* extends the basic {@link Source} interface with specific functionality for handling
 * Maven POM files and resolving related project POMs.
 *
 * <p>The interface provides two types of sources:</p>
 * <ul>
 *   <li>Build sources: Used for POM files of projects being built by Maven in the filesystem.
 *       These sources support resolving related POMs using the {@link ModelLocator}.</li>

     *
     * @param message The message describing the problem, may be {@code null}.
     * @param severity The severity level of the problem, may be {@code null} to default to
     *            {@link ModelProblem.Severity#ERROR}.
     * @param source The source of the problem, may be {@code null}.
     * @param lineNumber The one-based index of the line containing the error or {@code -1} if unknown.

/**
 * Signals one ore more errors during model building. The model builder tries to collect as many problems as possible
 * before eventually failing to provide callers with rich error information. Use {@link #getProblems()} to query the
 * details of the failure.
 *
 * @deprecated use {@code org.apache.maven.api.services.ModelBuilder} instead
 */
@Deprecated(since = "4.0.0")

## 結論

透過這個教學，你應該對**環境變數**是什麼以及如何在 Python 中使用它們有了基本的了解。

你也可以在<a href="https://zh.wikipedia.org/wiki/%E7%8E%AF%E5%A2%83%E5%8F%98%E9%87%8F" class="external-link" target="_blank">環境變數 - 維基百科</a> (<a href="https://en.wikipedia.org/wiki/Environment_variable" class="external-link" target="_blank">Wikipedia for Environment Variable</a>) 中了解更多關於它們的資訊。

在許多情況下，環境變數的用途和適用性可能不會立刻顯現。但是在開發過程中，它們會在許多不同的場景中出現，因此瞭解它們是非常必要的。

/// tip | Dica

Se você deseja **aprender FastAPI** de forma estruturada (recomendado), leia capítulo por capítulo [Tutorial - Guia de Usuário](../tutorial/index.md){.internal-link target=_blank} em vez disso.

/// info

You can read more about the Starlette `lifespan` handlers in <a href="https://www.starlette.dev/lifespan/" class="external-link" target="_blank">Starlette's  Lifespan' docs</a>.

/// info | Informação

Você pode ler mais sobre os manipuladores de `lifespan` do Starlette na <a href="https://www.starlette.dev/lifespan/" class="external-link" target="_blank">Documentação do Lifespan do Starlette</a>.

import org.codehaus.plexus.component.configurator.expression.TypeAwareExpressionEvaluator;
import org.codehaus.plexus.configuration.PlexusConfiguration;

/**
 * An enhanced {@link ObjectWithFieldsConverter} leveraging the {@link TypeAwareExpressionEvaluator}
 * interface.
 */
class EnhancedConfigurationConverter extends ObjectWithFieldsConverter {

    // Cache for expression evaluation results to avoid repeated evaluations

하지만 `Request` 객체에 직접 접근해야 하는 상황이 있을 수 있습니다.

## `Request` 객체에 대한 세부 사항

**FastAPI**는 실제로 내부에 **Starlette**을 사용하며, 그 위에 여러 도구를 덧붙인 구조입니다. 따라서 여러분이 필요할 때 Starlette의 <a href="https://www.starlette.dev/requests/" class="external-link" target="_blank">`Request`</a> 객체를 직접 사용할 수 있습니다.

`Request` 객체에서 데이터를 직접 가져오는 경우(예: 본문을 읽기)에는 FastAPI가 해당 데이터를 검증하거나 변환하지 않으며, 문서화(OpenAPI를 통한 문서 자동화(로 생성된) API 사용자 인터페이스)도 되지 않습니다.

import java.io.Serializable;
import java.nio.ByteBuffer;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

/**
 * {@link HashFunction} adapter for {@link MessageDigest} instances.
 *
 * @author Kevin Bourrillion
 * @author Dimitris Andreou
 */
@Immutable
final class MessageDigestHashFunction extends AbstractHashFunction implements Serializable {