Package org.openrdf.sesame.sail

RDF Storage And Inference Layer.

See:
Description

Interface Summary

LiteralIterator	An extension of ValueIterator offering a utility method for retrieving the values as Literals.
NamespaceIterator	An iterator over namespaces that are stored in RDF Sails.
RdfRepository	An extension of the read-only RdfSource interface that adds methods to add data to, and remove data from RDF repositories.
RdfSchemaRepository	An extension of both RdfSchemaSource and RdfRepository.
RdfSchemaSource	An extension of RdfSource offering RDF Schema specific methods.
RdfSource	An extension of the Storage And Inference Layer (Sail) interface that defines methods for read-only RDF-repositories or other sources of information that can be accessed as RDF.
ResourceIterator	An extension of ValueIterator offering a utility method for retrieving the values as Resources.
Sail	An interface for an RDF-based Storage And Inference Layer.
SailChangedEvent	Event object indicating that changes were made to the Sail that sent the event.
SailChangedListener
StackedSail	An interface for Sails that can be stacked on top of other Sails.
StatementIterator	An iterator over statements that are stored in RDF Sails.
ValueIterator	An iterator over Values that are stored in RDF Sails.

Class Summary

Namespace	Object that represents a Namespace.
SailUtil	Defines utility methods for working with Sails.

Exception Summary

SailInitializationException	An exception thrown by Sail.initialize() to indicate that the Sail could not be initialized.
SailInternalException	A runtime exception that can be used to indicate an error or an unexpected situation in an RDF Sail internally.
SailUpdateException	An exception thrown by some methods in RdfRepository to indicate that a requested update operation could not be executed.

Package org.openrdf.sesame.sail Description

RDF Storage And Inference Layer.

The RDF Storage And Inference Layer (RDF Sail) is a collection of interfaces defining an API for RDF repositories. RDF Sail has been designed with the following aims in mind:

• The API must define a minimal interface for storing RDF in, and extracting and deleting RDF from (persistent) repositories.
• The API must abstract from the actual storage mechanism -- be they databases, in-memory (volatile) data structures, files or something else.
• The API should be as scalable as possible.
• The API should be extendable to other RDF-based languages like DAML+OIL.
• The API should support both read-only and read-write repositories properly. A projected use of the read-only interface is for opening up existing databases to the Semantic Web.

The API is split up in several interfaces defining methods for read-only and read-write repositories, as well as methods for RDF-only and RDF Schema repositories. The interfaces are organized like this:

            Sail
              |
              |
          RdfSource
            /   \
           /     \
RdfRepository   RdfSchemaSource
           \     /
            \   /
     RdfSchemaRepository

To accomodate for the scalability, RDF Sail heavily relies on iterators for returning values from the repositories. Iterators exist for returning namespaces, statements, values (literals and resources) and resources.

All methods in the RDF Sail API can throw SailInternalException's (a RuntimeException) to indicate an error or an unexpected situation in the RDF Sail internally (e.g. the database to connect to does not exist).