An introduction to the Web Services Policy Language (WSPL)

摘要

The Web Services Policy Language (WSPL) is suitable for specifying a wide range of policies, including authorization, quality-of-service, quality-of-protection, reliable messaging, privacy, and application-specific service options. WSPL is of particular interest in several respects. It supports merging two policies, resulting in a single policy that satisfies the requirements of both, assuming such a policy exists. Policies can be based on comparisons other than equality, allowing policies to depend on fine-grained attributes such as time of day, cost, or network subnet address. By using standard data types and functions for expressing policy parameters, a standard policy engine can support any policy. The syntax is a strict subset of the OASIS eXtensible Access Control Markup Language (XACML) Standard. WSPL has been implemented, and is under consideration as a standard policy language for use with Web services.