HttpComponents Core 4.4.6 发布了，这是一个修复版本，修复了4.4.5 的许多bug。
更新内容：
NIO connection pool incorrectly reports the number of pending connections per individual route.
moved expensive connection validation code outside the pool lock.
ConnectionConfig#copy() does not copy every field.
Handling of HEAD responses without payload headers.
correct character encoding default for application/json.
SSLIOSession#close to handle CancelledKeyException.
SSL i/o sessions to use a finite timeout for SSL shutdown handshake when closing.
HttpAsyncResponseConsumer#onEntityEnclosed is triggered for HEAD responses.
Fixed MIME type validation in ContentType#create(String) method.
下载地址：
HttpComponents 也就是以前的httpclient项目，可以用来提供高效的、最新的、功能丰富的支持 HTTP 协议的客户端/服务器编程工具包，并且它支持 HTTP 协议最新的版本和建议。不过现在的 HttpComponents 包含多个子项目，有：
HttpComponents Core
HttpComponents Client
HttpComponents AsyncClient
Commons HttpClient