http://hc.apache.org/

http://hc.apache.org/httpcomponents-asyncclient-4.1.x/index.html

http://hc.apache.org/httpcomponents-core-ga/tutorial/html/index.html

<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpclient</artifactId>
  <version>4.5.13</version>
</dependency>

<dependency>
  <groupId>org.apache.httpcomponents</groupId>
  <artifactId>httpasyncclient</artifactId>
  <version>4.1.4</version>
</dependency>

org.apache.httpcomponents