpuNum * 2 + 1; // 核心线程数、最大线程数、闲置线程存活时间、时间单位、线程队列、线程工厂、当前线程数已经超过最大线程数时的异常处理策略 threadPool = new ThreadPoolExecutor(maximumPoolSize - 1, maximumPoolSize, KEEP_ALIVE_TIME, TimeUnit.MILLISECONDS, new ArrayBlockingQueue<>(BLOCKING_QUEUE_LENGTH), new ThreadFactoryBuilder().setNameFormat(POOL_NAME + "-%d").build(), new ThreadPoolExecutor.AbortPolicy() { @Override public void rejectedExecution(Runnable r, ThreadPoolExecutor e) { LOGGER.warn("线程爆炸了,当前运行线程总数:{},活动线程数:{}。等待队列已满,等待运行任务数:{}", e.getPoolSize(), e.getActiveCount(), e.getQueue().size()); } }); } return threadPool; } }
2.实际使用
ThreadPoolUtils.execute(() -> { this.Method(); });