Package com.hp.hpl.jena.graph.query

Defines the graph-level Query classes, allowing multi-pattern query over arbitrary graphs.

See:
Description

Interface Summary

BindingQueryPlan	A BindingQueryPlan is something that can run executeBindings() to get back an ExtendedIterator over Domains, ie, Lists.
Expression	Expression - the interface for expressions that is expected by Query for constraints.
ExpressionFunctionURIs	ExpressionFunctionURIs: constants expressing the URIs for functions that may be recognised or generated by expression constructors and analysers.
IndexValues	IndexValues: something that when supplied with a non-negative integer, returns a value.
PatternCompiler	A PatternCompiler is some class that knows how to handle fixed Node values, binding and bound occurences of variables, and wildcards.
PatternLiteral	PatternLiteral - an interface for pattern literals recognised by Rewrite.
Pipe	A Pipe is anything that can be used to get and put Domain objects; it can be closed, and it can be tested for whether more elements are available.
QueryHandler	a QueryHandler handles queries on behalf of a graph.
TreeQueryPlan
TripleSorter	Interface for things that can sort triples (for optimising queries).
Valuator	Valuator - an interface for things that evaluate to some value, given a binding of variable (inexes) to values.
VariableIndexes	VariableIndexes: a mapping from variable names to their offsets in some table of variable values.
VariableValues	The interface that allows the values of variables in expressions to be found.

Class Summary

Bind	A binding instance of a variable.
Bound	An element which represents an already-bound variable.
BufferPipe	This class is a pipe between query threads, implemented as a bounded buffer.
BufferPipe.Finished
ConstraintStage	A ConstraintStage implements the constraint evaluation part of a query.
Domain	A Domain is an answer to a Binding query.
Dyadic	A base class for dyadic expressions with a built-in Valuator; subclasses must define an evalObject or evalBool method which will be supplied with the evaluated operands.
Element	An Element of a matching triple.
Expression.Application	An abstract base class for apply nodes; subclasses implement getFun(), argCount(), and getArg().
Expression.Base	An abstract base class for Expressions; over-ride as appropriate.
Expression.BoolConstant	Base class used to implement TRUE and FALSE.
Expression.Constant	An abstract base class for literal nodes; subclasses implement getValue().
Expression.Fixed	A concrete class for representing fixed constants; each instance can hold a separate value and its valuator returns that value.
Expression.Util	Utility methods for Expressions, captured in a class because they can't be written directly in the interface.
Expression.Valof	Valof provides an implementation of VariableValues which composes the "compile-time" VariableIndexes map with the "run-time" IndexValues map to produce a VariableValues map.
Expression.Variable	An abstract base class for variable nodes; subclasses implement getName().
ExpressionSet	ExpressionSet: represent a set of (boolean) expressions ANDed together.
Fixed	An Element that matches a single specified value.
FixedValuator	A FixedValuator is a Valuator that delivers a constant value (supplied when it is constructed).
InitialStage	The initial stage of a query, responsible for dropping the no-variables-bound seed binding domain into the remaining stages of the query pipeline.
Mapping	this class is used to record the mapping from [variable] Node's to the indexes they are bound to in a Query.
NamedGraphMap	a mapping from from names to Graphs.
NamedTripleBunches	A NamedTripleBunches maps a [graph] name to a bunch of triples associated with that name.
Pattern	A Pattern represents a matching triple; it is composed of S, P, and O Elements.
PatternStage	A PatternStage is a Stage that handles some bunch of related patterns; those patterns are encoded as Triples.
PatternStageCompiler	PatternStageCompiler serves two purposes: it contains the standard algorithm for compiling patterns-as-triples to patterns-as-Pattern(s), and it has the standard implementation of PatternCompiler in terms of ordinary Elements.
Query	The class of graph queries, plus some machinery (which should move) for implementing them.
Rewrite	Rewrite - class which does expression rewrites for Query
Rewrite.DyadicLiteral
Rewrite.DyadicLower
SimpleQueryEngine	SimpleQueryEngine
SimpleQueryHandler	A SimpleQueryHandler is a more-or-less straightforward implementation of QueryHandler suitable for use on graphs with no special query engines.
SimpleQueryPlan	SimpleQueryPlan is an implementation of QueryPlan which uses the engine defined in Query to do the work.
SimpleTreeQueryPlan	Incomplete class.
SimpleTripleSorter	A TripleSorter for "optimising" queries.
SlotValuator	A SlotValuator evaluates to a specific slot in the index values bindings.
Stage	a processing stage in the query pipeline.
Util	Util: some utility code used by graph query that doesn't seem to belong anywhere else that it can be put.
ValuatorSet	ValuatorSet - a set of Valuators, which can be added to and evaluated [only].

Exception Summary

BufferPipe.BoundedBufferPutException	Exception to throw if a put throws an exception.
BufferPipe.BoundedBufferTakeException	Exception to throw if a take throws an exception.
Query.UnboundVariableException	Exception thrown when a query variable is discovered to be unbound.

Package com.hp.hpl.jena.graph.query Description

Defines the graph-level Query classes, allowing multi-pattern query over arbitrary graphs.