If an incoming request does not validate correctly then a `400` response will be sent.

## `GZipMiddleware`

Handles GZip responses for any request that includes `"gzip"` in the `Accept-Encoding` header.

The middleware will handle both standard and streaming responses.

{* ../../docs_src/advanced_middleware/tutorial003.py hl[2,6] *}

The following arguments are supported:

 */
@Named
@Singleton
public class DefaultExceptionHandler implements ExceptionHandler {
    @Override
    public ExceptionSummary handleException(Throwable exception) {
        return handle("", exception);
    }

    private ExceptionSummary handle(String message, Throwable exception) {
        String reference = getReference(Collections.newSetFromMap(new IdentityHashMap<>()), exception);

        List<ExceptionSummary> children = null;

In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

### `shutdown` event

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

///

We can also use this same approach to access the request body in an exception handler.

All we need to do is handle the request inside a `try`/`except` block:

{* ../../docs_src/custom_request_and_route/tutorial002.py hl[13,15] *}

If an exception occurs, the`Request` instance will still be in scope, so we can read and make use of the request body when handling the error:

## Create a task function

Create a function to be run as the background task.

It is just a standard function that can receive parameters.

It can be an `async def` or normal `def` function, **FastAPI** will know how to handle it correctly.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

     */
    @Deprecated
    public static DefaultRepositorySystemSession newSession() {
        DefaultRepositorySystemSession session = new DefaultRepositorySystemSession(h -> false); // no close handle
        MavenSessionBuilderSupplier builder = new MavenSessionBuilderSupplier();
        session.setDependencyTraverser(builder.getDependencyTraverser());

        return "Secure console password prompt";
    }

    @Override
    public Optional<String> configTemplate() {
        return Optional.empty();
    }

    @Override
    public String handle(String config) throws SecDispatcherException {
        if (NAME.equals(config)) {
            try {
                return prompter.promptForPassword("Enter the master password: ");
            } catch (PrompterException e) {

          <version>1.0.0</version>
          <description>How to handle downloading of releases from this repository</description>
          <association>
            <type>RepositoryPolicy</type>
          </association>
        </field>
        <field>
          <name>snapshots</name>
          <version>1.0.0</version>
          <description>How to handle downloading of snapshots from this repository</description>

You can probably right-click each link and select an option similar to `Save link as...`.

**Swagger UI** uses the files:

* <a href="https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui-bundle.js" class="external-link" target="_blank">`swagger-ui-bundle.js`</a>
* <a href="https://cdn.jsdelivr.net/npm/swagger-ui-dist@5/swagger-ui.css" class="external-link" target="_blank">`swagger-ui.css`</a>

And **ReDoc** uses the file:

    if depends is not None and depends.dependency is None:
        # Copy `depends` before mutating it
        depends = copy(depends)
        depends.dependency = type_annotation

    # Handle non-param type annotations like Request
    if lenient_issubclass(
        type_annotation,
        (
            Request,
            WebSocket,
            HTTPConnection,
            Response,