org.eclipse.rdf4j.sail.helpers

Class SailConnectionWrapper

java.lang.Object

org.eclipse.rdf4j.sail.helpers.SailConnectionWrapper

All Implemented Interfaces:

AutoCloseable, FederatedServiceResolverClient, SailConnection

Direct Known Subclasses:

NotifyingSailConnectionWrapper, VerySimpleRdfsBackwardsChainingConnection

public class SailConnectionWrapper
extends Object
implements SailConnection, FederatedServiceResolverClient

An implementation of the SailConnection interface that wraps another SailConnection object and forwards any method calls to the wrapped connection.

Author:

Jeen Broekstra

Constructor Summary

Constructors

Constructor and Description
SailConnectionWrapper(SailConnection wrappedCon) Creates a new TransactionWrapper object that wraps the supplied connection.

Method Summary

Modifier and Type	Method and Description
void	addStatement(Resource subj, IRI pred, Value obj, Resource... contexts) Adds a statement to the store.
void	addStatement(UpdateContext modify, Resource subj, IRI pred, Value obj, Resource... contexts) Adds a statement to the store.
void	begin() Begins a transaction requiring SailConnection.commit() or SailConnection.rollback() to be called to close the transaction.
void	begin(IsolationLevel level) Begins a transaction with the specified IsolationLevel level, requiring SailConnection.commit() or SailConnection.rollback() to be called to close the transaction.
void	clear(Resource... contexts) Removes all statements from the specified/all contexts.
void	clearNamespaces() Removes all namespace declarations from the repository.
void	close() Closes the connection.
void	commit() Commits any updates that have been performed since the last time SailConnection.commit() or SailConnection.rollback() was called.
void	endUpdate(UpdateContext modify) Indicates that the given op will not be used in any call again.
CloseableIteration<? extends BindingSet,QueryEvaluationException>	evaluate(TupleExpr tupleExpr, Dataset dataset, BindingSet bindings, boolean includeInferred) Evaluates the supplied TupleExpr on the data contained in this Sail object, using the (optional) dataset and supplied bindings as input parameters.
Explanation	explain(Explanation.Level level, TupleExpr tupleExpr, Dataset dataset, BindingSet bindings, boolean includeInferred, int timeoutSeconds) Explain how the TupleExpr will be (or has been) executed/evaluated by returning a TupleExpr (which may or may not be the provided TupleExpr) that has gone through zero or more of the stages prior to and also including execution as specified by the provided level.
void	flush() Flushes any pending updates and notify changes to listeners as appropriate.
CloseableIteration<? extends Resource,SailException>	getContextIDs() Returns the set of all unique context identifiers that are used to store statements.
String	getNamespace(String prefix) Gets the namespace that is associated with the specified prefix, if any.
CloseableIteration<? extends Namespace,SailException>	getNamespaces() Gets the namespaces relevant to the data contained in this Sail object.
CloseableIteration<? extends Statement,SailException>	getStatements(Resource subj, IRI pred, Value obj, boolean includeInferred, Resource... contexts) Gets all statements from the specified contexts that have a specific subject, predicate and/or object.
SailConnection	getWrappedConnection() Gets the connection that is wrapped by this object.
boolean	isActive() Indicates if a transaction is currently active on the connection.
boolean	isOpen() Checks whether this SailConnection is open.
boolean	pendingRemovals() Indicates if the Sail has any statement removal operations pending (not yet flushed) for the current transaction.
void	prepare() Checks for an error state in the active transaction that would force the transaction to be rolled back.
Optional<TupleExpr>	prepareQuery(QueryLanguage ql, Query.QueryType type, String query, String baseURI) Allows the SailConnection to bypass the standard query parser and provide its own internal TupleExpr implementation.
void	removeNamespace(String prefix) Removes a namespace declaration by removing the association between a prefix and a namespace name.
void	removeStatement(UpdateContext modify, Resource subj, IRI pred, Value obj, Resource... contexts) Removes all statements matching the specified subject, predicate and object from the repository.
void	removeStatements(Resource subj, IRI pred, Value obj, Resource... contexts) Removes all statements matching the specified subject, predicate and object from the repository.
void	rollback() Rolls back the transaction, discarding any uncommitted changes that have been made in this SailConnection.
void	setFederatedServiceResolver(FederatedServiceResolver resolver) Sets the FederatedServiceResolver to use for this client.
void	setNamespace(String prefix, String name) Sets the prefix for a namespace.
void	setTransactionSettings(TransactionSetting... settings) Pass any transaction-specific settings to the SailConnection.
long	size(Resource... contexts) Returns the number of (explicit) statements in the store, or in specific contexts.
long	size(Resource context)
void	startUpdate(UpdateContext modify) Signals the start of an update operation.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.sail.SailConnection

addStatement, addStatement, getStatements, hasStatement, removeStatement, removeStatements

