}
    }

    /**
     * Sets the connection timeout in milliseconds.
     *
     * @param connectionTimeout The connection timeout
     */
    public void setConnectionTimeout(final Integer connectionTimeout) {
        this.connectionTimeout = connectionTimeout;
    }

    /**
     * Sets the maximum total number of connections.
     *

HcHttpClient (abstract base class)
    ├── Hc4HttpClient
    └── Hc5HttpClient
```

Switch via system property: `-Dfess.crawler.http.client=hc4` or `hc5` (default)

**Key Properties**: `connectionTimeout`, `soTimeout`, `proxyHost`, `proxyPort`, `userAgent`, `robotsTxtEnabled`, `ignoreSslCertificate`, `maxTotalConnection`, `defaultMaxConnectionPerRoute`

### CrawlerClientFactory

                        if (httpConfigurationAll != null) {
                            connectTimeoutXml = httpConfigurationAll.getChild("connectionTimeout", false);
                            if (connectTimeoutXml != null) {
                                connectTimeout = Integer.parseInt(connectTimeoutXml.getValue());

    // Confirm that the connection was reused.
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(0)
    assertThat(server.takeRequest().exchangeIndex).isEqualTo(1)
  }

  @Test
  fun connectionTimeout() {
    server.enqueue(
      MockResponse
        .Builder()
        .body("A")
        .bodyDelay(1, TimeUnit.SECONDS)
        .build(),
    )
    val client1 =
      client