You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

## Import `Header` { #import-header }

First import `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Declare `Header` parameters { #declare-header-parameters }

Then declare the header parameters using the same structure as with `Path`, `Query` and `Cookie`.

  )
  fun method(): String = method

  @JvmName("-deprecated_path")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "path"),
    level = DeprecationLevel.ERROR,
  )
  fun path(): String = path

  @JvmName("-deprecated_headers")
  @Deprecated(
    message = "moved to val",
    replaceWith = ReplaceWith(expression = "headers"),
    level = DeprecationLevel.ERROR,
  )

        // IPv4 with port and path
        InetAddress ipv4 = InetAddress.getByName("127.0.0.1");
        assertEquals("http://127.0.0.1:8080/path", IpAddressUtil.buildUrl("http", ipv4, 8080, "/path"));
        assertEquals("http://127.0.0.1:8080/path", IpAddressUtil.buildUrl("http", ipv4, 8080, "path"));

        // IPv4 with port, no path

    }

    /**
     * Returns the path to the pom file for this project.
     * A project is usually read from a file named {@code pom.xml},
     * which contains the {@linkplain #getModel() model} in an XML form.
     * When a custom {@code org.apache.maven.api.spi.ModelParser} is used,
     * the path may point to a non XML file.
     * <p>
     * The POM path is also used to define the {@linkplain #getBasedir() base directory}

<components>
	<include path="convention.xml"/>
	<include path="lastaflute.xml"/>
	<include path="lasta_job.xml"/>

	<include path="fess.xml"/>
	<include path="fess_api.xml"/>
	<include path="fess_cors.xml"/>
	<include path="fess_dict.xml"/>
	<include path="fess_job.xml"/>
	<include path="fess_ldap.xml"/>
	<include path="fess_query.xml"/>
	<include path="fess_rankfusion.xml"/>
	<include path="fess_score.xml"/>

Y todas estas miles de *path operations* pueden ser tan pequeñas como 3 líneas:

{* ../../docs_src/security/tutorial002_an_py310.py hl[30:32] *}

## Resumen { #recap }

Ahora puedes obtener el usuario actual directamente en tu *path operation function*.

Ya estamos a mitad de camino.

 */
public final class CWD implements Supplier<Path> {
    /**
     * Creates instance out of {@link Path}.
     */
    public static CWD create(Path path) {
        return new CWD(CliUtils.getCanonicalPath(path));
    }

    private Path directory;

    private CWD(Path directory) {
        this.directory = directory;
    }

    @Nonnull
    @Override
    public Path get() {
        return directory;
    }

#     ; commonMap = map:{
#         ; path = [relative path to common project from DBFlute client]
#         ; freeGenList = list:{ [env or config or label or message or html] }
#         ; propertiesHtmlList = list:{ [env or config or label or message] }
#     }
#     ; appMap = map:{
#         ; [application name, camel case, initial uncapitalised] = map:{
#             ; path = [relative path to application project from DBFlute client]

 * {@code List<}{@link java.nio.file.Path Path}{@code >},
 * {@code Map<}{@link org.apache.maven.api.PathType PathType}{@code , List<}{@link java.nio.file.Path Path}{@code >>},
 * or {@code Map<}{@link org.apache.maven.api.Dependency Dependency}{@code , }{@link java.nio.file.Path Path}{@code >}.
 *
 * @since 4.0.0
 */
@Experimental
@Documented
@Retention(RetentionPolicy.RUNTIME)

# Body - 欄位 { #body-fields }

就像你可以在「路徑操作函式 (path operation function)」的參數中用 `Query`、`Path` 和 `Body` 宣告額外的驗證與中繼資料一樣，你也可以在 Pydantic 模型中使用 Pydantic 的 `Field` 來宣告驗證與中繼資料。

## 匯入 `Field` { #import-field }

首先，你需要匯入它：

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}


/// warning

請注意，`Field` 是直接從 `pydantic` 匯入的，不像其他（如 `Query`、`Path`、`Body` 等）是從 `fastapi` 匯入。

///

## 宣告模型屬性 { #declare-model-attributes }