Constructor Detail

SailConnectionWrapper

public SailConnectionWrapper(SailConnection wrappedCon)

Creates a new TransactionWrapper object that wraps the supplied connection.

Method Detail

getWrappedConnection

public SailConnection getWrappedConnection()

Gets the connection that is wrapped by this object.

Returns:

The SailConnection object that was supplied to the constructor of this class.

setFederatedServiceResolver

public void setFederatedServiceResolver(FederatedServiceResolver resolver)

Description copied from interface: FederatedServiceResolverClient

Sets the FederatedServiceResolver to use for this client.

Specified by:

setFederatedServiceResolver in interface FederatedServiceResolverClient

Parameters:

resolver - The resolver to use.

isOpen

public boolean isOpen()
               throws SailException

Description copied from interface: SailConnection

Checks whether this SailConnection is open. A SailConnection is open from the moment it is created until it is closed.

Specified by:

isOpen in interface SailConnection

Throws:

SailException

See Also:

SailConnection.close()

close

public void close()
           throws SailException

Description copied from interface: SailConnection

Closes the connection. Any updates that haven't been committed yet will be rolled back. The connection can no longer be used once it is closed.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface SailConnection

Throws:

SailException

prepareQuery

public Optional<TupleExpr> prepareQuery(QueryLanguage ql,
                                        Query.QueryType type,
                                        String query,
                                        String baseURI)

Description copied from interface: SailConnection

Allows the SailConnection to bypass the standard query parser and provide its own internal TupleExpr implementation. By default this method returns an empty result, signaling that it will rely on the RDF4J query parser.

Specified by:

prepareQuery in interface SailConnection

Parameters:

ql - the query language.

type - indicates if the supplied query is a graph, tuple, or boolean query

query - the unparsed query string

baseURI - the provided base URI. May be null or empty.

Returns:

an optional TupleExpr that represents a sail-specific version of the query, which SailConnection.evaluate(org.eclipse.rdf4j.query.algebra.TupleExpr, org.eclipse.rdf4j.query.Dataset, org.eclipse.rdf4j.query.BindingSet, boolean) can process. Returns Optional.empty() if the Sail does not provide its own query processing.

evaluate

public CloseableIteration<? extends BindingSet,QueryEvaluationException> evaluate(TupleExpr tupleExpr,
                                                                                  Dataset dataset,
                                                                                  BindingSet bindings,
                                                                                  boolean includeInferred)
                                                                           throws SailException

Description copied from interface: SailConnection

Evaluates the supplied TupleExpr on the data contained in this Sail object, using the (optional) dataset and supplied bindings as input parameters.

Specified by:

evaluate in interface SailConnection

Parameters:

tupleExpr - The tuple expression to evaluate.

dataset - The dataset to use for evaluating the query, null to use the Sail's default dataset.

bindings - A set of input parameters for the query evaluation. The keys reference variable names that should be bound to the value they map to.

includeInferred - Indicates whether inferred triples are to be considered in the query result. If false, no inferred statements are returned; if true, inferred statements are returned if available

Returns:

The TupleQueryResult.

Throws:

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

getContextIDs

public CloseableIteration<? extends Resource,SailException> getContextIDs()
                                                                   throws SailException

Description copied from interface: SailConnection

Returns the set of all unique context identifiers that are used to store statements.

Specified by:

getContextIDs in interface SailConnection

Returns:

An iterator over the context identifiers, should not contain any duplicates.

Throws:

SailException

getStatements

public CloseableIteration<? extends Statement,SailException> getStatements(Resource subj,
                                                                           IRI pred,
                                                                           Value obj,
                                                                           boolean includeInferred,
                                                                           Resource... contexts)
                                                                    throws SailException

Description copied from interface: SailConnection

Gets all statements from the specified contexts that have a specific subject, predicate and/or object. All three parameters may be null to indicate wildcards. The includeInferred parameter can be used to control which statements are fetched: all statements or only the statements that have been added explicitly.

