org.eclipse.rdf4j.sail

Interface Sail

All Known Subinterfaces:

NotifyingSail, StackableSail

All Known Implementing Classes:

AbstractNotifyingSail, AbstractSail, NotifyingSailBase, NotifyingSailWrapper, SailBase, SailWrapper

public interface Sail

Sail (Storage And Inference Layer) is an interface for RDF storage. RDF Sails can store RDF statements and evaluate queries over them. Statements can be stored in named contexts or in the null context. Contexts can be used to group sets of statements that logically belong together, for example because they come from the same source. Both URIs and blank nodes can be used as context identifiers.

Author:

Arjohn Kampman

Method Summary

Modifier and Type	Method and Description
SailConnection	getConnection() Opens a connection on the Sail which can be used to query and update data.
File	getDataDir() Gets the Sail's data directory.
IsolationLevel	getDefaultIsolationLevel() Retrieves the default IsolationLevel level on which transactions in this Sail operate.
List<IsolationLevel>	getSupportedIsolationLevels() Retrieve the IsolationLevels supported by this SAIL, ordered by increasing complexity.
ValueFactory	getValueFactory() Gets a ValueFactory object that can be used to create IRI-, blank node-, literal- and statement objects.
void	initialize() Initializes the Sail.
boolean	isWritable() Checks whether this Sail object is writable, i.e.
void	setDataDir(File dataDir) Sets the data directory for the Sail.
void	shutDown() Shuts down the Sail, giving it the opportunity to synchronize any stale data.

Method Detail

setDataDir

void setDataDir(File dataDir)

Sets the data directory for the Sail. The Sail can use this directory for storage of data, parameters, etc. This directory must be set before the Sail is initialized.

Throws:

IllegalStateException - If this method is called when the Sail has already been initialized.

getDataDir

File getDataDir()

Gets the Sail's data directory.

See Also:

setDataDir(File)

initialize

void initialize()
         throws SailException

Initializes the Sail. Care should be taken that required initialization parameters have been set before this method is called. Please consult the specific Sail implementation for information about the relevant parameters.

Throws:

SailException - If the Sail could not be initialized.

IllegalStateException - If the Sail has already been initialized.

shutDown

void shutDown()
       throws SailException

Shuts down the Sail, giving it the opportunity to synchronize any stale data. Care should be taken that all initialized Sails are being shut down before an application exits to avoid potential loss of data. Once shut down, a Sail can no longer be used until it is re-initialized.

Throws:

SailException - If the Sail object encountered an error or unexpected situation internally.

isWritable

boolean isWritable()
            throws SailException

Checks whether this Sail object is writable, i.e. if the data contained in this Sail object can be changed.

Throws:

SailException

getConnection

SailConnection getConnection()
                      throws SailException

Opens a connection on the Sail which can be used to query and update data. Depending on how the implementation handles concurrent access, a call to this method might block when there is another open connection on this Sail.

Throws:

SailException - If no transaction could be started, for example because the Sail is not writable.

IllegalStateException - If the Sail has not been initialized or has been shut down.

getValueFactory

ValueFactory getValueFactory()

Gets a ValueFactory object that can be used to create IRI-, blank node-, literal- and statement objects.

Returns:

a ValueFactory object for this Sail object.

getSupportedIsolationLevels

List<IsolationLevel> getSupportedIsolationLevels()

Retrieve the IsolationLevels supported by this SAIL, ordered by increasing complexity.

Returns:

a non-empty List of supported Isolation Levels, in order of increasing complexity. Every SAIL supports at least one IsolationLevel.

getDefaultIsolationLevel

IsolationLevel getDefaultIsolationLevel()

Retrieves the default IsolationLevel level on which transactions in this Sail operate.

Returns:

the IsolationLevel that will be used with SailConnection.begin(), for SAIL connections returned by getConnection().