如果有任何后台任务（会在[后台任务](background-tasks.md)一节中介绍，你稍后会看到），它们会在所有中间件之后运行。

///

## 创建中间件 { #create-a-middleware }

要创建中间件，你可以在函数的顶部使用装饰器 `@app.middleware("http")`。

中间件函数会接收：

* `request`。
* 一个函数 `call_next`，它会把 `request` 作为参数接收。
    * 这个函数会把 `request` 传递给相应的*路径操作*。
    * 然后它返回由相应*路径操作*生成的 `response`。
* 在返回之前，你可以进一步修改 `response`。

{* ../../docs_src/middleware/tutorial001_py310.py hl[8:9,11,14] *}

/// tip

import org.codelibs.fess.app.web.api.admin.BaseSearchBody;

/**
 * Search request body for request header administration API.
 */
public class SearchBody extends BaseSearchBody {

    /**
     * Default constructor.
     */
    public SearchBody() {
        super();
    }

    /** Request header configuration ID */
    public String id;

         * direct dependencies from the request will be merged with the direct dependencies from the root dependency's
         * artifact descriptor, giving higher priority to the dependencies from the request.
         *
         * @param dependencies the direct dependencies, may be {@code null}
         * @return this request for chaining, never {@code null}
         */

     * @param request The HTTP servlet request containing authentication data.
     * @return The login credential or null if processing fails.
     */
    protected LoginCredential processAuthenticationData(final HttpServletRequest request) {
        final StringBuilder urlBuf = new StringBuilder(request.getRequestURL());
        final String queryStr = request.getQueryString();
        if (queryStr != null) {

        // search

    }

    /**
     * Get the permissions.
     * @param request The request.
     * @return The permissions.
     */
    public OptionalEntity<Set<String>> getPermissions(final HttpServletRequest request) {
        final String token = ComponentUtil.getAccessTokenHelper().getAccessTokenFromRequest(request);
        if (StringUtil.isNotBlank(token)) {
            return accessTokenBhv.selectEntity(cb -> {

Para criar um middleware, use o decorador `@app.middleware("http")` logo acima de uma função.

A função middleware recebe:

* A `request`.
* Uma função `call_next` que receberá o `request` como um parâmetro.
    * Esta função passará a `request` para a *operação de rota* correspondente.
    * Então ela retorna a `response` gerada pela *operação de rota* correspondente.

     */
    public void setSearchQuery(final String searchQuery) {
        this.searchQuery = searchQuery;
    }

    /**
     * Sets the timestamp when the search request was made.
     *
     * @param requestedTime The request timestamp
     */
    public void setRequestedTime(final long requestedTime) {
        this.requestedTime = requestedTime;
    }

    /**

	"github.com/minio/minio/internal/logger"
	"github.com/minio/pkg/v3/policy"
)

// KMSStatusHandler - GET /minio/kms/v1/status
func (a kmsAPIHandlers) KMSStatusHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "KMSStatus")
	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
	objectAPI, _ := validateAdminReq(ctx, w, r, policy.KMSStatusAction)
	if objectAPI == nil {
		return
	}

        }
    }

    @Override
    protected void service(final HttpServletRequest request, final HttpServletResponse response) throws ServletException, IOException {
        Address dc;
        final boolean offerBasic = this.enableBasic && (this.insecureBasic || request.isSecure());
        final String msg = request.getHeader("Authorization");

* `"request"`: dependency'yi request'i işleyen *path operation function* çalışmadan önce başlat (`"function"` kullanımına benzer), ancak response client'a geri gönderildikten **sonra** sonlandır. Yani dependency fonksiyonu, **request** ve response döngüsünün **etrafında** çalıştırılır.

Belirtilmezse ve dependency `yield` kullanıyorsa, varsayılan olarak `scope` `"request"` olur.