public static final String AUTH_SCHEME_PROVIDERS_PROPERTY = "authSchemeProviders";

    /** Property name for ignore SSL certificate setting */
    public static final String IGNORE_SSL_CERTIFICATE_PROPERTY = "ignoreSslCertificate";

    /** Property name for default maximum connections per route setting */
    public static final String DEFAULT_MAX_CONNECTION_PER_ROUTE_PROPERTY = "defaultMaxConnectionPerRoute";

    }

    /**
     * Sets whether to ignore SSL certificate validation.
     *
     * @param ignoreSslCertificate True to ignore SSL certificate validation, false otherwise
     */
    public void setIgnoreSslCertificate(final boolean ignoreSslCertificate) {
        this.ignoreSslCertificate = ignoreSslCertificate;
    }

```

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