development
This commit is contained in:
stellamit
parent
423ec922d8
commit
0219f927ba
4 changed files with 561 additions and 10 deletions
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@ -15,7 +15,7 @@ public interface ModelChange {
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ADD, REMOVE
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}
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abstract InputStream getSerializedModel();
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public InputStream getSerializedModel();
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public void setSerializedModel(InputStream serializedModel);
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@ -3,6 +3,7 @@
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package edu.cornell.mannlib.vitro.webapp.rdfservice;
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import java.io.InputStream;
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import java.io.OutputStream;
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import java.util.List;
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/*
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@ -22,13 +23,16 @@ public interface RDFService {
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/**
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* Perform a series of additions to and or removals from specified graphs
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* in the RDF store. For each change preConditionSparql will be executed
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* before the update is made and if it returns a non-empty result, no updates
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* will be made. The same preConditionSparql is used for each change/graph pair.
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* in the RDF store. preConditionSparql will be executed against the
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* union of all the graphs in the knowledge base before any updates are made.
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* If the precondition query returns a non-empty result, no updates
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* will be made.
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*
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* @param ChangeSet - a set of changes to be performed on the RDF store.
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* @param ChangeSet - a set of changes to be performed on the RDF store.
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*
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* @return boolean - indicates whether the precondition was satisfied
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*/
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public void changeSetUpdate(ChangeSet changeSet) throws RDFServiceException;
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public boolean changeSetUpdate(ChangeSet changeSet) throws RDFServiceException;
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/**
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* If the given individual already exists in the default graph, throws an
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@ -52,16 +56,49 @@ public interface RDFService {
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public void newIndividual(String individualURI, String individualTypeURI, String graphURI) throws RDFServiceException;
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/**
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* Performs a SPARQL query against the knowledge base. The query may have
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* Performs a SPARQL construct query against the knowledge base. The query may have
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* an embedded graph identifier.
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*
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* @param String query - the SPARQL query to be executed against the RDF store
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* @param RDFService.ModelSerializationFormat resultFormat - type of serialization for RDF result of the SPARQL query
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* @param OutputStream outputStream - the result of the query
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*
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*/
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public InputStream sparqlConstructQuery(String query, RDFService.ModelSerializationFormat resultFormat) throws RDFServiceException;
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/**
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* Performs a SPARQL describe query against the knowledge base. The query may have
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* an embedded graph identifier.
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*
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* @param String query - the SPARQL query to be executed against the RDF store
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* @param RDFService.SPARQLQueryType queryType - the type of SPARQL query (SELECT, CONSTRUCT, DESCRIBE, ASK)
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* @param RDFService.ModelSerializationFormat resultFormat - type of serialization for RDF result of the SPARQL query
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*
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* @return InputStream - the result of the SPARQL query
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* @return InputStream - the result of the query
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*
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*/
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public InputStream sparqlConstructQuery(String query, RDFService.SPARQLQueryType queryType, RDFService.ModelSerializationFormat resultFormat) throws RDFServiceException;
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public InputStream sparqlDescribeQuery(String query, RDFService.ModelSerializationFormat resultFormat) throws RDFServiceException;
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/**
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* Performs a SPARQL select query against the knowledge base. The query may have
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* an embedded graph identifier.
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*
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* @param String query - the SPARQL query to be executed against the RDF store
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*
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* @return InputStream - the result of the query
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*
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*/
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public InputStream sparqlSelectQuery(String query) throws RDFServiceException;
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/**
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* Performs a SPARQL ASK query against the knowledge base. The query may have
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* an embedded graph identifier.
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*
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* @param String query - the SPARQL query to be executed against the RDF store
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*
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* @return boolean - the result of the SPARQL query
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*/
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public boolean sparqlAskQuery(String query) throws RDFServiceException;
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/**
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* Get a list of all the graph URIs in the RDF store.
