Il est également conçu pour fonctionner comme une référence future.

Vous pouvez donc revenir et voir exactement ce dont vous avez besoin.

## Exécuter le code

Tous les blocs de code peuvent être copiés et utilisés directement (il s'agit en fait de fichiers Python testés).

Pour exécuter l'un de ces exemples, copiez le code dans un fichier `main.py`, et commencez `uvicorn` avec :

<div class="termy">

```console

  }

  private fun newVirtualThreadPerTaskExecutor(): ExecutorService {
    return Executors::class.java.getMethod("newVirtualThreadPerTaskExecutor").invoke(null) as ExecutorService
  }

  @Test
  fun testRequest() {
    server.enqueue(MockResponse())

    val request = Request(server.url("/"))

    client.newCall(request).execute().use {
      assertThat(it.code).isEqualTo(200)
    }
  }

  @Test

```

Quando você cria um gerenciador de contexto ou um gerenciador de contexto assíncrono como mencionado acima, o que ele faz é que, antes de entrar no bloco `with`, ele irá executar o código anterior ao `yield`, e depois de sair do bloco `with`, ele irá executar o código depois do `yield`.

No nosso exemplo de código acima, nós não usamos ele diretamente, mas nós passamos para o FastAPI para ele usá-lo.

import com.google.common.testing.TestLogHandler;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.logging.Level;
import java.util.logging.Logger;
import junit.framework.TestCase;

/** Tests for {@link ListenerCallQueue}. */
public class ListenerCallQueueTest extends TestCase {

import com.google.common.testing.TestLogHandler;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.logging.Level;
import java.util.logging.Logger;
import junit.framework.TestCase;

/** Tests for {@link ListenerCallQueue}. */
public class ListenerCallQueueTest extends TestCase {

import java.util.concurrent.CancellationException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Used to test listenable future implementations.
 *
 * @author Sven Mawson
 */
public class ListenableFutureTester {

   *
   * @throws IOException if the request could not be executed due to cancellation, a connectivity
   *     problem or timeout. Because networks can fail during an exchange, it is possible that the
   *     remote server accepted the request before the failure.
   * @throws IllegalStateException when the call has already been executed.
   */
  @Throws(IOException::class)
  fun execute(): Response

  /**

import com.google.common.annotations.J2ktIncompatible;
import java.util.ArrayList;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import junit.framework.TestCase;

/**
 * Basher test for {@link AtomicLongMap}.
 *
 * @author mike nonemacher
 */
@J2ktIncompatible // threads

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import junit.framework.TestCase;

/**
 * Test case for {@link ListenableFutureTask}.
 *
 * @author Sven Mawson
 */
public class ListenableFutureTaskTest extends TestCase {