Specified by:

getStatements in interface SailConnection

Parameters:

subj - A Resource specifying the subject, or null for a wildcard.

pred - A URI specifying the predicate, or null for a wildcard.

obj - A Value specifying the object, or null for a wildcard.

includeInferred - if false, no inferred statements are returned; if true, inferred statements are returned if available

contexts - The context(s) to get the data from. Note that this parameter is a vararg and as such is optional. If no contexts are specified the method operates on the entire repository. A null value can be used to match context-less statements.

Returns:

The statements matching the specified pattern.

Throws:

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

size

public long size(Resource... contexts)
          throws SailException

Description copied from interface: SailConnection

Returns the number of (explicit) statements in the store, or in specific contexts.

Specified by:

size in interface SailConnection

Parameters:

contexts - The context(s) to determine the size of. Note that this parameter is a vararg and as such is optional. If no contexts are specified the method operates on the entire repository. A null value can be used to match context-less statements.

Returns:

The number of explicit statements in this store, or in the specified context(s).

Throws:

SailException

size

public long size(Resource context)
          throws SailException

Throws:

SailException

commit

public void commit()
            throws SailException

Description copied from interface: SailConnection

Commits any updates that have been performed since the last time SailConnection.commit() or SailConnection.rollback() was called.

Specified by:

commit in interface SailConnection

Throws:

UnknownSailTransactionStateException - If the transaction state can not be determined (this can happen for instance when communication between client and server fails or times-out). It does not indicate a problem with the integrity of the store.

SailException - If the SailConnection could not be committed.

rollback

public void rollback()
              throws SailException

Description copied from interface: SailConnection

Rolls back the transaction, discarding any uncommitted changes that have been made in this SailConnection.

Specified by:

rollback in interface SailConnection

Throws:

UnknownSailTransactionStateException - If the transaction state can not be determined (this can happen for instance when communication between client and server fails or times-out). It does not indicate a problem with the integrity of the store.

SailException - If the SailConnection could not be rolled back.

addStatement

public void addStatement(Resource subj,
                         IRI pred,
                         Value obj,
                         Resource... contexts)
                  throws SailException

Description copied from interface: SailConnection

Adds a statement to the store.

Specified by:

addStatement in interface SailConnection

Parameters:

subj - The subject of the statement to add.

pred - The predicate of the statement to add.

obj - The object of the statement to add.

contexts - The context(s) to add the statement to. Note that this parameter is a vararg and as such is optional. If no contexts are specified, a context-less statement will be added.

Throws:

SailException - If the statement could not be added, for example because no transaction is active.

removeStatements

public void removeStatements(Resource subj,
                             IRI pred,
                             Value obj,
                             Resource... contexts)
                      throws SailException

Description copied from interface: SailConnection

Removes all statements matching the specified subject, predicate and object from the repository. All three parameters may be null to indicate wildcards.

Specified by:

removeStatements in interface SailConnection

Parameters:

subj - The subject of the statement that should be removed, or null to indicate a wildcard.

pred - The predicate of the statement that should be removed, or null to indicate a wildcard.

obj - The object of the statement that should be removed , or null to indicate a wildcard. *

contexts - The context(s) from which to remove the statement. Note that this parameter is a vararg and as such is optional. If no contexts are specified the method operates on the entire repository. A null value can be used to match context-less statements.

Throws:

SailException - If the statement could not be removed, for example because no transaction is active.

startUpdate

public void startUpdate(UpdateContext modify)
                 throws SailException

Description copied from interface: SailConnection

Signals the start of an update operation. The given op maybe passed to subsequent SailConnection.addStatement(UpdateContext, Resource, IRI, Value, Resource...) or SailConnection.removeStatement(UpdateContext, Resource, IRI, Value, Resource...) calls before SailConnection.endUpdate(UpdateContext) is called.

Specified by:

startUpdate in interface SailConnection

Throws:

SailException

addStatement

public void addStatement(UpdateContext modify,
                         Resource subj,
                         IRI pred,
                         Value obj,
                         Resource... contexts)
                  throws SailException

Description copied from interface: SailConnection

Adds a statement to the store. Called when adding statements through a UpdateExpr operation.