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@ -5,5 +5,9 @@ public class RDFServiceException extends Exception {
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public RDFServiceException() {
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super();
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}
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public RDFServiceException(String message) {
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super(message);
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}
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}
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@ -0,0 +1,510 @@
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/* $This file is distributed under the terms of the license in /doc/license.txt$ */
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package edu.cornell.mannlib.vitro.webapp.rdfservice.impl;
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import java.io.ByteArrayInputStream;
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import java.io.ByteArrayOutputStream;
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import java.io.InputStream;
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import java.util.Iterator;
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import java.util.List;
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import org.apache.commons.logging.Log;
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import org.apache.commons.logging.LogFactory;
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import org.openrdf.query.MalformedQueryException;
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import org.openrdf.query.QueryLanguage;
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import org.openrdf.query.Update;
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import org.openrdf.query.UpdateExecutionException;
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import org.openrdf.repository.Repository;
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import org.openrdf.repository.RepositoryConnection;
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import org.openrdf.repository.RepositoryException;
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import org.openrdf.repository.http.HTTPRepository;
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import com.hp.hpl.jena.graph.Node;
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import com.hp.hpl.jena.graph.Triple;
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import com.hp.hpl.jena.query.Query;
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import com.hp.hpl.jena.query.QueryExecution;
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import com.hp.hpl.jena.query.QueryExecutionFactory;
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import com.hp.hpl.jena.query.QueryFactory;
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import com.hp.hpl.jena.query.ResultSet;
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import com.hp.hpl.jena.query.ResultSetFormatter;
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import com.hp.hpl.jena.rdf.model.Model;
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import com.hp.hpl.jena.rdf.model.ModelFactory;
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import com.hp.hpl.jena.rdf.model.Statement;
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import com.hp.hpl.jena.rdf.model.StmtIterator;
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import edu.cornell.mannlib.vitro.webapp.rdfservice.ChangeListener;
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import edu.cornell.mannlib.vitro.webapp.rdfservice.ChangeSet;
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import edu.cornell.mannlib.vitro.webapp.rdfservice.ModelChange;
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import edu.cornell.mannlib.vitro.webapp.rdfservice.RDFService;
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import edu.cornell.mannlib.vitro.webapp.rdfservice.RDFServiceException;
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/*
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* API to write, read, and update Vitro's RDF store, with support
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* to allow listening, logging and auditing.
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*/
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public class RDFServiceImpl implements RDFService {
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private static final Log log = LogFactory.getLog(RDFServiceImpl.class);
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private String endpointURI;
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private Repository repository;
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/**
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* Returns an RDFService for a remote repository
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* @param endpointURI
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*/
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public RDFServiceImpl(String endpointURI) {
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this.endpointURI = endpointURI;
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this.repository = new HTTPRepository(endpointURI);
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}
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/**
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* Perform a series of additions to and or removals from specified graphs
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* in the RDF store. preConditionSparql will be executed against the
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* union of all the graphs in the knowledge base before any updates are made.
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* If the precondition query returns a non-empty result, no updates
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* will be made.
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*
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* @param ChangeSet - a set of changes to be performed on the RDF store.
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*
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* @return boolean - indicates whether the precondition was satisfied
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*/
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@Override
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public boolean changeSetUpdate(ChangeSet changeSet) throws RDFServiceException {
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if (!isPreconditionSatisfied(changeSet.getPreconditionQuery(), changeSet.getPreconditionQueryType())) {
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return false;
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}
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Iterator<ModelChange> csIt = changeSet.getModelChanges().iterator();
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while (csIt.hasNext()) {
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ModelChange modelChange = csIt.next();
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if (modelChange.getOperation() == ModelChange.Operation.ADD) {
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performAdd(modelChange);
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} else if (modelChange.getOperation() == ModelChange.Operation.REMOVE) {
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performRemove(modelChange);
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} else {
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log.error("unrecognized operation type");
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}
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}
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return true;
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}
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/**
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* If the given individual already exists in the default graph, throws an
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* RDFServiceException, otherwise adds one type assertion to the default
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* graph.
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*
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* @param String individualURI - URI of the individual to be added
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* @param String individualTypeURI - URI of the type for the individual
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*/
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@Override
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public void newIndividual(String individualURI,
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String individualTypeURI) throws RDFServiceException {
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}
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/**
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* If the given individual already exists in the given graph, throws an
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* RDFServiceException, otherwise adds one type assertion to the given
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* graph.
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*
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* @param String individualURI - URI of the individual to be added
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* @param String individualTypeURI - URI of the type for the individual
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* @param String graphURI - URI of the graph to which to add the individual
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*/
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@Override
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public void newIndividual(String individualURI,
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String individualTypeURI,
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String graphURI) throws RDFServiceException {
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}
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/**
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* Performs a SPARQL construct query against the knowledge base. The query may have
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* an embedded graph identifier.
