You can add code to be run with the `request`,  before any *path operation* receives it.

And also after the `response` is generated, before returning it.

For example, you could add a custom header `X-Process-Time` containing the time in seconds that it took to process the request and generate a response:

{* ../../docs_src/middleware/tutorial001.py hl[10,12:13] *}

/// tip

#### Docker runtime Known Issues

- Kernel crash with Aufs storage driver on Debian Jessie ([#27885](https://github.com/kubernetes/kubernetes/issues/27885))
  - Consider running the *new* [kubernetes node problem detector](https://github.com/kubernetes/node-problem-detector) to identify this (and other) kernel issues automatically.

- File descriptors are leaked in docker v1.11 ([#275](https://github.com/docker/containerd/issues/275))

        annotations = new ArrayList<>();
        for (Annotation a : classOrMethod.getDeclaredAnnotations()) {
          /*
           * We avoid reflecting on NullMarked because its @Target(..., MODULE) causes problems
           * under JDK 8.
           */
          if (!(a instanceof NullMarked)
              && a.annotationType().isAnnotationPresent(TesterAnnotation.class)) {
            annotations.add(a);
          }

# OpenAPI Callbacks

Podrías crear una API con una *path operation* que podría desencadenar un request a una *API externa* creada por alguien más (probablemente el mismo desarrollador que estaría *usando* tu API).

<font color="#4E9A06">INFO</font>:     Started reloader process [<font color="#34E2E2"><b>2265862</b></font>] using <font color="#34E2E2"><b>WatchFiles</b></font>
<font color="#4E9A06">INFO</font>:     Started server process [<font color="#06989A">2265873</font>]
<font color="#4E9A06">INFO</font>:     Waiting for application startup.

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.artifact.repository.metadata;

/**
 * Problem storing the repository metadata in the local repository.
 *
 */
public class RepositoryMetadataStoreException extends Exception {
    public RepositoryMetadataStoreException(String message) {
        super(message);
    }

 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.artifact.repository.metadata;

/**
 * Problem storing the repository metadata in the local repository.
 *
 */
@Deprecated
public class RepositoryMetadataReadException extends Exception {
    public RepositoryMetadataReadException(String message) {

 * beyond the standard ones provided by Maven. Implementations of this interface will be discovered
 * through the Java ServiceLoader mechanism and their provided languages will be available
 * throughout the Maven build process.
 * <p>
 * Example usage:
 * <pre>
 * public class CustomLanguageProvider implements LanguageProvider {
 *     public Collection&lt;Language&gt; provides() {
 *         return Collections.singleton(language("kotlin"));

    - Kernel crash with Aufs storage driver on Debian Jessie ([#27885]((https://github.com/kubernetes/kubernetes/issues/27885))
      which can be identified by the [node problem detector](http://kubernetes.io/docs/admin/node-problem/)
    - Leaked File descriptors ([#275](https://github.com/docker/containerd/issues/275))
    - Additional memory overhead per container ([#21737]((https://github.com/docker/docker/issues/21737))

Bevorzugen Sie die `Annotated`-Version, falls möglich.

///

```Python hl_lines="7"
{!> ../../docs_src/path_params_numeric_validations/tutorial002.py!}
```

////

Aber bedenken Sie, dass Sie dieses Problem nicht haben, wenn Sie `Annotated` verwenden, da Sie nicht die Funktions-Parameter-Defaultwerte für `Query()` oder `Path()` verwenden.

{* ../../docs_src/path_params_numeric_validations/tutorial002_an_py39.py hl[10] *}