/**
 * {@link InputStream}用のユーティリティクラスです。
 *
 * @author higa
 */
public abstract class InputStreamUtil {

    /** デフォルトのバッファサイズ */
    private static final int BUF_SIZE = 4096;

    /**
     * {@link FileInputStream}を作成します。
     *
     * @param file
     *            ファイル。{@literal null}であってはいけません
     * @return ファイルから入力する{@link FileInputStream}

The status codes in the 400 range mean that there was an error from the client.

Remember all those **"404 Not Found"** errors (and jokes)?

## Use `HTTPException`

To return HTTP responses with errors to the client you use `HTTPException`.

### Import `HTTPException`

```Python hl_lines="1"

  private static void copy(URL url, File file) throws IOException {
    InputStream in = url.openStream();
    try {
      OutputStream out = new FileOutputStream(file);
      try {
        byte[] buf = new byte[4096];
        for (int read = in.read(buf); read != -1; read = in.read(buf)) {
          out.write(buf, 0, read);
        }
      } finally {
        out.close();
      }
    } finally {
      in.close();

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

Wenn Sie dann zu den URLs unter `/openapi.json`, `/docs` oder `/redoc` gehen, erhalten Sie lediglich einen `404 Not Found`-Fehler, wie:

```JSON
{
    "detail": "Not Found"
}

class Http2Reader(
  /** Creates a frame reader with max header table size of 4096. */
  private val source: BufferedSource,
  private val client: Boolean,
) : Closeable {
  private val continuation: ContinuationSource = ContinuationSource(this.source)
  private val hpackReader: Hpack.Reader =
    Hpack.Reader(
      source = continuation,
      headerTableSizeSetting = 4096,
    )

  @Throws(IOException::class)

    Listener listener;
    synchronized (this) {
      listener = listeners.get(state);
    }

    if (code == null || listener == null) {
      return new MockResponse()
          .setResponseCode(404)
          .setBody("unexpected request");
    }

    try {
      OAuthSession session = slackApi.exchangeCode(code, redirectUrl());
      listener.sessionGranted(session);
    } catch (IOException e) {

pkg syscall (freebsd-386), const ENOTRECOVERABLE Errno
pkg syscall (freebsd-386), const EOWNERDEAD = 96
pkg syscall (freebsd-386), const EOWNERDEAD Errno
pkg syscall (freebsd-386), const EV_DROP = 4096
pkg syscall (freebsd-386), const EV_DROP ideal-int
pkg syscall (freebsd-386), const IPPROTO_MPLS = 137
pkg syscall (freebsd-386), const IPPROTO_MPLS ideal-int
pkg syscall (freebsd-386), const MAP_ALIGNED_SUPER = 16777216

	// relocation in play so the assembled offset should be 0
	JMP	foo(SB)			// 00000050

	JMP	(R4)			// 8000004c
	JMP	1(PC)			// 00040050
	MOVW	$65536, R4		// 04020014
	MOVW	$4096, R4		// 24000014
	MOVV	$65536, R4		// 04020014
	MOVV	$4096, R4		// 24000014
	MOVW	R4, R5			// 85001700
	MOVV	R4, R5			// 85001500
	MOVBU	R4, R5			// 85fc4303
	SUB	R4, R5, R6		// a6101100
	SUBV	R4, R5, R6		// a6901100
	ADD	R4, R5, R6		// a6101000

                }
                if (httpStatusCode == 404) {
                    storeChildUrlsToQueue(urlQueue, getAnchorSet(document.get(fessConfig.getIndexFieldAnchor())));
                    if (!indexingHelper.deleteDocument(searchEngineClient, id)) {
                        logger.debug("Failed to delete 404 document: {}", url);
                    }
                    return false;
                }

    val request =
      Request.Builder()
        .url("https://valid-isrgrootx1.letsencrypt.org/robots.txt")
        .build()
    client.newCall(request).execute().use { response ->
      assertThat(response.code).isEqualTo(404)
      assertThat(response.protocol).isEqualTo(Protocol.HTTP_2)
    }
  }