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*
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* @param String query - the SPARQL query to be executed against the RDF store
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* @param RDFService.ModelSerializationFormat resultFormat - type of serialization for RDF result of the SPARQL query
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* @param OutputStream outputStream - the result of the query
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*
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*/
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@Override
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public InputStream sparqlConstructQuery(String queryStr,
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RDFServiceImpl.ModelSerializationFormat resultFormat) throws RDFServiceException {
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Model model = ModelFactory.createDefaultModel();
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Query query = QueryFactory.create(queryStr);
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QueryExecution qe = QueryExecutionFactory.sparqlService(endpointURI, query);
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try {
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qe.execConstruct(model);
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} finally {
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qe.close();
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}
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ByteArrayOutputStream serializedModel = new ByteArrayOutputStream();
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model.write(serializedModel,getSerializationFormatString(resultFormat));
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InputStream result = new ByteArrayInputStream(serializedModel.toByteArray());
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return result;
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}
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/**
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* Performs a SPARQL describe query against the knowledge base. The query may have
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* an embedded graph identifier.
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*
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* @param String query - the SPARQL query to be executed against the RDF store
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* @param RDFService.ModelSerializationFormat resultFormat - type of serialization for RDF result of the SPARQL query
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*
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* @return InputStream - the result of the query
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*
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*/
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@Override
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public InputStream sparqlDescribeQuery(String queryStr,
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RDFServiceImpl.ModelSerializationFormat resultFormat) throws RDFServiceException {
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Model model = ModelFactory.createDefaultModel();
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Query query = QueryFactory.create(queryStr);
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QueryExecution qe = QueryExecutionFactory.sparqlService(endpointURI, query);
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try {
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qe.execDescribe(model);
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} finally {
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qe.close();
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}
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ByteArrayOutputStream serializedModel = new ByteArrayOutputStream();
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model.write(serializedModel,getSerializationFormatString(resultFormat));
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InputStream result = new ByteArrayInputStream(serializedModel.toByteArray());
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return result;
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}
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/**
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* Performs a SPARQL select query against the knowledge base. The query may have
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* an embedded graph identifier.
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*
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* @param String query - the SPARQL query to be executed against the RDF store
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*
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* @return InputStream - the result of the query
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*
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*/
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@Override
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public InputStream sparqlSelectQuery(String queryStr) throws RDFServiceException {
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Query query = QueryFactory.create(queryStr);
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QueryExecution qe = QueryExecutionFactory.sparqlService(endpointURI, query);
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try {
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ResultSet resultSet = qe.execSelect();
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ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
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ResultSetFormatter.out(outputStream,resultSet);
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InputStream result = new ByteArrayInputStream(outputStream.toByteArray());
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return result;
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} finally {
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qe.close();
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}
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}
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/**
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* Performs a SPARQL ASK query against the knowledge base. The query may have
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* an embedded graph identifier.
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*
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* @param String query - the SPARQL query to be executed against the RDF store
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*
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* @return boolean - the result of the SPARQL query
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*/
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@Override
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public boolean sparqlAskQuery(String queryStr) throws RDFServiceException {
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Query query = QueryFactory.create(queryStr);
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QueryExecution qe = QueryExecutionFactory.sparqlService(endpointURI, query);
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try {
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return qe.execAsk();
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} finally {
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qe.close();
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}
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}
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/**
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* Get a list of all the graph URIs in the RDF store.
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*
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* @return List<String> - list of all the graph URIs in the RDF store
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*/
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@Override
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public List<String> getGraphURIs() throws RDFServiceException {
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List<String> list = null;
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return list;
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}
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/**
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* TODO - what is the definition of this method?
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* @return
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*/
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@Override
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public void getGraphMetadata() throws RDFServiceException {
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}
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/**
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* Get the URI of the default write graph
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*
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* @return String URI of default write graph
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*/
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@Override
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public String getDefaultWriteGraphURI() throws RDFServiceException {
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String graphURI = null;
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return graphURI;
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}
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/**
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* Get the URI of the default read graph
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*
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* @return String URI of default read graph
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*/
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@Override
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public String getDefaultReadGraphURI() throws RDFServiceException {
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String graphURI = null;
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return graphURI;
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}
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/**
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* Register a listener to listen to changes in any graph in
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* the RDF store.
