Android APIs
Added in API level 1
package

org.apache.http

The core interfaces and classes of the HTTP components. These deal with the fundamental things required for using the HTTP protocol, such as representing a message including it's headers and optional entity, and connections over which messages are sent. In order to prepare messages before sending or after receiving, there are interceptors for requests and responses.

Interfaces

ConnectionReuseStrategy Interface for deciding whether a connection should be kept alive. 
FormattedHeader An HTTP header which is already formatted. 
Header Represents an HTTP header field. 
HeaderElement One element of an HTTP header value. 
HeaderElementIterator A type-safe iterator for HeaderElement objects. 
HeaderIterator A type-safe iterator for Header objects. 
HttpClientConnection An HTTP connection for use on the client side. 
HttpConnection A generic HTTP connection, useful on client and server side. 
HttpConnectionMetrics The point of access to the statistics of an HttpConnection. 
HttpEntity An entity that can be sent or received with an HTTP message. 
HttpEntityEnclosingRequest A request with an entity. 
HttpInetConnection An HTTP connection over the Internet Protocol (IP). 
HttpMessage A generic HTTP message. 
HttpRequest An HTTP request. 
HttpRequestFactory A factory for HttpRequest objects. 
HttpRequestInterceptor Processes a request. 
HttpResponse An HTTP response. 
HttpResponseFactory A factory for HttpResponse objects. 
HttpResponseInterceptor Processes a response. 
HttpServerConnection An HTTP connection for use on the server side. 
HttpStatus Constants enumerating the HTTP status codes. 
NameValuePair A simple class encapsulating an attribute/value pair. 
ReasonPhraseCatalog Interface for obtaining reason phrases for HTTP status codes. 
RequestLine The first line of an HttpRequest. 
StatusLine Represents a status line as returned from a HTTP server. 
TokenIterator An iterator for String tokens. 

Classes

HttpHost Holds all of the variables needed to describe an HTTP connection to a host. 
HttpVersion Represents an HTTP version, as specified in RFC 2616. 
ProtocolVersion Represents a protocol version, as specified in RFC 2616. 

Exceptions

ConnectionClosedException Indicates that a connection has been closed. 
HttpException Signals that an HTTP exception has occurred. 
MalformedChunkCodingException Signals a malformed chunked stream. 
MethodNotSupportedException Indicates that an HTTP method is not supported. 
NoHttpResponseException

Signals that the target server failed to respond with a valid HTTP response. 

ParseException Indicates a parse error. 
ProtocolException Signals that an HTTP protocol violation has occurred. 
UnsupportedHttpVersionException Indicates an unsupported version of the HTTP protocol.