Specified by:

addStatement in interface SailConnection

Parameters:

modify - operation properties of the UpdateExpr operation producing these statements.

subj - The subject of the statement to add.

pred - The predicate of the statement to add.

obj - The object of the statement to add.

contexts - The context(s) to add the statement to. Note that this parameter is a vararg and as such is optional. If no contexts are specified, a context-less statement will be added.

Throws:

SailException - If the statement could not be added, for example because no transaction is active.

removeStatement

public void removeStatement(UpdateContext modify,
                            Resource subj,
                            IRI pred,
                            Value obj,
                            Resource... contexts)
                     throws SailException

Description copied from interface: SailConnection

Removes all statements matching the specified subject, predicate and object from the repository. All three parameters may be null to indicate wildcards. Called when removing statements through a UpdateExpr operation.

Specified by:

removeStatement in interface SailConnection

Parameters:

modify - operation properties of the UpdateExpr operation removing these statements.

subj - The subject of the statement that should be removed.

pred - The predicate of the statement that should be removed.

obj - The object of the statement that should be removed.

contexts - The context(s) from which to remove the statement. Note that this parameter is a vararg and as such is optional. If no contexts are specified the method operates on the entire repository. A null value can be used to match context-less statements.

Throws:

SailException - If the statement could not be removed, for example because no transaction is active.

endUpdate

public void endUpdate(UpdateContext modify)
               throws SailException

Description copied from interface: SailConnection

Indicates that the given op will not be used in any call again. Implementations should use this to flush of any temporary operation states that may have occurred.

Specified by:

endUpdate in interface SailConnection

Throws:

SailException

clear

public void clear(Resource... contexts)
           throws SailException

Description copied from interface: SailConnection

Removes all statements from the specified/all contexts. If no contexts are specified the method operates on the entire repository.

Specified by:

clear in interface SailConnection

Parameters:

contexts - The context(s) from which to remove the statements. Note that this parameter is a vararg and as such is optional. If no contexts are specified the method operates on the entire repository. A null value can be used to match context-less statements.

Throws:

SailException - If the statements could not be removed.

getNamespaces

public CloseableIteration<? extends Namespace,SailException> getNamespaces()
                                                                    throws SailException

Description copied from interface: SailConnection

Gets the namespaces relevant to the data contained in this Sail object.

Specified by:

getNamespaces in interface SailConnection

Returns:

An iterator over the relevant namespaces, should not contain any duplicates.

Throws:

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

getNamespace

public String getNamespace(String prefix)
                    throws SailException

Description copied from interface: SailConnection

Gets the namespace that is associated with the specified prefix, if any.

Specified by:

getNamespace in interface SailConnection

Parameters:

prefix - A namespace prefix, or an empty string in case of the default namespace.

Returns:

The namespace name that is associated with the specified prefix, or null if there is no such namespace.

Throws:

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

setNamespace

public void setNamespace(String prefix,
                         String name)
                  throws SailException

Description copied from interface: SailConnection

Sets the prefix for a namespace.

Specified by:

setNamespace in interface SailConnection

Parameters:

prefix - The new prefix, or an empty string in case of the default namespace.

name - The namespace name that the prefix maps to.

Throws:

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

removeNamespace

public void removeNamespace(String prefix)
                     throws SailException

Description copied from interface: SailConnection

Removes a namespace declaration by removing the association between a prefix and a namespace name.

Specified by:

removeNamespace in interface SailConnection

Parameters:

prefix - The namespace prefix, or an empty string in case of the default namespace.

Throws:

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

clearNamespaces

public void clearNamespaces()
                     throws SailException

Description copied from interface: SailConnection

Removes all namespace declarations from the repository.

Specified by:

clearNamespaces in interface SailConnection

Throws:

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

pendingRemovals

public boolean pendingRemovals()

Description copied from interface: SailConnection

Indicates if the Sail has any statement removal operations pending (not yet flushed) for the current transaction.

Specified by:

pendingRemovals in interface SailConnection

Returns:

true if any statement removal operations have not yet been flushed, false otherwise.

See Also:

SailConnection.flush()

explain

public Explanation explain(Explanation.Level level,
                           TupleExpr tupleExpr,
                           Dataset dataset,
                           BindingSet bindings,
                           boolean includeInferred,
                           int timeoutSeconds)

Description copied from interface: SailConnection

Explain how the TupleExpr will be (or has been) executed/evaluated by returning a TupleExpr (which may or may not be the provided TupleExpr) that has gone through zero or more of the stages prior to and also including execution as specified by the provided level.

