Android APIs
Added in API level 1
package

org.apache.http.client

The API for client-side HTTP communication and entry point to the HttpClient module.

Interfaces

AuthenticationHandler  
CookieStore Abstract cookie store. 
CredentialsProvider Abstract credentials provider. 
HttpClient Interface for an HTTP client. 
HttpRequestRetryHandler A handler for determining if an HttpRequest should be retried after a recoverable exception during execution. 
RedirectHandler A handler for determining if an HTTP request should be redirected to a new location in response to an HTTP response received from the target server. 
RequestDirector A client-side request director. 
ResponseHandler<T> Handler that encapsulates the process of generating a response object from a HttpResponse
UserTokenHandler A handler for determining if the given execution context is user specific or not. 

Exceptions

CircularRedirectException Signals a circular redirect 
ClientProtocolException Signals an error in the HTTP protocol. 
HttpResponseException Signals a non 2xx HTTP response. 
NonRepeatableRequestException Signals failure to retry the request due to non-repeatable request entity. 
RedirectException Signals violation of HTTP specification caused by an invalid redirect