return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		read := r.Method == http.MethodGet || r.Method == http.MethodHead
		// Re-direction is handled specifically for browser requests.
		if !guessIsHealthCheckReq(r) && guessIsBrowserReq(r) && read && globalBrowserRedirect {
			// Fetch the redirect location if any.
			if u := getRedirectLocation(r); u != nil {
				// Employ a temporary re-direct.

<img src="/img/tutorial/sub-applications/image02.png">

If you try interacting with any of the two user interfaces, they will work correctly, because the browser will be able to talk to each specific app or sub-app.

### Technical Details: `root_path` { #technical-details-root-path }

	// accordingly. Client receives a HTTP error for invalid/unsupported
	// signatures.
	//
	// Validates all incoming requests to have a valid date header.
	setAuthMiddleware,
	// Redirect some pre-defined browser request paths to a static location
	// prefix.
	setBrowserRedirectMiddleware,
	// Adds 'crossdomain.xml' policy middleware to serve legacy flash clients.
	setCrossDomainPolicyMiddleware,

    assertFalse(Ascii.equalsIgnoreCase("@", "`"));
    assertFalse(Ascii.equalsIgnoreCase("[", "{"));
  }

  @GwtIncompatible // String.toUpperCase() has browser semantics
  public void testEqualsIgnoreCaseUnicodeEquivalence() {
    // Note that it's possible in future that the JDK's idea to toUpperCase() or equalsIgnoreCase()

    assertFalse(Ascii.equalsIgnoreCase("@", "`"));
    assertFalse(Ascii.equalsIgnoreCase("[", "{"));
  }

  @GwtIncompatible // String.toUpperCase() has browser semantics
  public void testEqualsIgnoreCaseUnicodeEquivalence() {
    // Note that it's possible in future that the JDK's idea to toUpperCase() or equalsIgnoreCase()

{* ../../docs_src/query_params/tutorial005.py hl[6:7] *}

Hier ist `needy` ein erforderlicher Query-Parameter vom Typ `str`.

Wenn Sie in Ihrem Browser eine URL wie:

```
http://127.0.0.1:8000/items/foo-item
```

... öffnen, ohne den benötigten Parameter `needy`, dann erhalten Sie einen Fehler wie den folgenden:

```JSON
{
  "detail": [

因此， （运行在浏览器中的）前端会尝试访问 `/openapi.json`，但没有办法获取 OpenAPI 概图。

这是因为应用使用了以 `/api/v1` 为路径前缀的代理，前端要从 `/api/v1/openapi.json`  中提取 OpenAPI 概图。

```mermaid
graph LR

browser("Browser")
proxy["Proxy on http://0.0.0.0:9999/api/v1/app"]
server["Server on http://127.0.0.1:8000/app"]

browser --> proxy
proxy --> server
```

/// tip | 提示

IP `0.0.0.0` 常用于指程序监听本机或服务器上的所有有效 IP。

///

  private var failFastResponse: MockResponse? = null

  @Throws(InterruptedException::class)
  override fun dispatch(request: RecordedRequest): MockResponse {
    // To permit interactive/browser testing, ignore requests for favicons.
    val requestLine = request.requestLine
    if (requestLine == "GET /favicon.ico HTTP/1.1") {
      logger.info("served $requestLine")

Header <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">mittels des Präfix 'X-'</a> hinzugefügt werden können.

Wenn Sie jedoch benutzerdefinierte Header haben, die ein Client in einem Browser sehen können soll, müssen Sie diese zu Ihren CORS-Konfigurationen hinzufügen (weitere Informationen finden Sie unter [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), unter Verwendung des Parameters `expose_headers`,...

that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the 'X-' prefix</a>.

But if you have custom headers that you want a client in a browser to be able to see, you need to add them to your CORS configurations (read more in [CORS (Cross-Origin Resource Sharing)](../tutorial/cors.md){.internal-link target=_blank}), using the parameter `expose_headers` documented in <a href="https://www....