如何使用Junit测试异步进程

import org.junit.Rule;
import org.junit.Test;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import static org.junit.Assert.assertEquals;

public class AsyncTest {

    @Test
    public void testAsyncProcess() throws InterruptedException {
        // 创建一个异步任务
        CompletableFuture<String> future = new CompletableFuture<>();

        // 创建一个计数器，让测试等待异步任务完成
        CountDownLatch latch = new CountDownLatch(1);

        // 创建一个线程池，用于执行异步任务
        ExecutorService executor = Executors.newSingleThreadExecutor();

        // 在异步任务完成时，执行一些操作
        future.thenAccept(result -> {
            assertEquals("expected result", result);
            latch.countDown();
        });

        // 提交异步任务
        executor.submit(() -> {
            // 模拟异步任务的执行时间
            try {
                TimeUnit.SECONDS.sleep(2);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            future.complete("expected result");
        });

        // 等待异步任务完成
        latch.await();

        // 关闭线程池
        executor.shutdown();
    }
}