It is the "**path operation decorator**".

///

You can also use the other operations:

* `@app.post()`
* `@app.put()`
* `@app.delete()`

And the more exotic ones:

* `@app.options()`
* `@app.head()`
* `@app.patch()`
* `@app.trace()`

/// tip

You are free to use each operation (HTTP method) as you wish.

 */
package org.codelibs.fess.app.web.admin.duplicatehost;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.Constants;
import org.codelibs.fess.annotation.Secured;
import org.codelibs.fess.app.pager.DuplicateHostPager;
import org.codelibs.fess.app.service.DuplicateHostService;
import org.codelibs.fess.app.web.CrudMode;

errors.login.failure = Logowanie nie powiodło się.
errors.app.illegal.transition = Nieprawidłowe przejście. Spróbuj ponownie.
errors.app.db.already.deleted = Mogło zostać już usunięte przez inny proces. Spróbuj ponownie.
errors.app.db.already.updated = Mogło zostać już zaktualizowane przez inny proces. Spróbuj ponownie.
errors.app.db.already.exists = Dane już istnieją. Spróbuj ponownie.

The `lifespan` parameter of the `FastAPI` app takes an **async context manager**, so we can pass our new `lifespan` async context manager to it.

{* ../../docs_src/events/tutorial003.py hl[22] *}

## Alternative Events (deprecated) { #alternative-events-deprecated }

/// warning

import org.codelibs.fess.Constants;
import org.codelibs.fess.app.web.CrudMode;
import org.codelibs.fess.app.web.api.ApiResult;
import org.codelibs.fess.app.web.api.ApiResult.ApiDeleteResponse;
import org.codelibs.fess.app.web.api.ApiResult.ApiDocResponse;
import org.codelibs.fess.app.web.api.ApiResult.ApiDocsResponse;
import org.codelibs.fess.app.web.api.ApiResult.ApiResponse;
import org.codelibs.fess.app.web.api.ApiResult.ApiUpdateResponse;

### **FastAPI** app file { #fastapi-app-file }

Let's say you have a file structure as described in [Bigger Applications](bigger-applications.md){.internal-link target=_blank}:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

In the file `main.py` you have your **FastAPI** app:


{* ../../docs_src/app_testing/main.py *}

```

1. Kopiere die Datei `main.py` direkt in das Verzeichnis `/code` (ohne ein Verzeichnis `./app`).

2. Führe Uvicorn aus und weisen es an, das `app`-Objekt von `main` zu importieren (anstatt von `app.main` zu importieren).

Passen Sie dann den Uvicorn-Befehl an, um das neue Modul `main` anstelle von `app.main` zu verwenden, um das FastAPI-Objekt `app` zu importieren.

## Deployment-Konzepte

import org.codelibs.fess.Constants;
import org.codelibs.fess.annotation.Secured;
import org.codelibs.fess.app.pager.DataConfigPager;
import org.codelibs.fess.app.service.DataConfigService;
import org.codelibs.fess.app.service.RoleTypeService;
import org.codelibs.fess.app.web.CrudMode;
import org.codelibs.fess.app.web.base.FessAdminAction;
import org.codelibs.fess.ds.DataStoreFactory;
import org.codelibs.fess.helper.PermissionHelper;

import org.codelibs.fess.Constants;
import org.codelibs.fess.annotation.Secured;
import org.codelibs.fess.app.pager.StopwordsPager;
import org.codelibs.fess.app.service.StopwordsService;
import org.codelibs.fess.app.web.CrudMode;
import org.codelibs.fess.app.web.admin.dict.AdminDictAction;
import org.codelibs.fess.app.web.base.FessAdminAction;
import org.codelibs.fess.dict.stopwords.StopwordsItem;
import org.codelibs.fess.util.ComponentUtil;

<img src="/img/tutorial/generate-clients/image04.png">

The response object will also have autocompletion:

<img src="/img/tutorial/generate-clients/image05.png">

## FastAPI App with Tags { #fastapi-app-with-tags }

In many cases, your FastAPI app will be bigger, and you will probably use tags to separate different groups of *path operations*.