initialized = true;
    }

    /**
     * Returns the logger adapter factory.
     * <p>
     * Detects available logging frameworks in the following order:
     * 1. SLF4J (if available)
     * 2. Commons Logging (if available)
     * 3. java.util.logging (fallback)
     * </p>
     *
     * @return the logger adapter factory
     */
    protected static LoggerAdapterFactory getLoggerAdapterFactory() {

            # Pydantic >= 2.12.0 warns about field specific metadata that is unused
            # (e.g. `TypeAdapter(Annotated[int, Field(alias='b')])`). In some cases, we
            # end up building the type adapter from a model field annotation so we
            # need to ignore the warning:
            if shared.PYDANTIC_VERSION_MINOR_TUPLE >= (2, 12):
                from pydantic.warnings import UnsupportedFieldAttributeWarning

Les modèles, bien qu'ils soient généralement livrés avec une configuration spécifique, sont conçus pour être flexibles et personnalisables. Cela vous permet de les modifier et de les adapter aux exigences de votre projet, ce qui en fait un excellent point de départ. 🏁

 * code changes, you can use <a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/guava/latest/com.github.benmanes.caffeine.guava/com/github/benmanes/caffeine/guava/CaffeinatedGuava.html">its
 * {@code CaffeinatedGuava} adapter class</a>, which lets you build a Guava {@code Cache} or a Guava
 * {@code LoadingCache} backed by a Guava {@code CacheLoader}.
 *
 * <p>Caffeine's API for asynchronous operations uses {@code CompletableFuture}: <a

Vous pouvez utiliser [`bump-pydantic`](https://github.com/pydantic/bump-pydantic) de la même équipe Pydantic.

Cet outil vous aidera à modifier automatiquement la majeure partie du code à adapter.

Après cela, vous pouvez exécuter les tests et vérifier que tout fonctionne. Si c'est le cas, vous avez terminé. 😎

## Pydantic v1 dans v2 { #pydantic-v1-in-v2 }

 * code changes, you can use <a
 * href="https://www.javadoc.io/doc/com.github.ben-manes.caffeine/guava/latest/com.github.benmanes.caffeine.guava/com/github/benmanes/caffeine/guava/CaffeinatedGuava.html">its
 * {@code CaffeinatedGuava} adapter class</a>, which lets you build a Guava {@code Cache} or a Guava
 * {@code LoadingCache} backed by a Guava {@code CacheLoader}.
 *
 * <p>Caffeine's API for asynchronous operations uses {@code CompletableFuture}: <a

=== ":material-language-kotlin: Kotlin"
    ```kotlin
      private val client = OkHttpClient()
      private val moshi = Moshi.Builder().build()
      private val gistJsonAdapter = moshi.adapter(Gist::class.java)

      fun run() {
        val request = Request.Builder()
            .url("https://api.github.com/gists/c2a7c39532239ff261be")
            .build()

/// tip

If you want to **learn FastAPI** in a structured way (recommended), go and read the [Tutorial - User Guide](../tutorial/index.md) chapter by chapter instead.

As you saw in the previous chapter about [Deployment Concepts](concepts.md), there are multiple strategies you can use.

Here I'll show you how to use **Uvicorn** with **worker processes** using the `fastapi` command or the `uvicorn` command directly.

/// info

If you are using containers, for example with Docker or Kubernetes, I'll tell you more about that in the next chapter: [FastAPI in Containers - Docker](docker.md).

# Simple OAuth2 with Password and Bearer { #simple-oauth2-with-password-and-bearer }

Now let's build from the previous chapter and add the missing parts to have a complete security flow.

## Get the `username` and `password` { #get-the-username-and-password }

We are going to use **FastAPI** security utilities to get the `username` and `password`.