Package com.stardog.stark

Class Graphs

java.lang.Object

com.stardog.stark.Graphs

public final class Graphs
extends Object

Utilities for working with collections of RDF statements.

Since:

1.0

Version:

1.0

Author:

Michael Grove

Constructor Summary

Constructors

Constructor	Description
Graphs()

Method Summary

Modifier and Type	Method	Description
static Set<Statement>	applyContext(Collection<Statement> theStatements, Resource theContext)	Create a copy of the statements, modifying them, to apply the given context to each.
static List<Value>	asList(Collection<Statement> theGraph, Resource theRes)	Return the contents of the given list by following the `rdf:first`/`rdf:rest` structure of the list
static Set<Resource>	contexts(Collection<Statement> theStatements)
static boolean	isList(Collection<Statement> theGraph, Resource theRes)	Returns whether or not the given resource is a `rdf:List`
static boolean	isomorphic(Iterable<? extends Statement> model1, Iterable<? extends Statement> model2)	Compares two RDF models, and returns true if they consist of isomorphic graphs and the isomorphic graph identifiers map 1:1 to each other.
static Stream<Statement>	matching(Iterable<Statement> theStmts, StatementPattern thePattern)	Return all the statements that match the pattern.
static Set<Statement>	named(Iterable<Statement> theStatements, Resource theContext)	Apply the given context to all of the statements, including Statement values in the subject position.
static Optional<Value>	object(Iterable<Statement> theStatements, Resource theSubj, IRI thePred)	Return the object for the given SP.
static Set<Value>	objects(Collection<Statement> theStatements)
static Set<IRI>	predicates(Collection<Statement> theStatements)
static Set<Resource>	subjects(Collection<Statement> theStatements)
static Stream<Resource>	subjectsOfType(Iterable<Statement> theStatements, IRI theClass)
static Set<Statement>	toList(List<Resource> theResources)	Return the contents of the list serialized as an RDF list

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Graphs

public Graphs()

Method Details

subjects

@Nonnull
public static Set<Resource> subjects(@Nonnull
 Collection<Statement> theStatements)

predicates

@Nonnull
public static Set<IRI> predicates(@Nonnull
 Collection<Statement> theStatements)

objects

@Nonnull
public static Set<Value> objects(@Nonnull
 Collection<Statement> theStatements)

contexts

@Nonnull
public static Set<Resource> contexts(@Nonnull
 Collection<Statement> theStatements)

applyContext

@Nonnull
public static Set<Statement> applyContext(@Nonnull
 Collection<Statement> theStatements,
 @Nonnull
 Resource theContext)

Create a copy of the statements, modifying them, to apply the given context to each.

Parameters:

theStatements - the statements

theContext - the new context

Returns:

the new statements

matching

@Nonnull
public static Stream<Statement> matching(@Nonnull
 Iterable<Statement> theStmts,
 @Nonnull
 StatementPattern thePattern)

Return all the statements that match the pattern.

Parameters:

theStmts - the statements

thePattern - the pattern to match

Returns:

the matching statements

object

@Nonnull
public static Optional<Value> object(@Nonnull
 Iterable<Statement> theStatements,
 @Nonnull
 Resource theSubj,
 @Nonnull
 IRI thePred)

Return the object for the given SP. If the SP combination has more than one object associated with it, only the first one will be returned.

Parameters:

theStatements - the statements

theSubj - the subject

thePred - the predicate

Returns:

the object for the given SP

named

@Nonnull
public static Set<Statement> named(@Nonnull
 Iterable<Statement> theStatements,
 @Nonnull
 Resource theContext)

Apply the given context to all of the statements, including Statement values in the subject position.

Parameters:

theStatements - the graph of statements

theContext - the context to apply

Returns:

A *new* set of statements all of which are in the given context

isList

public static boolean isList(@Nonnull
 Collection<Statement> theGraph,
 @Nonnull
 Resource theRes)

Returns whether or not the given resource is a `rdf:List`

Parameters:

theGraph - the graph

theRes - the resource to check

Returns:

`true` if its a list, `false` otherwise

asList

@Nonnull
public static List<Value> asList(@Nonnull
 Collection<Statement> theGraph,
 @Nonnull
 Resource theRes)

Return the contents of the given list by following the `rdf:first`/`rdf:rest` structure of the list

Parameters:

theGraph - the graph

theRes - the resource which is the head of the list

Returns:

the contents of the list.

toList

@Nonnull
public static Set<Statement> toList(@Nonnull
 List<Resource> theResources)

Return the contents of the list serialized as an RDF list

Parameters:

theResources - the list

Returns:

the list as RDF

isomorphic

public static boolean isomorphic(@Nonnull
 Iterable<? extends Statement> model1,
 @Nonnull
 Iterable<? extends Statement> model2)

Compares two RDF models, and returns true if they consist of isomorphic graphs and the isomorphic graph identifiers map 1:1 to each other. RDF graphs are isomorphic graphs if statements from one graphs can be mapped 1:1 on to statements in the other graphs. In this mapping, blank nodes are not considered mapped when having an identical internal id, but are mapped from one graph to the other by looking at the statements in which the blank nodes occur.

A Model can consist of more than one graph (denoted by context identifiers). Two models are considered isomorphic if for each of the graphs in one model, an isomorphic graph exists in the other model, and the context identifiers of these graphs are either identical or (in the case of blank nodes) map 1:1 on each other.

See Also:

• RDF Concepts & Abstract Syntax, section 3.6 (Graph Comparison)

subjectsOfType

public static Stream<Resource> subjectsOfType(Iterable<Statement> theStatements,
 IRI theClass)