### HTTP Client Architecture

```
SwitchableHttpClient (extends FaultTolerantClient)
    ├── Hc5HttpClient (default) - Apache HttpComponents 5.x
    └── Hc4HttpClient (fallback) - Apache HttpComponents 4.x

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

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

	<include path="crawler/contentlength.xml" />
	<include path="crawler/mimetype.xml" />

	<!-- HC5 (Default) -->
	<component name="internalHttpClient" class="org.codelibs.fess.crawler.client.http.Hc5HttpClient"
		instance="prototype">
		<property name="connectionTimeout">15000</property>
		<property name="soTimeout">30000</property>
	</component>

	<!-- HC4 (Alternative - for backward compatibility) -->