Transcript Validation of Semantics in XML Dmitry Bragin under

Validation of Semantics in XML
Dmitry Bragin under supervision of David Chadwick
Context
PERMIS software uses pure Java code for
validation of the XML policies. Integrating
an XML Schema Validator into the code will
allow us to move a significant number of
the semantic checks from the Java code
into the schema document and Validator.
Along with the standard parent-child
relationships the schema handles aspects
such as data type checks and reference
relationships. The schema has ways for the
policy content to be user extendible by
providing a framework for polymorphism
and inheritance.
PERMIS is modular Java software that
makes access control decisions and
provides tools for managing policies,
role assignments and delegations
between users.
Fig. 1 – Traditional architecture of
an XML-enabled Application
Fig. 2 – Solution to handling XML
data that maintains the separation of
concerns principle
Problems with this
architecture



Maintainability
Scalability
Extensibility
XML Parsers/Validators
Schema provides:
•
OO style Inheritance with abstract and
final types.
•
Polymorphism
•
User Extensibility

Xerces, the most commonly used parser,
can be used as Schema Validator

Migration to Xerces or any other
alternative is very easy provided that the
code uses JAXP to access the
functionality

Xerces is available on most platforms
and Programming languages