多线程测试代码

ThreadTest.java

import org.junit.Test;

import java.util.concurrent.*;
import java.util.function.Supplier;

public class ThreadTest {

    private static final ScheduledExecutorService schedulerExecutor =
            Executors.newScheduledThreadPool(10);
    private static final ExecutorService executorService =
            Executors.newCachedThreadPool();


    public static <T> CompletableFuture<T> supplyAsync(
            final Supplier<T> supplier, long timeoutValue, TimeUnit timeUnit,
            T defaultValue) {

        final CompletableFuture<T> cf = new CompletableFuture<T>();

        // as pointed out by Peti, the ForkJoinPool.commonPool() delivers a
        // ForkJoinTask implementation of Future, that doesn't interrupt when cancelling
        // Using Executors.newCachedThreadPool instead in the example
        // submit task
        Future<?> future = executorService.submit(() -> {
            try {
                cf.complete(supplier.get());
            } catch (Throwable ex) {
                cf.completeExceptionally(ex);
            }
        });

        //schedule watcher
        schedulerExecutor.schedule(() -> {
            if (!cf.isDone()) {
                cf.complete(defaultValue);
                future.cancel(true);
            }

        }, timeoutValue, timeUnit);

        return cf;
    }

    /**
     * 异步超时
     * @throws Exception
     */
    @Test
    public void syncTimeoutTest() throws Exception {
        CompletableFuture<String> a = supplyAsync(() -> {
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e1) {
                e1.printStackTrace();
            }
            return "hi";
        }, 1, TimeUnit.SECONDS, "default");

        System.out.println(a.get());
    }

}