assertEquals(0, ((WebAuthenticationConfig[]) initParamMap.get(HcHttpClient.AUTHENTICATIONS_PROPERTY)).length);
        assertTrue(Boolean.valueOf(initParamMap.get("robotsTxtEnabled").toString()).booleanValue());
    }

    @Test
    public void test_initializeClientFactoryWithConfigParameter() {
        final Map<String, String> systemPropMap = new HashMap<>();

    └── 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

Pattern-based client selection (from `crawler/client.xml`):
- `http:.*`, `https:.*` → SwitchableHttpClient