org.apache.commons.httpclient.HttpClient 与 org.apache.http.client.HttpClient区别
HttpClient was started in 2001 as a subproject of the Jakarta Commons, based on code developed by the Jakarta Slide project. It was promoted out of the Commons in 2004, graduating to a separate Jakarta project. In 2005, the HttpComponents project at Jakarta was created, with the task of developing a successor to HttpClient 3.x and to maintain the existing codebase until the new one is ready to take over. The Commons project, cradle of HttpClient, left Jakarta in 2007 to become an independent Top Level Project. Later in the same year, the HttpComponents project also left Jakarta to become an independent Top Level Project, taking the responsibility for maintaining HttpClient with it.