Package com.complexible.common.rdf

Interface StatementSource

All Superinterfaces:

java.lang.AutoCloseable, java.io.Closeable

All Known Subinterfaces:

ContextCopyStatementSource, RDFFileSupplier, RDFStreamSupplier

All Known Implementing Classes:

ContextFallbackStatementSource, ContextOverrideStatementSource, DelegatingStatementSource, StatementSources.RDFStreamStatementSource

public interface StatementSource
extends java.io.Closeable

Interface which represents a source of a set of RDF statements. The actual source of the statements can be an in-memory graph, a file on disk, a socket or network connection, etc.

Care should be taken to sure that all StatementSource objects are closed to free up any resources they are holding.

Since:

0.3.1

Version:

6.0

Author:

Michael Grove, Fernando Hernandez

Field Summary

Fields

Modifier and Type	Field	Description
static long	NO_ESTIMATE

Method Summary

Modifier and Type	Method	Description
default boolean	containsVirtual()	Returns true if the statement source represents, at least partially, the contents of a Virtual Graph
default long	estimatedCount()	Returns the estimated count of statements in this source or NO_ESTIMATE if the estimate is not known.
Resource	getContext()	Return the context these statements belong to.
default boolean	inMemory()	Returns true if all statements are held in memory
StatementIterator	statements()	Return an iterator over the statements contained by this source.
java.util.List<RDFStream>	streams()	Converts the statement source into one or more streams.

Methods inherited from interface java.io.Closeable

close

Field Detail

NO_ESTIMATE

static final long NO_ESTIMATE

See Also:

Constant Field Values

Method Detail

statements

StatementIterator statements()

Return an iterator over the statements contained by this source.

Returns:

an iteration over the statements.

Implementation Requirements:

Implementations must ensure that this method can be called more than once and the resulting iterators can be used independently.

Implementation Notes:

Closing the iterator, when applicable, does not clean up the source, only the iterator. You must close the source separately.

getContext

Resource getContext()

Return the context these statements belong to. When non-null, this should override the context specified on the statements themselves.

Returns:

the context of all the statements from this source, or `null` if there is no context (for all of them) or they each have their own context specified.

streams

java.util.List<RDFStream> streams()

Converts the statement source into one or more streams.

estimatedCount

default long estimatedCount()

Returns the estimated count of statements in this source or NO_ESTIMATE if the estimate is not known.

containsVirtual

default boolean containsVirtual()

Returns true if the statement source represents, at least partially, the contents of a Virtual Graph

inMemory

default boolean inMemory()

Returns true if all statements are held in memory

Returns:

true if all statements are held in memory