# Background Tasks { #background-tasks }

You can define background tasks to be run *after* returning a response.

This is useful for operations that need to happen after a request, but that the client doesn't really have to be waiting for the operation to complete before receiving the response.

This includes, for example:

* Email notifications sent after performing an action:

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * Provides classes for Maven plugin descriptors that define plugin metadata, configuration,
 * and execution parameters. These descriptors are typically stored in plugin.xml files
 * within the META-INF/maven directory of plugin JARs.
 *
 * @since 4.0.0
 */

{* ../../docs_src/query_params_str_validations/tutorial003_an_py310.py hl[10] *}

## Add regular expressions { #add-regular-expressions }

You can define a <abbr title="A regular expression, regex or regexp is a sequence of characters that define a search pattern for strings.">regular expression</abbr> `pattern` that the parameter should match:

{* ../../docs_src/query_params_str_validations/tutorial004_an_py310.py hl[11] *}

# Security Tools

When you need to declare dependencies with OAuth2 scopes you use `Security()`.

But you still need to define what is the dependable, the callable that you pass as a parameter to `Depends()` or `Security()`.

There are multiple tools that you can use to create those dependables, and they get integrated into OpenAPI so they are shown in the automatic docs UI, they can be used by automatically generated clients and SDKs, etc.

    @Test
    void testToString() {
        // Create a mock DfsReferralData object
        DfsReferralData mockData = mock(DfsReferralData.class);
        String expectedToString = "Mock DfsReferralData";

        // Define the behavior of the mock's toString() method
        when(mockData.toString()).thenReturn(expectedToString);

        // Create a DfsReferral instance with the mock data

 *  JQUERY-FORM-VALIDATOR
 *
 *  @version 2.3.77
 *  @website http://formvalidator.net/
 *  @author Victor Jonsson, http://victorjonsson.se
 *  @license MIT
 */

import org.lastaflute.web.validation.Required;

/**
 * Form for uploading search request files to the Fess search engine.
 * This form is used in the admin interface to upload search request configuration files
 * that define search behaviors and request handling.
 */
public class UploadForm {

    /**
     * The multipart file containing the search request configurations to be uploaded.

# `UploadFile` class

You can define *path operation function* parameters to be of the type `UploadFile` to receive files from the request.

You can import it directly from `fastapi`:

```python
from fastapi import UploadFile
```

::: fastapi.UploadFile
    options:
        members:
            - file
            - filename
            - size
            - headers
            - content_type
            - read

Sehen wir uns nun an, wie Sie damit eine benutzerdefinierte Response zurückgeben können.

Nehmen wir an, Sie möchten eine <a href="https://en.wikipedia.org/wiki/XML" class="external-link" target="_blank">XML</a>-Response zurückgeben.

Sie könnten Ihren XML-Inhalt als String in eine `Response` einfügen und sie zurückgeben:

/**
 * Form class for editing mapping dictionary entries in the admin interface.
 * This form extends CreateForm to include fields necessary for updating existing mapping dictionary entries.
 * Mapping dictionaries define field mappings and transformations during the indexing process.
 *
 */
public class EditForm extends CreateForm {

    /**
     * Creates a new EditForm instance.
     */
    public EditForm() {