虚拟线程

import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * Virtual thread utils (JDK 21+).
 * 
 * @author Tong Li
 */
public class TioVirtualThreadUtils {

  private static volatile ExecutorService virtualThreadExecutor;

  static {
    start();
  }

  private static ThreadFactory namedVirtualThreadFactory(String baseName) {
    AtomicInteger threadNumber = new AtomicInteger(1);
    return r -> Thread.ofVirtual().name(baseName + "-" + threadNumber.getAndIncrement()).unstarted(r);
  }

  public static ExecutorService getExecutor() {
    return virtualThreadExecutor;
  }

  public static <T> Future<T> submit(Callable<T> task) {
    return virtualThreadExecutor.submit(task);
  }

  public static <T> Future<T> submit(Runnable task, T result) {
    return virtualThreadExecutor.submit(task, result);
  }

  public static Future<?> submit(Runnable task) {
    return virtualThreadExecutor.submit(task);
  }

  public static void execute(Runnable runnable) {
    virtualThreadExecutor.execute(runnable);
  }

  /**
   * Start executor if not started. Uses a per-task virtual thread executor,
   * suitable for IO-bound workloads.
   */
  public static void start() {
    if (virtualThreadExecutor == null) {
      // Two equivalent options:
      // 1) with custom name factory:
      virtualThreadExecutor = Executors.newThreadPerTaskExecutor(namedVirtualThreadFactory("tio-vt"));

      // 2) simplest:
      // virtualThreadExecutor = Executors.newVirtualThreadPerTaskExecutor();
    }
  }

  public static void restart() {
    stop();
    start();
  }

  /**
   * Stop executor immediately. Note: shutdownNow() will attempt to interrupt
   * running tasks.
   */
  public static void stop() {
    if (virtualThreadExecutor != null) {
      virtualThreadExecutor.shutdownNow();
      virtualThreadExecutor = null;
    }
  }
}