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.
QueryNodeFactory
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

Applyer	An Applyer object will run the StageElement next over all the extensions of the Domain d which are derived from applying the Matcher m to some internal supply of triples.
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).
GraphQuery	The class of graph queries, plus some machinery (which should move) for implementing them.
GuardArranger	A GuardArranger is initialised with a set of triple patterns, and can then turn a set of constraints (plus a map giving the location of variables) into an array of guards, where the i'th element of the array is the set of constraints that can be evaluated as soon as the i'th triple-pattern has been processed.
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.
Matcher	A Matcher knows how to match itself against a concrete triple (the triple to be matched) and a domain (of bindings to check and extend).
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.
PatternStageBase	PatternStageBase contains the features that are common to the traditional PatternStage engine and the Faster engine.
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.
QueryNode	A QueryNode is a wrapped node that has been processed against some variable-binding map to discover (a) what kind of node it is and (b) what index in the binding map it has.
QueryNode.Any
QueryNode.Bind
QueryNode.Bound
QueryNode.Fixed
QueryNode.JustBound
QueryNodeFactoryBase	A base-level implementation of the QueryNodeFactory that uses the QueryNode/QueryTriple classes directly.
QueryTriple	A QueryTriple is a composite of three QueryNodes derived from a single source triple.
QueryTriple.SimpleApplyer
Rewrite	Rewrite - class which does expression rewrites for Query
Rewrite.DyadicLiteral
SimpleQueryEngine	SimpleQueryEngine
SimpleQueryEngine.Cons
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.
StageElement	Class used internally by PatternStage to express the notion of "the runnable next component in this stage".
StageElement.FindTriples	A FindTriples runs match-and-next over all the triples returned by its finder.
StageElement.PutBindings	A PutBindings is created with a domain sink and, whenever it is run, puts a copy of the current domain down the sink.
StageElement.RunValuatorSet	A RunValuatorSet is created with a ValuatorSet and a next StageElement; whenever it is run, it evaluates the ValuatorSet and only if that answers true does it run the next StageElement.
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.
GraphQuery.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.