class Settings(BaseSettings):
    openapi_url: str = "/openapi.json"


settings = Settings()

app = FastAPI(openapi_url=settings.openapi_url)


@app.get("/")
def root():

        byte[] data = "Hello World".getBytes();
        InputStream underlyingStream = new ByteArrayInputStream(data);
        IgnoreCloseInputStream stream = new IgnoreCloseInputStream(underlyingStream);

        byte[] buffer = new byte[5];
        int bytesRead = stream.read(buffer);

        assertEquals(5, bytesRead);
        assertEquals("Hello", new String(buffer));
    }

    val request =
      Request
        .Builder()
        .url("https://square.com/".toHttpUrl())
        .tag<String>("hello")
        .tag<Int>(5)
        .build()
    assertThat(request.toString()).isEqualTo(
      "Request{method=GET, url=https://square.com/, tags={" +
        "class kotlin.String=hello, " +
        "class kotlin.Int=5" +
        "}}",
    )
  }

  @Test
  fun gzip() {

	c.Assert(response.ContentLength, int64(len([]byte("hello world"))))
	var buffer2 bytes.Buffer
	// retrieve the contents of response body.
	n, err := io.Copy(&buffer2, response.Body)
	c.Assert(err, nil)
	c.Assert(n, int64(len([]byte("hello world"))))
	// asserted the contents of the fetched object with the expected result.
	c.Assert(true, bytes.Equal(buffer2.Bytes(), []byte("hello world")))

client = TestClient(app)


def test_path_operation():
    response = client.get("/headers-and-object/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Hello World"}

    }

    @Test
    public void testGetContentAsStringWithCache() throws IOException {
        CurlResponse response = new CurlResponse();
        response.setEncoding("UTF-8");
        String testContent = "Hello, World!";
        byte[] data = testContent.getBytes("UTF-8");
        ContentCache cache = new ContentCache(data);
        response.setContentCache(cache);

        String content = response.getContentAsString();

client = TestClient(app)


def test_path_operation():
    response = client.get("/headers/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Hello World"}
    assert response.headers["X-Cat-Dog"] == "alone in the world"

        when(mockFileHandle.acquire()).thenReturn(mockFileHandle);

        when(mockFile.openUnshared(anyInt(), anyInt(), anyInt(), anyInt(), anyInt())).thenReturn(mockFileHandle);

        byte[] data = "Hello World".getBytes();
        when(mockTreeHandle.send(any(Smb2WriteRequest.class), any())).thenReturn(mockWriteResponse);
        when(mockWriteResponse.getCount()).thenReturn(data.length);

////

## Headings { #headings }

//// tab | Test

### Develop a webapp - a tutorial { #develop-a-webapp-a-tutorial }

Hello.

### Type hints and -annotations { #type-hints-and-annotations }

Hello again.

### Super- and subclasses { #super-and-subclasses }

Hello again.

////

//// tab | Info

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

</div>

返回的响应如下：

```JSON
{
    "message": "Hello World",
    "root_path": "/api/v1"
}
```

### 在 FastAPI 应用里设置 `root_path`

还有一种方案，如果不能提供 `--root-path` 或等效的命令行选项，则在创建 FastAPI 应用时要设置 `root_path` 参数。