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*
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* @return String URI of default read graph
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*/
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@Override
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public void registerListener(ChangeListener changeListener) throws RDFServiceException {
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}
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/**
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* Unregister a listener to listen to changes in any graph in
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* the RDF store.
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*
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* @return String URI of default read graph
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*/
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@Override
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public void unregisterListener(ChangeListener changeListener) throws RDFServiceException {
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}
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/**
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* Create a ChangeSet object
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*
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* @return a ChangeSet object
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*/
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@Override
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public ChangeSet manufactureChangeSet() {
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return new ChangeSetImpl();
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}
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//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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// Non override methods below
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//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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protected String getEndpointURI() {
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return endpointURI;
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}
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protected RepositoryConnection getConnection() {
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try {
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return this.repository.getConnection();
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} catch (RepositoryException e) {
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throw new RuntimeException(e);
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}
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}
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protected void executeUpdate(String updateString) {
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try {
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RepositoryConnection conn = getConnection();
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try {
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Update u = conn.prepareUpdate(QueryLanguage.SPARQL, updateString);
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u.execute();
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} catch (MalformedQueryException e) {
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throw new RuntimeException(e);
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} catch (UpdateExecutionException e) {
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log.error(e,e);
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log.error("Update command: \n" + updateString);
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throw new RuntimeException(e);
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} finally {
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conn.close();
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}
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} catch (RepositoryException re) {
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throw new RuntimeException(re);
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}
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}
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protected void addTriple(Triple t, String graphURI) {
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//log.info("adding " + t);
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String updateString = "INSERT DATA { " + ((graphURI != null) ? "GRAPH <" + graphURI + "> { " : "" )
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+ sparqlNodeUpdate(t.getSubject(), "") + " "
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+ sparqlNodeUpdate(t.getPredicate(), "") + " "
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+ sparqlNodeUpdate(t.getObject(), "") + " } "
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+ ((graphURI != null) ? " } " : "");
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//log.info(updateString);
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executeUpdate(updateString);
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}
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protected void removeTriple(Triple t, String graphURI) {
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String updateString = "DELETE DATA { " + ((graphURI != null) ? "GRAPH <" + graphURI + "> { " : "" )
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+ sparqlNodeUpdate(t.getSubject(), "") + " "
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+ sparqlNodeUpdate(t.getPredicate(), "") + " "
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+ sparqlNodeUpdate(t.getObject(), "") + " } "
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+ ((graphURI != null) ? " } " : "");
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//log.info(updateString);
