HTTP on Symbian OS

核心提示：PurposeThe HTTP Client API provides a client interface for Internet applications to use the HTTP Protocol for communication with HTTP servers on the Internet. U

Purpose

The HTTP Client API provides a client interface for Internet applications to use the HTTP Protocol for communication with HTTP servers on the Internet. Using the API correctly enables the application to be a conditionally HTTP 1.1 compliant client, as defined in RFC 2616

Please be noted that this HTTP Client API support starts from Symbian OS 7.0s and forward. In another word, if you develop for devices such as Nokia N-Gage QD, you will do HTTP client business yourself from socket scratch.

Architectural relationships

The HTTP Client architecture provides a generalised mechanism for HTTP-like protocols that operate over various transports. Using a single API, a client can choose an HTTP protocol, encoding and transport. The client is not expected to implement anything else specific to those choices in its own code. The default operation provides plain-text HTTP (as defined in RFC 2616) operating over a TCP/IP connection. This transport pipelines requests by default.

Description

There are five key concepts used in the API: sessions, transactions, headers, data suppliers and filters.

Sessions

A session encapsulates the client's HTTP activity over the duration of the client's execution. Usually, one session is used at a time; however the client may use several concurrently if desired. Each session has an associated set of properties, which define the HTTP protocol, encoding and transport that are used. Those properties apply to all HTTP transactions carried out within the life of that session. The session also has an associated set of filters, that provide additional automatic behaviours on the client's behalf.

The session class is provided by RHTTPSession.

Transactions

A transaction represents an interaction between the HTTP client and an HTTP origin server. Normally a transaction consists of a single exchange of messages