{* ../../docs_src/events/tutorial003_py39.py hl[1,13] *}

A **context manager** in Python is something that you can use in a `with` statement, for example, `open()` can be used as a context manager:

```Python
with open("file.txt") as file:
    file.read()
```

In recent versions of Python, there's also an **async context manager**. You would use it with `async with`:

```Python
async with lifespan(app):
    await do_stuff()
```

Um **gerenciador de contexto** em Python é algo que você pode usar em uma declaração `with`, por exemplo, `open()` pode ser usado como um gerenciador de contexto:

```Python
with open("file.txt") as file:
    file.read()
```

Em versões mais recentes do Python, há também um **gerenciador de contexto assíncrono**. Você o usaria com `async with`:

```Python
async with lifespan(app):
    await do_stuff()

          .build(),
      ).build()

  fun run() {
    val request =
      Request
        .Builder()
        .url("https://publicobject.com/robots.txt")
        .build()

    client.newCall(request).execute().use { response ->
      if (!response.isSuccessful) throw IOException("Unexpected code $response")

        .addEqualityGroup(
            new ResourceInfo(FILE, "a/b/c.txt", getClass().getClassLoader()),
            new ResourceInfo(FILE, "a/b/c.txt", getClass().getClassLoader()))
        .addEqualityGroup(new ResourceInfo(FILE, "x.txt", getClass().getClassLoader()))
        .testEquals();
  }

  @AndroidIncompatible // Android forbids null parent ClassLoader

      .addNetworkInterceptor(CHECK_HANDSHAKE_INTERCEPTOR)
      .build();

  public void run() throws Exception {
    Request request = new Request.Builder()
        .url("https://publicobject.com/helloworld.txt")
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

<div class="termy">

```console
$ uv pip install -r requirements.txt
---> 100%
```

</div>

////

/// details | 關於 `requirements.txt`

一個包含一些套件的 `requirements.txt` 檔案看起來應該是這樣的：

```requirements.txt
fastapi[standard]==0.113.0
pydantic==2.8.0
```

///

## 執行程式

在啟用虛擬環境後，你可以執行你的程式，它將使用虛擬環境中的 Python 和你在其中安裝的套件。

<div class="termy">

```console
$ uv pip install -r requirements.txt
---> 100%
```

</div>

////

/// details | 关于 `requirements.txt`

一个包含一些软件包的 `requirements.txt` 文件看起来应该是这样的：

```requirements.txt
fastapi[standard]==0.113.0
pydantic==2.8.0
```

///

## 运行程序

在你激活虚拟环境后，你可以运行你的程序，它将使用虚拟环境中的 Python 和你在其中安装的软件包。

 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.crawler.exception;

/**
 * RobotsTxtException is an exception class that represents an error related to robots.txt processing during web crawling.
 * It extends CrawlerSystemException and provides constructors to create instances with a message and/or a cause.
 *
 */
public class RobotsTxtException extends CrawlerSystemException {

public final class SynchronousGet {
  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    Request request = new Request.Builder()
        .url("https://publicobject.com/helloworld.txt")
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

    OkHttpDebugLogging.enable("org.bouncycastle.jsse")
    platform.assumeBouncyCastle()
  }

  @Test
  fun testMozilla() {
    assumeNetwork()

    val request = Request.Builder().url("https://mozilla.org/robots.txt").build()

    client.newCall(request).execute().use {
      assertThat(it.protocol).isEqualTo(Protocol.HTTP_2)
      assertThat(it.handshake!!.tlsVersion).isEqualTo(TlsVersion.TLS_1_3)
    }
  }