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executeUpdate(updateString);
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}
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protected boolean isPreconditionSatisfied(String query,
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RDFService.SPARQLQueryType queryType)
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throws RDFServiceException {
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Model model = ModelFactory.createDefaultModel();
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switch (queryType) {
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case DESCRIBE:
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model.read(sparqlDescribeQuery(query,RDFService.ModelSerializationFormat.N3), null);
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return !model.isEmpty();
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case CONSTRUCT:
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model.read(sparqlConstructQuery(query,RDFService.ModelSerializationFormat.N3), null);
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return !model.isEmpty();
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case SELECT:
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return sparqlSelectQueryHasResults(query);
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case ASK:
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return sparqlAskQuery(query);
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default:
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throw new RDFServiceException("unrecognized SPARQL query type");
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
protected boolean sparqlSelectQueryHasResults(String queryStr) throws RDFServiceException {
|
||||
|
||||
Query query = QueryFactory.create(queryStr);
|
||||
QueryExecution qe = QueryExecutionFactory.sparqlService(endpointURI, query);
|
||||
|
||||
try {
|
||||
ResultSet resultSet = qe.execSelect();
|
||||
return resultSet.hasNext();
|
||||
} finally {
|
||||
qe.close();
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
protected void performAdd(ModelChange modelChange) throws RDFServiceException {
|
||||
|
||||
Model model = ModelFactory.createDefaultModel();
|
||||
model.read(modelChange.getSerializedModel(),getSerializationFormatString(modelChange.getSerializationFormat()));
|
||||
|
||||
StmtIterator stmtIt = model.listStatements();
|
||||
|
||||
while (stmtIt.hasNext()) {
|
||||
Statement stmt = stmtIt.next();
|
||||
Triple triple = new Triple(stmt.getSubject().asNode(), stmt.getPredicate().asNode(), stmt.getObject().asNode());
|
||||
addTriple(triple, modelChange.getGraphURI());
|
||||
}
|
||||
}
|
||||
|
||||
protected void performRemove(ModelChange modelChange) throws RDFServiceException {
|
||||
|
||||
Model model = ModelFactory.createDefaultModel();
|
||||
model.read(modelChange.getSerializedModel(),getSerializationFormatString(modelChange.getSerializationFormat()));
|
||||
|
||||
StmtIterator stmtIt = model.listStatements();
|
||||
|
||||
while (stmtIt.hasNext()) {
|
||||
Statement stmt = stmtIt.next();
|
||||
Triple triple = new Triple(stmt.getSubject().asNode(), stmt.getPredicate().asNode(), stmt.getObject().asNode());
|
||||
removeTriple(triple, modelChange.getGraphURI());
|
||||
}
|
||||
}
|
||||
|
||||
protected static String getSerializationFormatString(RDFService.ModelSerializationFormat format) {
|
||||
switch (format) {
|
||||
case RDFXML:
|
||||
return "RDFXML";
|
||||
case N3:
|
||||
return "N3";
|
||||
default:
|
||||
log.error("unexpected format in getFormatString");
|
||||
return null;
|
||||
}
|
||||
}
|
||||
|
||||
protected static String sparqlNodeUpdate(Node node, String varName) {
|
||||
if (node.isBlank()) {
|
||||
return "_:" + node.getBlankNodeLabel().replaceAll("\\W", "");
|
||||
} else {
|
||||
return sparqlNode(node, varName);
|
||||
}
|
||||
}
|
||||
|
||||
protected static String sparqlNode(Node node, String varName) {
|
||||
if (node == null || node.isVariable()) {
|
||||
return varName;
|
||||
} else if (node.isBlank()) {
|
||||
return "<fake:blank>"; // or throw exception?
|
||||
} else if (node.isURI()) {
|
||||
StringBuffer uriBuff = new StringBuffer();
|
||||
return uriBuff.append("<").append(node.getURI()).append(">").toString();
|
||||
} else if (node.isLiteral()) {
|
||||
StringBuffer literalBuff = new StringBuffer();
|
||||
literalBuff.append("\"");
|
||||
pyString(literalBuff, node.getLiteralLexicalForm());
|
||||
literalBuff.append("\"");
|
||||
if (node.getLiteralDatatypeURI() != null) {
|
||||
literalBuff.append("^^<").append(node.getLiteralDatatypeURI()).append(">");
|
||||
} else if (node.getLiteralLanguage() != null && node.getLiteralLanguage() != "") {
|
||||
literalBuff.append("@").append(node.getLiteralLanguage());
|
||||
}
|
||||
return literalBuff.toString();
|
||||
} else {
|
||||
return varName;
|
||||
}
|
||||
}
|
||||
|
||||
// see http://www.python.org/doc/2.5.2/ref/strings.html
|
||||
// or see jena's n3 grammar jena/src/com/hp/hpl/jena/n3/n3.g
|
||||
protected static void pyString(StringBuffer sbuff, String s) {
|
||||
for (int i = 0; i < s.length(); i++) {
|
||||
char c = s.charAt(i);
|
||||
|
||||
// Escape escapes and quotes
|
||||
if (c == '\\' || c == '"' )
|
||||
{
|
||||
sbuff.append('\\') ;
|
||||
sbuff.append(c) ;
|
||||
continue ;
|
||||
}
|
||||
|
||||
// Whitespace
|
||||
if (c == '\n'){ sbuff.append("\\n");continue; }
|
||||
if (c == '\t'){ sbuff.append("\\t");continue; }
|
||||
if (c == '\r'){ sbuff.append("\\r");continue; }
|
||||
if (c == '\f'){ sbuff.append("\\f");continue; }
|
||||
if (c == '\b'){ sbuff.append("\\b");continue; }
|
||||
if( c == 7 ) { sbuff.append("\\a");continue; }
|
||||
|
||||
// Output as is (subject to UTF-8 encoding on output that is)
|
||||
sbuff.append(c) ;
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Add table
Add a link
Reference in a new issue