Preserving state in stateless network protocols

摘要

A method and system for preserving state in computers communicating over networks, such as the World Wide Web (WWW) using stateless protocols, e.g., HTTP. State is preserved in a conversation between a client requesting services from a served by performing the service and identifying all continuations (hyperlinks) in an output from the service; recursively embedding the state information in all identified continuations in the output sent to the client. The state information may be embedded and communicated by the server to the client. Alternatively, dynamically downloadable program code may be used to embed the state information at the client. Additional features enable the filtering and/or addition of hyperlinks and data output from the services according to predetermined criteria. State information may be embedded by modifying an identified continuation which is a request for an HTML file, to invoke a CGI converter program with the identified continuation and the state information passed as arguments. State information may also be embedded by modifying an identified continuation which is an invocation to a CGI program with the identified continuation and the state information passed as arguments, and the embedding step is performed by the CGI program. Alternatively, an identified continuation which is an invocation of a CGI program may be modified to invoke a CGI converter program with the identified continuation, an argument counter which indicates a number of arguments associated with the CGI program, and the state information passed as arguments. Here, the embedding is performed by the converter program.