This method is used by the Query interface.

WARNING: This method is experimental and is subject to change or removal without warning. There is currently only partial support for this method in RDF4J and and UnsupportedOperationException where support is lacking.

Specified by:

explain in interface SailConnection

Parameters:

level - the explanation level, eg. OPTIMIZED

tupleExpr - The tuple expression to evaluate. Mutable.

dataset - The dataset to use for evaluating the query, null to use the Sail's default dataset.

bindings - A set of input parameters for the query evaluation. The keys reference variable names that should be bound to the value they map to.

includeInferred - Indicates whether inferred triples are to be considered in the query result. If false, no inferred statements are returned; if true, inferred statements are returned if available

timeoutSeconds - for explanations that require execution a timeout can be provided in seconds

Returns:

The resulting tuple expression after being run through the specified level

begin

public void begin()
           throws SailException

Description copied from interface: SailConnection

Begins a transaction requiring SailConnection.commit() or SailConnection.rollback() to be called to close the transaction. The transaction will use the default IsolationLevel level for the SAIL, as returned by Sail.getDefaultIsolationLevel().

Specified by:

begin in interface SailConnection

Throws:

SailException - If the connection could not start a transaction or if a transaction is already active on this connection.

begin

public void begin(IsolationLevel level)
           throws SailException

Description copied from interface: SailConnection

Begins a transaction with the specified IsolationLevel level, requiring SailConnection.commit() or SailConnection.rollback() to be called to close the transaction.

Specified by:

begin in interface SailConnection

Parameters:

level - the transaction isolation level on which this transaction operates.

Throws:

UnknownSailTransactionStateException - If the IsolationLevel is not supported by this implementation

SailException - If the connection could not start a transaction, if the supplied transaction isolation level is not supported, or if a transaction is already active on this connection.

setTransactionSettings

public void setTransactionSettings(TransactionSetting... settings)

Description copied from interface: SailConnection

Pass any transaction-specific settings to the SailConnection. This method needs to be called before the transaction is started .

Sail implementations can override this method to receive the transaction settings (to inspect and/or pass them along to any wrapped sail objects). Remember to call super.setTransactionSettings(settings) if you override this method.

Specified by:

setTransactionSettings in interface SailConnection

Parameters:

settings - the transaction settings on which the next transaction operates. It may or may not contain the isolation level.

flush

public void flush()
           throws SailException

Description copied from interface: SailConnection

Flushes any pending updates and notify changes to listeners as appropriate. This is an optional call; calling or not calling this method should have no effect on the outcome of other calls. This method exists to give the caller more control over the efficiency when calling SailConnection.prepare(). This method may be called multiple times within the same transaction.

Specified by:

flush in interface SailConnection

Throws:

SailException - If the updates could not be processed, for example because no transaction is active.

prepare

public void prepare()
             throws SailException

Description copied from interface: SailConnection

Checks for an error state in the active transaction that would force the transaction to be rolled back. This is an optional call; calling or not calling this method should have no effect on the outcome of SailConnection.commit() or SailConnection.rollback(). A call to this method must be followed by (in the same thread) with a call to SailConnection.prepare() , SailConnection.commit(), SailConnection.rollback(), or SailConnection.close() . This method may be called multiple times within the same transaction by the same thread. If this method returns normally, the caller can reasonably expect that a subsequent call to SailConnection.commit() will also return normally. If this method returns with an exception the caller should treat the exception as if it came from a call to SailConnection.commit().

Specified by:

prepare in interface SailConnection

Throws:

UnknownSailTransactionStateException - If the transaction state can not be determined (this can happen for instance when communication between client and server fails or times-out). It does not indicate a problem with the integrity of the store.

SailException - If there is an active transaction and it cannot be committed.

isActive

public boolean isActive()
                 throws UnknownSailTransactionStateException

Description copied from interface: SailConnection

Indicates if a transaction is currently active on the connection. A transaction is active if SailConnection.begin() has been called, and becomes inactive after SailConnection.commit() or SailConnection.rollback() has been called.

Specified by:

isActive in interface SailConnection

Returns:

true iff a transaction is active, false iff no transaction is active.

Throws:

UnknownSailTransactionStateException - if the transaction state can not be determined (this can happen for instance when communication between client and server fails or times out).